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diff --git a/ffmpeg/doc/ffmpeg-formats.html b/ffmpeg/doc/ffmpeg-formats.html new file mode 100644 index 0000000..fc3e8cb --- /dev/null +++ b/ffmpeg/doc/ffmpeg-formats.html @@ -0,0 +1,4849 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Created by GNU Texinfo 6.8, https://www.gnu.org/software/texinfo/ --> + <head> + <meta charset="utf-8"> + <title> + FFmpeg Formats Documentation + </title> + <meta name="viewport" content="width=device-width,initial-scale=1.0"> + <link rel="stylesheet" type="text/css" href="bootstrap.min.css"> + <link rel="stylesheet" type="text/css" href="style.min.css"> + </head> + <body> + <div class="container"> + <h1> + FFmpeg Formats Documentation + </h1> +<div align="center"> +</div> + + +<a name="SEC_Top"></a> + +<div class="Contents_element" id="SEC_Contents"> +<h2 class="contents-heading">Table of Contents</h2> + +<div class="contents"> + +<ul class="no-bullet"> + <li><a id="toc-Description" href="#Description">1 Description</a></li> + <li><a id="toc-Format-Options" href="#Format-Options">2 Format Options</a> + <ul class="no-bullet"> + <li><a id="toc-Format-stream-specifiers-1" href="#Format-stream-specifiers-1">2.1 Format stream specifiers</a></li> + </ul></li> + <li><a id="toc-Demuxers" href="#Demuxers">3 Demuxers</a> + <ul class="no-bullet"> + <li><a id="toc-aa" href="#aa">3.1 aa</a></li> + <li><a id="toc-aac" href="#aac">3.2 aac</a></li> + <li><a id="toc-apng" href="#apng">3.3 apng</a></li> + <li><a id="toc-asf-1" href="#asf-1">3.4 asf</a></li> + <li><a id="toc-concat-1" href="#concat-1">3.5 concat</a> + <ul class="no-bullet"> + <li><a id="toc-Syntax" href="#Syntax">3.5.1 Syntax</a></li> + <li><a id="toc-Options" href="#Options">3.5.2 Options</a></li> + <li><a id="toc-Examples" href="#Examples">3.5.3 Examples</a></li> + </ul></li> + <li><a id="toc-dash-1" href="#dash-1">3.6 dash</a> + <ul class="no-bullet"> + <li><a id="toc-Options-1" href="#Options-1">3.6.1 Options</a></li> + </ul></li> + <li><a id="toc-imf" href="#imf">3.7 imf</a></li> + <li><a id="toc-flv_002c-live_005fflv_002c-kux" href="#flv_002c-live_005fflv_002c-kux">3.8 flv, live_flv, kux</a></li> + <li><a id="toc-gif-1" href="#gif-1">3.9 gif</a></li> + <li><a id="toc-hls-1" href="#hls-1">3.10 hls</a></li> + <li><a id="toc-image2-1" href="#image2-1">3.11 image2</a> + <ul class="no-bullet"> + <li><a id="toc-Examples-1" href="#Examples-1">3.11.1 Examples</a></li> + </ul></li> + <li><a id="toc-libgme" href="#libgme">3.12 libgme</a></li> + <li><a id="toc-libmodplug" href="#libmodplug">3.13 libmodplug</a></li> + <li><a id="toc-libopenmpt" href="#libopenmpt">3.14 libopenmpt</a></li> + <li><a id="toc-mov_002fmp4_002f3gp" href="#mov_002fmp4_002f3gp">3.15 mov/mp4/3gp</a> + <ul class="no-bullet"> + <li><a id="toc-Options-2" href="#Options-2">3.15.1 Options</a></li> + <li><a id="toc-Audible-AAX" href="#Audible-AAX">3.15.2 Audible AAX</a></li> + </ul></li> + <li><a id="toc-mpegts" href="#mpegts">3.16 mpegts</a></li> + <li><a id="toc-mpjpeg" href="#mpjpeg">3.17 mpjpeg</a></li> + <li><a id="toc-rawvideo" href="#rawvideo">3.18 rawvideo</a></li> + <li><a id="toc-sbg" href="#sbg">3.19 sbg</a></li> + <li><a id="toc-tedcaptions" href="#tedcaptions">3.20 tedcaptions</a></li> + <li><a id="toc-vapoursynth" href="#vapoursynth">3.21 vapoursynth</a></li> + </ul></li> + <li><a id="toc-Muxers" href="#Muxers">4 Muxers</a> + <ul class="no-bullet"> + <li><a id="toc-a64-1" href="#a64-1">4.1 a64</a></li> + <li><a id="toc-adts-1" href="#adts-1">4.2 adts</a> + <ul class="no-bullet"> + <li><a id="toc-Options-3" href="#Options-3">4.2.1 Options</a></li> + </ul></li> + <li><a id="toc-aiff-1" href="#aiff-1">4.3 aiff</a> + <ul class="no-bullet"> + <li><a id="toc-Options-4" href="#Options-4">4.3.1 Options</a></li> + </ul></li> + <li><a id="toc-alp-1" href="#alp-1">4.4 alp</a> + <ul class="no-bullet"> + <li><a id="toc-Options-5" href="#Options-5">4.4.1 Options</a></li> + </ul></li> + <li><a id="toc-asf-2" href="#asf-2">4.5 asf</a> + <ul class="no-bullet"> + <li><a id="toc-Options-6" href="#Options-6">4.5.1 Options</a></li> + </ul></li> + <li><a id="toc-avi-1" href="#avi-1">4.6 avi</a> + <ul class="no-bullet"> + <li><a id="toc-Options-7" href="#Options-7">4.6.1 Options</a></li> + </ul></li> + <li><a id="toc-chromaprint-1" href="#chromaprint-1">4.7 chromaprint</a> + <ul class="no-bullet"> + <li><a id="toc-Options-8" href="#Options-8">4.7.1 Options</a></li> + </ul></li> + <li><a id="toc-crc-1" href="#crc-1">4.8 crc</a> + <ul class="no-bullet"> + <li><a id="toc-Examples-2" href="#Examples-2">4.8.1 Examples</a></li> + </ul></li> + <li><a id="toc-dash-2" href="#dash-2">4.9 dash</a></li> + <li><a id="toc-fifo-1" href="#fifo-1">4.10 fifo</a> + <ul class="no-bullet"> + <li><a id="toc-Examples-3" href="#Examples-3">4.10.1 Examples</a></li> + </ul></li> + <li><a id="toc-flv" href="#flv">4.11 flv</a></li> + <li><a id="toc-framecrc-1" href="#framecrc-1">4.12 framecrc</a> + <ul class="no-bullet"> + <li><a id="toc-Examples-4" href="#Examples-4">4.12.1 Examples</a></li> + </ul></li> + <li><a id="toc-framehash-1" href="#framehash-1">4.13 framehash</a> + <ul class="no-bullet"> + <li><a id="toc-Examples-5" href="#Examples-5">4.13.1 Examples</a></li> + </ul></li> + <li><a id="toc-framemd5-1" href="#framemd5-1">4.14 framemd5</a> + <ul class="no-bullet"> + <li><a id="toc-Examples-6" href="#Examples-6">4.14.1 Examples</a></li> + </ul></li> + <li><a id="toc-gif-2" href="#gif-2">4.15 gif</a></li> + <li><a id="toc-hash-1" href="#hash-1">4.16 hash</a> + <ul class="no-bullet"> + <li><a id="toc-Examples-7" href="#Examples-7">4.16.1 Examples</a></li> + </ul></li> + <li><a id="toc-hls-2" href="#hls-2">4.17 hls</a> + <ul class="no-bullet"> + <li><a id="toc-Options-9" href="#Options-9">4.17.1 Options</a></li> + </ul></li> + <li><a id="toc-ico-1" href="#ico-1">4.18 ico</a></li> + <li><a id="toc-image2-2" href="#image2-2">4.19 image2</a> + <ul class="no-bullet"> + <li><a id="toc-Options-10" href="#Options-10">4.19.1 Options</a></li> + <li><a id="toc-Examples-8" href="#Examples-8">4.19.2 Examples</a></li> + </ul></li> + <li><a id="toc-matroska" href="#matroska">4.20 matroska</a> + <ul class="no-bullet"> + <li><a id="toc-Metadata" href="#Metadata">4.20.1 Metadata</a></li> + <li><a id="toc-Options-11" href="#Options-11">4.20.2 Options</a></li> + </ul></li> + <li><a id="toc-md5-1" href="#md5-1">4.21 md5</a> + <ul class="no-bullet"> + <li><a id="toc-Examples-9" href="#Examples-9">4.21.1 Examples</a></li> + </ul></li> + <li><a id="toc-mov_002c-mp4_002c-ismv" href="#mov_002c-mp4_002c-ismv">4.22 mov, mp4, ismv</a> + <ul class="no-bullet"> + <li><a id="toc-Options-12" href="#Options-12">4.22.1 Options</a></li> + <li><a id="toc-Example" href="#Example">4.22.2 Example</a></li> + </ul></li> + <li><a id="toc-mp3" href="#mp3">4.23 mp3</a></li> + <li><a id="toc-mpegts-1" href="#mpegts-1">4.24 mpegts</a> + <ul class="no-bullet"> + <li><a id="toc-Options-13" href="#Options-13">4.24.1 Options</a></li> + <li><a id="toc-Example-1" href="#Example-1">4.24.2 Example</a></li> + </ul></li> + <li><a id="toc-mxf_002c-mxf_005fd10_002c-mxf_005fopatom" href="#mxf_002c-mxf_005fd10_002c-mxf_005fopatom">4.25 mxf, mxf_d10, mxf_opatom</a> + <ul class="no-bullet"> + <li><a id="toc-Options-14" href="#Options-14">4.25.1 Options</a></li> + </ul></li> + <li><a id="toc-null" href="#null">4.26 null</a></li> + <li><a id="toc-nut" href="#nut">4.27 nut</a></li> + <li><a id="toc-ogg" href="#ogg">4.28 ogg</a></li> + <li><a id="toc-raw-muxers-1" href="#raw-muxers-1">4.29 raw muxers</a> + <ul class="no-bullet"> + <li><a id="toc-ac3" href="#ac3">4.29.1 ac3</a></li> + <li><a id="toc-adx" href="#adx">4.29.2 adx</a></li> + <li><a id="toc-aptx" href="#aptx">4.29.3 aptx</a></li> + <li><a id="toc-aptx_005fhd" href="#aptx_005fhd">4.29.4 aptx_hd</a></li> + <li><a id="toc-avs2" href="#avs2">4.29.5 avs2</a></li> + <li><a id="toc-cavsvideo" href="#cavsvideo">4.29.6 cavsvideo</a></li> + <li><a id="toc-codec2raw" href="#codec2raw">4.29.7 codec2raw</a></li> + <li><a id="toc-data" href="#data">4.29.8 data</a></li> + <li><a id="toc-dirac" href="#dirac">4.29.9 dirac</a></li> + <li><a id="toc-dnxhd" href="#dnxhd">4.29.10 dnxhd</a></li> + <li><a id="toc-dts" href="#dts">4.29.11 dts</a></li> + <li><a id="toc-eac3" href="#eac3">4.29.12 eac3</a></li> + <li><a id="toc-g722" href="#g722">4.29.13 g722</a></li> + <li><a id="toc-g723_005f1" href="#g723_005f1">4.29.14 g723_1</a></li> + <li><a id="toc-g726" href="#g726">4.29.15 g726</a></li> + <li><a id="toc-g726le" href="#g726le">4.29.16 g726le</a></li> + <li><a id="toc-gsm" href="#gsm">4.29.17 gsm</a></li> + <li><a id="toc-h261" href="#h261">4.29.18 h261</a></li> + <li><a id="toc-h263" href="#h263">4.29.19 h263</a></li> + <li><a id="toc-h264" href="#h264">4.29.20 h264</a></li> + <li><a id="toc-hevc" href="#hevc">4.29.21 hevc</a></li> + <li><a id="toc-m4v" href="#m4v">4.29.22 m4v</a></li> + <li><a id="toc-mjpeg" href="#mjpeg">4.29.23 mjpeg</a></li> + <li><a id="toc-mlp" href="#mlp">4.29.24 mlp</a></li> + <li><a id="toc-mp2" href="#mp2">4.29.25 mp2</a></li> + <li><a id="toc-mpeg1video" href="#mpeg1video">4.29.26 mpeg1video</a></li> + <li><a id="toc-mpeg2video" href="#mpeg2video">4.29.27 mpeg2video</a></li> + <li><a id="toc-obu" href="#obu">4.29.28 obu</a></li> + <li><a id="toc-rawvideo-1" href="#rawvideo-1">4.29.29 rawvideo</a></li> + <li><a id="toc-sbc" href="#sbc">4.29.30 sbc</a></li> + <li><a id="toc-truehd" href="#truehd">4.29.31 truehd</a></li> + <li><a id="toc-vc1" href="#vc1">4.29.32 vc1</a></li> + </ul></li> + <li><a id="toc-segment_002c-stream_005fsegment_002c-ssegment" href="#segment_002c-stream_005fsegment_002c-ssegment">4.30 segment, stream_segment, ssegment</a> + <ul class="no-bullet"> + <li><a id="toc-Options-15" href="#Options-15">4.30.1 Options</a></li> + <li><a id="toc-Examples-10" href="#Examples-10">4.30.2 Examples</a></li> + </ul></li> + <li><a id="toc-smoothstreaming" href="#smoothstreaming">4.31 smoothstreaming</a></li> + <li><a id="toc-streamhash-1" href="#streamhash-1">4.32 streamhash</a> + <ul class="no-bullet"> + <li><a id="toc-Examples-11" href="#Examples-11">4.32.1 Examples</a></li> + </ul></li> + <li><a id="toc-tee-1" href="#tee-1">4.33 tee</a> + <ul class="no-bullet"> + <li><a id="toc-Options-16" href="#Options-16">4.33.1 Options</a></li> + <li><a id="toc-Examples-12" href="#Examples-12">4.33.2 Examples</a></li> + </ul></li> + <li><a id="toc-webm_005fchunk" href="#webm_005fchunk">4.34 webm_chunk</a> + <ul class="no-bullet"> + <li><a id="toc-Options-17" href="#Options-17">4.34.1 Options</a></li> + <li><a id="toc-Example-2" href="#Example-2">4.34.2 Example</a></li> + </ul></li> + <li><a id="toc-webm_005fdash_005fmanifest" href="#webm_005fdash_005fmanifest">4.35 webm_dash_manifest</a> + <ul class="no-bullet"> + <li><a id="toc-Options-18" href="#Options-18">4.35.1 Options</a></li> + <li><a id="toc-Example-3" href="#Example-3">4.35.2 Example</a></li> + </ul></li> + </ul></li> + <li><a id="toc-Metadata-1" href="#Metadata-1">5 Metadata</a></li> + <li><a id="toc-See-Also" href="#See-Also">6 See Also</a></li> + <li><a id="toc-Authors" href="#Authors">7 Authors</a></li> +</ul> +</div> +</div> + +<a name="Description"></a> +<h2 class="chapter">1 Description<span class="pull-right"><a class="anchor hidden-xs" href="#Description" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Description" aria-hidden="true">TOC</a></span></h2> + +<p>This document describes the supported formats (muxers and demuxers) +provided by the libavformat library. +</p> + +<a name="Format-Options"></a> +<h2 class="chapter">2 Format Options<span class="pull-right"><a class="anchor hidden-xs" href="#Format-Options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Format-Options" aria-hidden="true">TOC</a></span></h2> + +<p>The libavformat library provides some generic global options, which +can be set on all the muxers and demuxers. In addition each muxer or +demuxer may support so-called private options, which are specific for +that component. +</p> +<p>Options may be set by specifying -<var>option</var> <var>value</var> in the +FFmpeg tools, or by setting the value explicitly in the +<code>AVFormatContext</code> options or using the <samp>libavutil/opt.h</samp> API +for programmatic use. +</p> +<p>The list of supported options follows: +</p> +<dl compact="compact"> +<dt><span><samp>avioflags <var>flags</var> (<em>input/output</em>)</samp></span></dt> +<dd><p>Possible values: +</p><dl compact="compact"> +<dt><span>‘<samp>direct</samp>’</span></dt> +<dd><p>Reduce buffering. +</p></dd> +</dl> + +</dd> +<dt><span><samp>probesize <var>integer</var> (<em>input</em>)</samp></span></dt> +<dd><p>Set probing size in bytes, i.e. the size of the data to analyze to get +stream information. A higher value will enable detecting more +information in case it is dispersed into the stream, but will increase +latency. Must be an integer not lesser than 32. It is 5000000 by default. +</p> +</dd> +<dt><span><samp>max_probe_packets <var>integer</var> (<em>input</em>)</samp></span></dt> +<dd><p>Set the maximum number of buffered packets when probing a codec. +Default is 2500 packets. +</p> +</dd> +<dt><span><samp>packetsize <var>integer</var> (<em>output</em>)</samp></span></dt> +<dd><p>Set packet size. +</p> +</dd> +<dt><span><samp>fflags <var>flags</var></samp></span></dt> +<dd><p>Set format flags. Some are implemented for a limited number of formats. +</p> +<p>Possible values for input files: +</p><dl compact="compact"> +<dt><span>‘<samp>discardcorrupt</samp>’</span></dt> +<dd><p>Discard corrupted packets. +</p></dd> +<dt><span>‘<samp>fastseek</samp>’</span></dt> +<dd><p>Enable fast, but inaccurate seeks for some formats. +</p></dd> +<dt><span>‘<samp>genpts</samp>’</span></dt> +<dd><p>Generate missing PTS if DTS is present. +</p></dd> +<dt><span>‘<samp>igndts</samp>’</span></dt> +<dd><p>Ignore DTS if PTS is set. Inert when nofillin is set. +</p></dd> +<dt><span>‘<samp>ignidx</samp>’</span></dt> +<dd><p>Ignore index. +</p></dd> +<dt><span>‘<samp>nobuffer</samp>’</span></dt> +<dd><p>Reduce the latency introduced by buffering during initial input streams analysis. +</p></dd> +<dt><span>‘<samp>nofillin</samp>’</span></dt> +<dd><p>Do not fill in missing values in packet fields that can be exactly calculated. +</p></dd> +<dt><span>‘<samp>noparse</samp>’</span></dt> +<dd><p>Disable AVParsers, this needs <code>+nofillin</code> too. +</p></dd> +<dt><span>‘<samp>sortdts</samp>’</span></dt> +<dd><p>Try to interleave output packets by DTS. At present, available only for AVIs with an index. +</p></dd> +</dl> + +<p>Possible values for output files: +</p><dl compact="compact"> +<dt><span>‘<samp>autobsf</samp>’</span></dt> +<dd><p>Automatically apply bitstream filters as required by the output format. Enabled by default. +</p></dd> +<dt><span>‘<samp>bitexact</samp>’</span></dt> +<dd><p>Only write platform-, build- and time-independent data. +This ensures that file and data checksums are reproducible and match between +platforms. Its primary use is for regression testing. +</p></dd> +<dt><span>‘<samp>flush_packets</samp>’</span></dt> +<dd><p>Write out packets immediately. +</p></dd> +<dt><span>‘<samp>shortest</samp>’</span></dt> +<dd><p>Stop muxing at the end of the shortest stream. +It may be needed to increase max_interleave_delta to avoid flushing the longer +streams before EOF. +</p></dd> +</dl> + +</dd> +<dt><span><samp>seek2any <var>integer</var> (<em>input</em>)</samp></span></dt> +<dd><p>Allow seeking to non-keyframes on demuxer level when supported if set to 1. +Default is 0. +</p> +</dd> +<dt><span><samp>analyzeduration <var>integer</var> (<em>input</em>)</samp></span></dt> +<dd><p>Specify how many microseconds are analyzed to probe the input. A +higher value will enable detecting more accurate information, but will +increase latency. It defaults to 5,000,000 microseconds = 5 seconds. +</p> +</dd> +<dt><span><samp>cryptokey <var>hexadecimal string</var> (<em>input</em>)</samp></span></dt> +<dd><p>Set decryption key. +</p> +</dd> +<dt><span><samp>indexmem <var>integer</var> (<em>input</em>)</samp></span></dt> +<dd><p>Set max memory used for timestamp index (per stream). +</p> +</dd> +<dt><span><samp>rtbufsize <var>integer</var> (<em>input</em>)</samp></span></dt> +<dd><p>Set max memory used for buffering real-time frames. +</p> +</dd> +<dt><span><samp>fdebug <var>flags</var> (<em>input/output</em>)</samp></span></dt> +<dd><p>Print specific debug info. +</p> +<p>Possible values: +</p><dl compact="compact"> +<dt><span>‘<samp>ts</samp>’</span></dt> +</dl> + +</dd> +<dt><span><samp>max_delay <var>integer</var> (<em>input/output</em>)</samp></span></dt> +<dd><p>Set maximum muxing or demuxing delay in microseconds. +</p> +</dd> +<dt><span><samp>fpsprobesize <var>integer</var> (<em>input</em>)</samp></span></dt> +<dd><p>Set number of frames used to probe fps. +</p> +</dd> +<dt><span><samp>audio_preload <var>integer</var> (<em>output</em>)</samp></span></dt> +<dd><p>Set microseconds by which audio packets should be interleaved earlier. +</p> +</dd> +<dt><span><samp>chunk_duration <var>integer</var> (<em>output</em>)</samp></span></dt> +<dd><p>Set microseconds for each chunk. +</p> +</dd> +<dt><span><samp>chunk_size <var>integer</var> (<em>output</em>)</samp></span></dt> +<dd><p>Set size in bytes for each chunk. +</p> +</dd> +<dt><span><samp>err_detect, f_err_detect <var>flags</var> (<em>input</em>)</samp></span></dt> +<dd><p>Set error detection flags. <code>f_err_detect</code> is deprecated and +should be used only via the <code>ffmpeg</code> tool. +</p> +<p>Possible values: +</p><dl compact="compact"> +<dt><span>‘<samp>crccheck</samp>’</span></dt> +<dd><p>Verify embedded CRCs. +</p></dd> +<dt><span>‘<samp>bitstream</samp>’</span></dt> +<dd><p>Detect bitstream specification deviations. +</p></dd> +<dt><span>‘<samp>buffer</samp>’</span></dt> +<dd><p>Detect improper bitstream length. +</p></dd> +<dt><span>‘<samp>explode</samp>’</span></dt> +<dd><p>Abort decoding on minor error detection. +</p></dd> +<dt><span>‘<samp>careful</samp>’</span></dt> +<dd><p>Consider things that violate the spec and have not been seen in the +wild as errors. +</p></dd> +<dt><span>‘<samp>compliant</samp>’</span></dt> +<dd><p>Consider all spec non compliancies as errors. +</p></dd> +<dt><span>‘<samp>aggressive</samp>’</span></dt> +<dd><p>Consider things that a sane encoder should not do as an error. +</p></dd> +</dl> + +</dd> +<dt><span><samp>max_interleave_delta <var>integer</var> (<em>output</em>)</samp></span></dt> +<dd><p>Set maximum buffering duration for interleaving. The duration is +expressed in microseconds, and defaults to 10000000 (10 seconds). +</p> +<p>To ensure all the streams are interleaved correctly, libavformat will +wait until it has at least one packet for each stream before actually +writing any packets to the output file. When some streams are +"sparse" (i.e. there are large gaps between successive packets), this +can result in excessive buffering. +</p> +<p>This field specifies the maximum difference between the timestamps of the +first and the last packet in the muxing queue, above which libavformat +will output a packet regardless of whether it has queued a packet for all +the streams. +</p> +<p>If set to 0, libavformat will continue buffering packets until it has +a packet for each stream, regardless of the maximum timestamp +difference between the buffered packets. +</p> +</dd> +<dt><span><samp>use_wallclock_as_timestamps <var>integer</var> (<em>input</em>)</samp></span></dt> +<dd><p>Use wallclock as timestamps if set to 1. Default is 0. +</p> +</dd> +<dt><span><samp>avoid_negative_ts <var>integer</var> (<em>output</em>)</samp></span></dt> +<dd> +<p>Possible values: +</p><dl compact="compact"> +<dt><span>‘<samp>make_non_negative</samp>’</span></dt> +<dd><p>Shift timestamps to make them non-negative. +Also note that this affects only leading negative timestamps, and not +non-monotonic negative timestamps. +</p></dd> +<dt><span>‘<samp>make_zero</samp>’</span></dt> +<dd><p>Shift timestamps so that the first timestamp is 0. +</p></dd> +<dt><span>‘<samp>auto (default)</samp>’</span></dt> +<dd><p>Enables shifting when required by the target format. +</p></dd> +<dt><span>‘<samp>disabled</samp>’</span></dt> +<dd><p>Disables shifting of timestamp. +</p></dd> +</dl> + +<p>When shifting is enabled, all output timestamps are shifted by the +same amount. Audio, video, and subtitles desynching and relative +timestamp differences are preserved compared to how they would have +been without shifting. +</p> +</dd> +<dt><span><samp>skip_initial_bytes <var>integer</var> (<em>input</em>)</samp></span></dt> +<dd><p>Set number of bytes to skip before reading header and frames if set to 1. +Default is 0. +</p> +</dd> +<dt><span><samp>correct_ts_overflow <var>integer</var> (<em>input</em>)</samp></span></dt> +<dd><p>Correct single timestamp overflows if set to 1. Default is 1. +</p> +</dd> +<dt><span><samp>flush_packets <var>integer</var> (<em>output</em>)</samp></span></dt> +<dd><p>Flush the underlying I/O stream after each packet. Default is -1 (auto), which +means that the underlying protocol will decide, 1 enables it, and has the +effect of reducing the latency, 0 disables it and may increase IO throughput in +some cases. +</p> +</dd> +<dt><span><samp>output_ts_offset <var>offset</var> (<em>output</em>)</samp></span></dt> +<dd><p>Set the output time offset. +</p> +<p><var>offset</var> must be a time duration specification, +see <a data-manual="ffmpeg-utils" href="ffmpeg-utils.html#time-duration-syntax">(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual</a>. +</p> +<p>The offset is added by the muxer to the output timestamps. +</p> +<p>Specifying a positive offset means that the corresponding streams are +delayed bt the time duration specified in <var>offset</var>. Default value +is <code>0</code> (meaning that no offset is applied). +</p> +</dd> +<dt><span><samp>format_whitelist <var>list</var> (<em>input</em>)</samp></span></dt> +<dd><p>"," separated list of allowed demuxers. By default all are allowed. +</p> +</dd> +<dt><span><samp>dump_separator <var>string</var> (<em>input</em>)</samp></span></dt> +<dd><p>Separator used to separate the fields printed on the command line about the +Stream parameters. +For example, to separate the fields with newlines and indentation: +</p><div class="example"> +<pre class="example">ffprobe -dump_separator " + " -i ~/videos/matrixbench_mpeg2.mpg +</pre></div> + +</dd> +<dt><span><samp>max_streams <var>integer</var> (<em>input</em>)</samp></span></dt> +<dd><p>Specifies the maximum number of streams. This can be used to reject files that +would require too many resources due to a large number of streams. +</p> +</dd> +<dt><span><samp>skip_estimate_duration_from_pts <var>bool</var> (<em>input</em>)</samp></span></dt> +<dd><p>Skip estimation of input duration when calculated using PTS. +At present, applicable for MPEG-PS and MPEG-TS. +</p> +</dd> +<dt><span><samp>strict, f_strict <var>integer</var> (<em>input/output</em>)</samp></span></dt> +<dd><p>Specify how strictly to follow the standards. <code>f_strict</code> is deprecated and +should be used only via the <code>ffmpeg</code> tool. +</p> +<p>Possible values: +</p><dl compact="compact"> +<dt><span>‘<samp>very</samp>’</span></dt> +<dd><p>strictly conform to an older more strict version of the spec or reference software +</p></dd> +<dt><span>‘<samp>strict</samp>’</span></dt> +<dd><p>strictly conform to all the things in the spec no matter what consequences +</p></dd> +<dt><span>‘<samp>normal</samp>’</span></dt> +<dt><span>‘<samp>unofficial</samp>’</span></dt> +<dd><p>allow unofficial extensions +</p></dd> +<dt><span>‘<samp>experimental</samp>’</span></dt> +<dd><p>allow non standardized experimental things, experimental +(unfinished/work in progress/not well tested) decoders and encoders. +Note: experimental decoders can pose a security risk, do not use this for +decoding untrusted input. +</p></dd> +</dl> + +</dd> +</dl> + + +<span id="Format-stream-specifiers"></span><a name="Format-stream-specifiers-1"></a> +<h3 class="section">2.1 Format stream specifiers<span class="pull-right"><a class="anchor hidden-xs" href="#Format-stream-specifiers-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Format-stream-specifiers-1" aria-hidden="true">TOC</a></span></h3> + +<p>Format stream specifiers allow selection of one or more streams that +match specific properties. +</p> +<p>The exact semantics of stream specifiers is defined by the +<code>avformat_match_stream_specifier()</code> function declared in the +<samp>libavformat/avformat.h</samp> header and documented in the +<a data-manual="ffmpeg" href="ffmpeg.html#Stream-specifiers">(ffmpeg)Stream specifiers section in the ffmpeg(1) manual</a>. +</p> +<a name="Demuxers"></a> +<h2 class="chapter">3 Demuxers<span class="pull-right"><a class="anchor hidden-xs" href="#Demuxers" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Demuxers" aria-hidden="true">TOC</a></span></h2> + +<p>Demuxers are configured elements in FFmpeg that can read the +multimedia streams from a particular type of file. +</p> +<p>When you configure your FFmpeg build, all the supported demuxers +are enabled by default. You can list all available ones using the +configure option <code>--list-demuxers</code>. +</p> +<p>You can disable all the demuxers using the configure option +<code>--disable-demuxers</code>, and selectively enable a single demuxer with +the option <code>--enable-demuxer=<var>DEMUXER</var></code>, or disable it +with the option <code>--disable-demuxer=<var>DEMUXER</var></code>. +</p> +<p>The option <code>-demuxers</code> of the ff* tools will display the list of +enabled demuxers. Use <code>-formats</code> to view a combined list of +enabled demuxers and muxers. +</p> +<p>The description of some of the currently available demuxers follows. +</p> +<a name="aa"></a> +<h3 class="section">3.1 aa<span class="pull-right"><a class="anchor hidden-xs" href="#aa" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-aa" aria-hidden="true">TOC</a></span></h3> + +<p>Audible Format 2, 3, and 4 demuxer. +</p> +<p>This demuxer is used to demux Audible Format 2, 3, and 4 (.aa) files. +</p> +<a name="aac"></a> +<h3 class="section">3.2 aac<span class="pull-right"><a class="anchor hidden-xs" href="#aac" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-aac" aria-hidden="true">TOC</a></span></h3> + +<p>Raw Audio Data Transport Stream AAC demuxer. +</p> +<p>This demuxer is used to demux an ADTS input containing a single AAC stream +alongwith any ID3v1/2 or APE tags in it. +</p> +<a name="apng"></a> +<h3 class="section">3.3 apng<span class="pull-right"><a class="anchor hidden-xs" href="#apng" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-apng" aria-hidden="true">TOC</a></span></h3> + +<p>Animated Portable Network Graphics demuxer. +</p> +<p>This demuxer is used to demux APNG files. +All headers, but the PNG signature, up to (but not including) the first +fcTL chunk are transmitted as extradata. +Frames are then split as being all the chunks between two fcTL ones, or +between the last fcTL and IEND chunks. +</p> +<dl compact="compact"> +<dt><span><samp>-ignore_loop <var>bool</var></samp></span></dt> +<dd><p>Ignore the loop variable in the file if set. Default is enabled. +</p> +</dd> +<dt><span><samp>-max_fps <var>int</var></samp></span></dt> +<dd><p>Maximum framerate in frames per second. Default of 0 imposes no limit. +</p> +</dd> +<dt><span><samp>-default_fps <var>int</var></samp></span></dt> +<dd><p>Default framerate in frames per second when none is specified in the file +(0 meaning as fast as possible). Default is 15. +</p> +</dd> +</dl> + +<a name="asf-1"></a> +<h3 class="section">3.4 asf<span class="pull-right"><a class="anchor hidden-xs" href="#asf-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-asf-1" aria-hidden="true">TOC</a></span></h3> + +<p>Advanced Systems Format demuxer. +</p> +<p>This demuxer is used to demux ASF files and MMS network streams. +</p> +<dl compact="compact"> +<dt><span><samp>-no_resync_search <var>bool</var></samp></span></dt> +<dd><p>Do not try to resynchronize by looking for a certain optional start code. +</p></dd> +</dl> + +<span id="concat"></span><a name="concat-1"></a> +<h3 class="section">3.5 concat<span class="pull-right"><a class="anchor hidden-xs" href="#concat-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-concat-1" aria-hidden="true">TOC</a></span></h3> + +<p>Virtual concatenation script demuxer. +</p> +<p>This demuxer reads a list of files and other directives from a text file and +demuxes them one after the other, as if all their packets had been muxed +together. +</p> +<p>The timestamps in the files are adjusted so that the first file starts at 0 +and each next file starts where the previous one finishes. Note that it is +done globally and may cause gaps if all streams do not have exactly the same +length. +</p> +<p>All files must have the same streams (same codecs, same time base, etc.). +</p> +<p>The duration of each file is used to adjust the timestamps of the next file: +if the duration is incorrect (because it was computed using the bit-rate or +because the file is truncated, for example), it can cause artifacts. The +<code>duration</code> directive can be used to override the duration stored in +each file. +</p> +<a name="Syntax"></a> +<h4 class="subsection">3.5.1 Syntax<span class="pull-right"><a class="anchor hidden-xs" href="#Syntax" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Syntax" aria-hidden="true">TOC</a></span></h4> + +<p>The script is a text file in extended-ASCII, with one directive per line. +Empty lines, leading spaces and lines starting with ’#’ are ignored. The +following directive is recognized: +</p> +<dl compact="compact"> +<dt><span><samp><code>file <var>path</var></code></samp></span></dt> +<dd><p>Path to a file to read; special characters and spaces must be escaped with +backslash or single quotes. +</p> +<p>All subsequent file-related directives apply to that file. +</p> +</dd> +<dt><span><samp><code>ffconcat version 1.0</code></samp></span></dt> +<dd><p>Identify the script type and version. +</p> +<p>To make FFmpeg recognize the format automatically, this directive must +appear exactly as is (no extra space or byte-order-mark) on the very first +line of the script. +</p> +</dd> +<dt><span><samp><code>duration <var>dur</var></code></samp></span></dt> +<dd><p>Duration of the file. This information can be specified from the file; +specifying it here may be more efficient or help if the information from the +file is not available or accurate. +</p> +<p>If the duration is set for all files, then it is possible to seek in the +whole concatenated video. +</p> +</dd> +<dt><span><samp><code>inpoint <var>timestamp</var></code></samp></span></dt> +<dd><p>In point of the file. When the demuxer opens the file it instantly seeks to the +specified timestamp. Seeking is done so that all streams can be presented +successfully at In point. +</p> +<p>This directive works best with intra frame codecs, because for non-intra frame +ones you will usually get extra packets before the actual In point and the +decoded content will most likely contain frames before In point too. +</p> +<p>For each file, packets before the file In point will have timestamps less than +the calculated start timestamp of the file (negative in case of the first +file), and the duration of the files (if not specified by the <code>duration</code> +directive) will be reduced based on their specified In point. +</p> +<p>Because of potential packets before the specified In point, packet timestamps +may overlap between two concatenated files. +</p> +</dd> +<dt><span><samp><code>outpoint <var>timestamp</var></code></samp></span></dt> +<dd><p>Out point of the file. When the demuxer reaches the specified decoding +timestamp in any of the streams, it handles it as an end of file condition and +skips the current and all the remaining packets from all streams. +</p> +<p>Out point is exclusive, which means that the demuxer will not output packets +with a decoding timestamp greater or equal to Out point. +</p> +<p>This directive works best with intra frame codecs and formats where all streams +are tightly interleaved. For non-intra frame codecs you will usually get +additional packets with presentation timestamp after Out point therefore the +decoded content will most likely contain frames after Out point too. If your +streams are not tightly interleaved you may not get all the packets from all +streams before Out point and you may only will be able to decode the earliest +stream until Out point. +</p> +<p>The duration of the files (if not specified by the <code>duration</code> +directive) will be reduced based on their specified Out point. +</p> +</dd> +<dt><span><samp><code>file_packet_metadata <var>key=value</var></code></samp></span></dt> +<dd><p>Metadata of the packets of the file. The specified metadata will be set for +each file packet. You can specify this directive multiple times to add multiple +metadata entries. +This directive is deprecated, use <code>file_packet_meta</code> instead. +</p> +</dd> +<dt><span><samp><code>file_packet_meta <var>key</var> <var>value</var></code></samp></span></dt> +<dd><p>Metadata of the packets of the file. The specified metadata will be set for +each file packet. You can specify this directive multiple times to add multiple +metadata entries. +</p> +</dd> +<dt><span><samp><code>option <var>key</var> <var>value</var></code></samp></span></dt> +<dd><p>Option to access, open and probe the file. +Can be present multiple times. +</p> +</dd> +<dt><span><samp><code>stream</code></samp></span></dt> +<dd><p>Introduce a stream in the virtual file. +All subsequent stream-related directives apply to the last introduced +stream. +Some streams properties must be set in order to allow identifying the +matching streams in the subfiles. +If no streams are defined in the script, the streams from the first file are +copied. +</p> +</dd> +<dt><span><samp><code>exact_stream_id <var>id</var></code></samp></span></dt> +<dd><p>Set the id of the stream. +If this directive is given, the string with the corresponding id in the +subfiles will be used. +This is especially useful for MPEG-PS (VOB) files, where the order of the +streams is not reliable. +</p> +</dd> +<dt><span><samp><code>stream_meta <var>key</var> <var>value</var></code></samp></span></dt> +<dd><p>Metadata for the stream. +Can be present multiple times. +</p> +</dd> +<dt><span><samp><code>stream_codec <var>value</var></code></samp></span></dt> +<dd><p>Codec for the stream. +</p> +</dd> +<dt><span><samp><code>stream_extradata <var>hex_string</var></code></samp></span></dt> +<dd><p>Extradata for the string, encoded in hexadecimal. +</p> +</dd> +<dt><span><samp><code>chapter <var>id</var> <var>start</var> <var>end</var></code></samp></span></dt> +<dd><p>Add a chapter. <var>id</var> is an unique identifier, possibly small and +consecutive. +</p> +</dd> +</dl> + +<a name="Options"></a> +<h4 class="subsection">3.5.2 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options" aria-hidden="true">TOC</a></span></h4> + +<p>This demuxer accepts the following option: +</p> +<dl compact="compact"> +<dt><span><samp>safe</samp></span></dt> +<dd><p>If set to 1, reject unsafe file paths and directives. +A file path is considered safe if it +does not contain a protocol specification and is relative and all components +only contain characters from the portable character set (letters, digits, +period, underscore and hyphen) and have no period at the beginning of a +component. +</p> +<p>If set to 0, any file name is accepted. +</p> +<p>The default is 1. +</p> +</dd> +<dt><span><samp>auto_convert</samp></span></dt> +<dd><p>If set to 1, try to perform automatic conversions on packet data to make the +streams concatenable. +The default is 1. +</p> +<p>Currently, the only conversion is adding the h264_mp4toannexb bitstream +filter to H.264 streams in MP4 format. This is necessary in particular if +there are resolution changes. +</p> +</dd> +<dt><span><samp>segment_time_metadata</samp></span></dt> +<dd><p>If set to 1, every packet will contain the <var>lavf.concat.start_time</var> and the +<var>lavf.concat.duration</var> packet metadata values which are the start_time and +the duration of the respective file segments in the concatenated output +expressed in microseconds. The duration metadata is only set if it is known +based on the concat file. +The default is 0. +</p> +</dd> +</dl> + +<a name="Examples"></a> +<h4 class="subsection">3.5.3 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples" aria-hidden="true">TOC</a></span></h4> + +<ul> +<li> Use absolute filenames and include some comments: +<div class="example"> +<pre class="example"># my first filename +file /mnt/share/file-1.wav +# my second filename including whitespace +file '/mnt/share/file 2.wav' +# my third filename including whitespace plus single quote +file '/mnt/share/file 3'\''.wav' +</pre></div> + +</li><li> Allow for input format auto-probing, use safe filenames and set the duration of +the first file: +<div class="example"> +<pre class="example">ffconcat version 1.0 + +file file-1.wav +duration 20.0 + +file subdir/file-2.wav +</pre></div> +</li></ul> + +<a name="dash-1"></a> +<h3 class="section">3.6 dash<span class="pull-right"><a class="anchor hidden-xs" href="#dash-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-dash-1" aria-hidden="true">TOC</a></span></h3> + +<p>Dynamic Adaptive Streaming over HTTP demuxer. +</p> +<p>This demuxer presents all AVStreams found in the manifest. +By setting the discard flags on AVStreams the caller can decide +which streams to actually receive. +Each stream mirrors the <code>id</code> and <code>bandwidth</code> properties from the +<code><Representation></code> as metadata keys named "id" and "variant_bitrate" respectively. +</p> +<a name="Options-1"></a> +<h4 class="subsection">3.6.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-1" aria-hidden="true">TOC</a></span></h4> + +<p>This demuxer accepts the following option: +</p> +<dl compact="compact"> +<dt><span><samp>cenc_decryption_key</samp></span></dt> +<dd><p>16-byte key, in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR; ISO/IEC 23001-7). +</p> +</dd> +</dl> + +<a name="imf"></a> +<h3 class="section">3.7 imf<span class="pull-right"><a class="anchor hidden-xs" href="#imf" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-imf" aria-hidden="true">TOC</a></span></h3> + +<p>Interoperable Master Format demuxer. +</p> +<p>This demuxer presents audio and video streams found in an IMF Composition. +</p> +<a name="flv_002c-live_005fflv_002c-kux"></a> +<h3 class="section">3.8 flv, live_flv, kux<span class="pull-right"><a class="anchor hidden-xs" href="#flv_002c-live_005fflv_002c-kux" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-flv_002c-live_005fflv_002c-kux" aria-hidden="true">TOC</a></span></h3> + +<p>Adobe Flash Video Format demuxer. +</p> +<p>This demuxer is used to demux FLV files and RTMP network streams. In case of live network streams, if you force format, you may use live_flv option instead of flv to survive timestamp discontinuities. +KUX is a flv variant used on the Youku platform. +</p> +<div class="example"> +<pre class="example">ffmpeg -f flv -i myfile.flv ... +ffmpeg -f live_flv -i rtmp://<any.server>/anything/key .... +</pre></div> + + +<dl compact="compact"> +<dt><span><samp>-flv_metadata <var>bool</var></samp></span></dt> +<dd><p>Allocate the streams according to the onMetaData array content. +</p> +</dd> +<dt><span><samp>-flv_ignore_prevtag <var>bool</var></samp></span></dt> +<dd><p>Ignore the size of previous tag value. +</p> +</dd> +<dt><span><samp>-flv_full_metadata <var>bool</var></samp></span></dt> +<dd><p>Output all context of the onMetadata. +</p></dd> +</dl> + +<a name="gif-1"></a> +<h3 class="section">3.9 gif<span class="pull-right"><a class="anchor hidden-xs" href="#gif-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-gif-1" aria-hidden="true">TOC</a></span></h3> + +<p>Animated GIF demuxer. +</p> +<p>It accepts the following options: +</p> +<dl compact="compact"> +<dt><span><samp>min_delay</samp></span></dt> +<dd><p>Set the minimum valid delay between frames in hundredths of seconds. +Range is 0 to 6000. Default value is 2. +</p> +</dd> +<dt><span><samp>max_gif_delay</samp></span></dt> +<dd><p>Set the maximum valid delay between frames in hundredth of seconds. +Range is 0 to 65535. Default value is 65535 (nearly eleven minutes), +the maximum value allowed by the specification. +</p> +</dd> +<dt><span><samp>default_delay</samp></span></dt> +<dd><p>Set the default delay between frames in hundredths of seconds. +Range is 0 to 6000. Default value is 10. +</p> +</dd> +<dt><span><samp>ignore_loop</samp></span></dt> +<dd><p>GIF files can contain information to loop a certain number of times (or +infinitely). If <samp>ignore_loop</samp> is set to 1, then the loop setting +from the input will be ignored and looping will not occur. If set to 0, +then looping will occur and will cycle the number of times according to +the GIF. Default value is 1. +</p></dd> +</dl> + +<p>For example, with the overlay filter, place an infinitely looping GIF +over another video: +</p><div class="example"> +<pre class="example">ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv +</pre></div> + +<p>Note that in the above example the shortest option for overlay filter is +used to end the output video at the length of the shortest input file, +which in this case is <samp>input.mp4</samp> as the GIF in this example loops +infinitely. +</p> +<a name="hls-1"></a> +<h3 class="section">3.10 hls<span class="pull-right"><a class="anchor hidden-xs" href="#hls-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-hls-1" aria-hidden="true">TOC</a></span></h3> + +<p>HLS demuxer +</p> +<p>Apple HTTP Live Streaming demuxer. +</p> +<p>This demuxer presents all AVStreams from all variant streams. +The id field is set to the bitrate variant index number. By setting +the discard flags on AVStreams (by pressing ’a’ or ’v’ in ffplay), +the caller can decide which variant streams to actually receive. +The total bitrate of the variant that the stream belongs to is +available in a metadata key named "variant_bitrate". +</p> +<p>It accepts the following options: +</p> +<dl compact="compact"> +<dt><span><samp>live_start_index</samp></span></dt> +<dd><p>segment index to start live streams at (negative values are from the end). +</p> +</dd> +<dt><span><samp>prefer_x_start</samp></span></dt> +<dd><p>prefer to use #EXT-X-START if it’s in playlist instead of live_start_index. +</p> +</dd> +<dt><span><samp>allowed_extensions</samp></span></dt> +<dd><p>’,’ separated list of file extensions that hls is allowed to access. +</p> +</dd> +<dt><span><samp>max_reload</samp></span></dt> +<dd><p>Maximum number of times a insufficient list is attempted to be reloaded. +Default value is 1000. +</p> +</dd> +<dt><span><samp>m3u8_hold_counters</samp></span></dt> +<dd><p>The maximum number of times to load m3u8 when it refreshes without new segments. +Default value is 1000. +</p> +</dd> +<dt><span><samp>http_persistent</samp></span></dt> +<dd><p>Use persistent HTTP connections. Applicable only for HTTP streams. +Enabled by default. +</p> +</dd> +<dt><span><samp>http_multiple</samp></span></dt> +<dd><p>Use multiple HTTP connections for downloading HTTP segments. +Enabled by default for HTTP/1.1 servers. +</p> +</dd> +<dt><span><samp>http_seekable</samp></span></dt> +<dd><p>Use HTTP partial requests for downloading HTTP segments. +0 = disable, 1 = enable, -1 = auto, Default is auto. +</p> +</dd> +<dt><span><samp>seg_format_options</samp></span></dt> +<dd><p>Set options for the demuxer of media segments using a list of key=value pairs separated by <code>:</code>. +</p></dd> +</dl> + +<a name="image2-1"></a> +<h3 class="section">3.11 image2<span class="pull-right"><a class="anchor hidden-xs" href="#image2-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-image2-1" aria-hidden="true">TOC</a></span></h3> + +<p>Image file demuxer. +</p> +<p>This demuxer reads from a list of image files specified by a pattern. +The syntax and meaning of the pattern is specified by the +option <var>pattern_type</var>. +</p> +<p>The pattern may contain a suffix which is used to automatically +determine the format of the images contained in the files. +</p> +<p>The size, the pixel format, and the format of each image must be the +same for all the files in the sequence. +</p> +<p>This demuxer accepts the following options: +</p><dl compact="compact"> +<dt><span><samp>framerate</samp></span></dt> +<dd><p>Set the frame rate for the video stream. It defaults to 25. +</p></dd> +<dt><span><samp>loop</samp></span></dt> +<dd><p>If set to 1, loop over the input. Default value is 0. +</p></dd> +<dt><span><samp>pattern_type</samp></span></dt> +<dd><p>Select the pattern type used to interpret the provided filename. +</p> +<p><var>pattern_type</var> accepts one of the following values. +</p><dl compact="compact"> +<dt><span><samp>none</samp></span></dt> +<dd><p>Disable pattern matching, therefore the video will only contain the specified +image. You should use this option if you do not want to create sequences from +multiple images and your filenames may contain special pattern characters. +</p></dd> +<dt><span><samp>sequence</samp></span></dt> +<dd><p>Select a sequence pattern type, used to specify a sequence of files +indexed by sequential numbers. +</p> +<p>A sequence pattern may contain the string "%d" or "%0<var>N</var>d", which +specifies the position of the characters representing a sequential +number in each filename matched by the pattern. If the form +"%d0<var>N</var>d" is used, the string representing the number in each +filename is 0-padded and <var>N</var> is the total number of 0-padded +digits representing the number. The literal character ’%’ can be +specified in the pattern with the string "%%". +</p> +<p>If the sequence pattern contains "%d" or "%0<var>N</var>d", the first filename of +the file list specified by the pattern must contain a number +inclusively contained between <var>start_number</var> and +<var>start_number</var>+<var>start_number_range</var>-1, and all the following +numbers must be sequential. +</p> +<p>For example the pattern "img-%03d.bmp" will match a sequence of +filenames of the form <samp>img-001.bmp</samp>, <samp>img-002.bmp</samp>, ..., +<samp>img-010.bmp</samp>, etc.; the pattern "i%%m%%g-%d.jpg" will match a +sequence of filenames of the form <samp>i%m%g-1.jpg</samp>, +<samp>i%m%g-2.jpg</samp>, ..., <samp>i%m%g-10.jpg</samp>, etc. +</p> +<p>Note that the pattern must not necessarily contain "%d" or +"%0<var>N</var>d", for example to convert a single image file +<samp>img.jpeg</samp> you can employ the command: +</p><div class="example"> +<pre class="example">ffmpeg -i img.jpeg img.png +</pre></div> + +</dd> +<dt><span><samp>glob</samp></span></dt> +<dd><p>Select a glob wildcard pattern type. +</p> +<p>The pattern is interpreted like a <code>glob()</code> pattern. This is only +selectable if libavformat was compiled with globbing support. +</p> +</dd> +<dt><span><samp>glob_sequence <em>(deprecated, will be removed)</em></samp></span></dt> +<dd><p>Select a mixed glob wildcard/sequence pattern. +</p> +<p>If your version of libavformat was compiled with globbing support, and +the provided pattern contains at least one glob meta character among +<code>%*?[]{}</code> that is preceded by an unescaped "%", the pattern is +interpreted like a <code>glob()</code> pattern, otherwise it is interpreted +like a sequence pattern. +</p> +<p>All glob special characters <code>%*?[]{}</code> must be prefixed +with "%". To escape a literal "%" you shall use "%%". +</p> +<p>For example the pattern <code>foo-%*.jpeg</code> will match all the +filenames prefixed by "foo-" and terminating with ".jpeg", and +<code>foo-%?%?%?.jpeg</code> will match all the filenames prefixed with +"foo-", followed by a sequence of three characters, and terminating +with ".jpeg". +</p> +<p>This pattern type is deprecated in favor of <var>glob</var> and +<var>sequence</var>. +</p></dd> +</dl> + +<p>Default value is <var>glob_sequence</var>. +</p></dd> +<dt><span><samp>pixel_format</samp></span></dt> +<dd><p>Set the pixel format of the images to read. If not specified the pixel +format is guessed from the first image file in the sequence. +</p></dd> +<dt><span><samp>start_number</samp></span></dt> +<dd><p>Set the index of the file matched by the image file pattern to start +to read from. Default value is 0. +</p></dd> +<dt><span><samp>start_number_range</samp></span></dt> +<dd><p>Set the index interval range to check when looking for the first image +file in the sequence, starting from <var>start_number</var>. Default value +is 5. +</p></dd> +<dt><span><samp>ts_from_file</samp></span></dt> +<dd><p>If set to 1, will set frame timestamp to modification time of image file. Note +that monotonity of timestamps is not provided: images go in the same order as +without this option. Default value is 0. +If set to 2, will set frame timestamp to the modification time of the image file in +nanosecond precision. +</p></dd> +<dt><span><samp>video_size</samp></span></dt> +<dd><p>Set the video size of the images to read. If not specified the video +size is guessed from the first image file in the sequence. +</p></dd> +<dt><span><samp>export_path_metadata</samp></span></dt> +<dd><p>If set to 1, will add two extra fields to the metadata found in input, making them +also available for other filters (see <var>drawtext</var> filter for examples). Default +value is 0. The extra fields are described below: +</p><dl compact="compact"> +<dt><span><samp>lavf.image2dec.source_path</samp></span></dt> +<dd><p>Corresponds to the full path to the input file being read. +</p></dd> +<dt><span><samp>lavf.image2dec.source_basename</samp></span></dt> +<dd><p>Corresponds to the name of the file being read. +</p></dd> +</dl> + +</dd> +</dl> + +<a name="Examples-1"></a> +<h4 class="subsection">3.11.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-1" aria-hidden="true">TOC</a></span></h4> + +<ul> +<li> Use <code>ffmpeg</code> for creating a video from the images in the file +sequence <samp>img-001.jpeg</samp>, <samp>img-002.jpeg</samp>, ..., assuming an +input frame rate of 10 frames per second: +<div class="example"> +<pre class="example">ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv +</pre></div> + +</li><li> As above, but start by reading from a file with index 100 in the sequence: +<div class="example"> +<pre class="example">ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv +</pre></div> + +</li><li> Read images matching the "*.png" glob pattern , that is all the files +terminating with the ".png" suffix: +<div class="example"> +<pre class="example">ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv +</pre></div> +</li></ul> + +<a name="libgme"></a> +<h3 class="section">3.12 libgme<span class="pull-right"><a class="anchor hidden-xs" href="#libgme" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libgme" aria-hidden="true">TOC</a></span></h3> + +<p>The Game Music Emu library is a collection of video game music file emulators. +</p> +<p>See <a href="https://bitbucket.org/mpyne/game-music-emu/overview">https://bitbucket.org/mpyne/game-music-emu/overview</a> for more information. +</p> +<p>It accepts the following options: +</p> +<dl compact="compact"> +<dt><span><samp>track_index</samp></span></dt> +<dd><p>Set the index of which track to demux. The demuxer can only export one track. +Track indexes start at 0. Default is to pick the first track. Number of tracks +is exported as <var>tracks</var> metadata entry. +</p> +</dd> +<dt><span><samp>sample_rate</samp></span></dt> +<dd><p>Set the sampling rate of the exported track. Range is 1000 to 999999. Default is 44100. +</p> +</dd> +<dt><span><samp>max_size <em>(bytes)</em></samp></span></dt> +<dd><p>The demuxer buffers the entire file into memory. Adjust this value to set the maximum buffer size, +which in turn, acts as a ceiling for the size of files that can be read. +Default is 50 MiB. +</p> +</dd> +</dl> + +<a name="libmodplug"></a> +<h3 class="section">3.13 libmodplug<span class="pull-right"><a class="anchor hidden-xs" href="#libmodplug" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libmodplug" aria-hidden="true">TOC</a></span></h3> + +<p>ModPlug based module demuxer +</p> +<p>See <a href="https://github.com/Konstanty/libmodplug">https://github.com/Konstanty/libmodplug</a> +</p> +<p>It will export one 2-channel 16-bit 44.1 kHz audio stream. +Optionally, a <code>pal8</code> 16-color video stream can be exported with or without printed metadata. +</p> +<p>It accepts the following options: +</p> +<dl compact="compact"> +<dt><span><samp>noise_reduction</samp></span></dt> +<dd><p>Apply a simple low-pass filter. Can be 1 (on) or 0 (off). Default is 0. +</p> +</dd> +<dt><span><samp>reverb_depth</samp></span></dt> +<dd><p>Set amount of reverb. Range 0-100. Default is 0. +</p> +</dd> +<dt><span><samp>reverb_delay</samp></span></dt> +<dd><p>Set delay in ms, clamped to 40-250 ms. Default is 0. +</p> +</dd> +<dt><span><samp>bass_amount</samp></span></dt> +<dd><p>Apply bass expansion a.k.a. XBass or megabass. Range is 0 (quiet) to 100 (loud). Default is 0. +</p> +</dd> +<dt><span><samp>bass_range</samp></span></dt> +<dd><p>Set cutoff i.e. upper-bound for bass frequencies. Range is 10-100 Hz. Default is 0. +</p> +</dd> +<dt><span><samp>surround_depth</samp></span></dt> +<dd><p>Apply a Dolby Pro-Logic surround effect. Range is 0 (quiet) to 100 (heavy). Default is 0. +</p> +</dd> +<dt><span><samp>surround_delay</samp></span></dt> +<dd><p>Set surround delay in ms, clamped to 5-40 ms. Default is 0. +</p> +</dd> +<dt><span><samp>max_size</samp></span></dt> +<dd><p>The demuxer buffers the entire file into memory. Adjust this value to set the maximum buffer size, +which in turn, acts as a ceiling for the size of files that can be read. Range is 0 to 100 MiB. +0 removes buffer size limit (not recommended). Default is 5 MiB. +</p> +</dd> +<dt><span><samp>video_stream_expr</samp></span></dt> +<dd><p>String which is evaluated using the eval API to assign colors to the generated video stream. +Variables which can be used are <code>x</code>, <code>y</code>, <code>w</code>, <code>h</code>, <code>t</code>, <code>speed</code>, +<code>tempo</code>, <code>order</code>, <code>pattern</code> and <code>row</code>. +</p> +</dd> +<dt><span><samp>video_stream</samp></span></dt> +<dd><p>Generate video stream. Can be 1 (on) or 0 (off). Default is 0. +</p> +</dd> +<dt><span><samp>video_stream_w</samp></span></dt> +<dd><p>Set video frame width in ’chars’ where one char indicates 8 pixels. Range is 20-512. Default is 30. +</p> +</dd> +<dt><span><samp>video_stream_h</samp></span></dt> +<dd><p>Set video frame height in ’chars’ where one char indicates 8 pixels. Range is 20-512. Default is 30. +</p> +</dd> +<dt><span><samp>video_stream_ptxt</samp></span></dt> +<dd><p>Print metadata on video stream. Includes <code>speed</code>, <code>tempo</code>, <code>order</code>, <code>pattern</code>, +<code>row</code> and <code>ts</code> (time in ms). Can be 1 (on) or 0 (off). Default is 1. +</p> +</dd> +</dl> + +<a name="libopenmpt"></a> +<h3 class="section">3.14 libopenmpt<span class="pull-right"><a class="anchor hidden-xs" href="#libopenmpt" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libopenmpt" aria-hidden="true">TOC</a></span></h3> + +<p>libopenmpt based module demuxer +</p> +<p>See <a href="https://lib.openmpt.org/libopenmpt/">https://lib.openmpt.org/libopenmpt/</a> for more information. +</p> +<p>Some files have multiple subsongs (tracks) this can be set with the <samp>subsong</samp> +option. +</p> +<p>It accepts the following options: +</p> +<dl compact="compact"> +<dt><span><samp>subsong</samp></span></dt> +<dd><p>Set the subsong index. This can be either ’all’, ’auto’, or the index of the +subsong. Subsong indexes start at 0. The default is ’auto’. +</p> +<p>The default value is to let libopenmpt choose. +</p> +</dd> +<dt><span><samp>layout</samp></span></dt> +<dd><p>Set the channel layout. Valid values are 1, 2, and 4 channel layouts. +The default value is STEREO. +</p> +</dd> +<dt><span><samp>sample_rate</samp></span></dt> +<dd><p>Set the sample rate for libopenmpt to output. +Range is from 1000 to INT_MAX. The value default is 48000. +</p></dd> +</dl> + +<a name="mov_002fmp4_002f3gp"></a> +<h3 class="section">3.15 mov/mp4/3gp<span class="pull-right"><a class="anchor hidden-xs" href="#mov_002fmp4_002f3gp" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mov_002fmp4_002f3gp" aria-hidden="true">TOC</a></span></h3> + +<p>Demuxer for Quicktime File Format & ISO/IEC Base Media File Format (ISO/IEC 14496-12 or MPEG-4 Part 12, ISO/IEC 15444-12 or JPEG 2000 Part 12). +</p> +<p>Registered extensions: mov, mp4, m4a, 3gp, 3g2, mj2, psp, m4b, ism, ismv, isma, f4v +</p> +<a name="Options-2"></a> +<h4 class="subsection">3.15.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-2" aria-hidden="true">TOC</a></span></h4> + +<p>This demuxer accepts the following options: +</p><dl compact="compact"> +<dt><span><samp>enable_drefs</samp></span></dt> +<dd><p>Enable loading of external tracks, disabled by default. +Enabling this can theoretically leak information in some use cases. +</p> +</dd> +<dt><span><samp>use_absolute_path</samp></span></dt> +<dd><p>Allows loading of external tracks via absolute paths, disabled by default. +Enabling this poses a security risk. It should only be enabled if the source +is known to be non-malicious. +</p> +</dd> +<dt><span><samp>seek_streams_individually</samp></span></dt> +<dd><p>When seeking, identify the closest point in each stream individually and demux packets in +that stream from identified point. This can lead to a different sequence of packets compared +to demuxing linearly from the beginning. Default is true. +</p> +</dd> +<dt><span><samp>ignore_editlist</samp></span></dt> +<dd><p>Ignore any edit list atoms. The demuxer, by default, modifies the stream index to reflect the +timeline described by the edit list. Default is false. +</p> +</dd> +<dt><span><samp>advanced_editlist</samp></span></dt> +<dd><p>Modify the stream index to reflect the timeline described by the edit list. <code>ignore_editlist</code> +must be set to false for this option to be effective. +If both <code>ignore_editlist</code> and this option are set to false, then only the +start of the stream index is modified to reflect initial dwell time or starting timestamp +described by the edit list. Default is true. +</p> +</dd> +<dt><span><samp>ignore_chapters</samp></span></dt> +<dd><p>Don’t parse chapters. This includes GoPro ’HiLight’ tags/moments. Note that chapters are +only parsed when input is seekable. Default is false. +</p> +</dd> +<dt><span><samp>use_mfra_for</samp></span></dt> +<dd><p>For seekable fragmented input, set fragment’s starting timestamp from media fragment random access box, if present. +</p> +<p>Following options are available: +</p><dl compact="compact"> +<dt><span>‘<samp>auto</samp>’</span></dt> +<dd><p>Auto-detect whether to set mfra timestamps as PTS or DTS <em>(default)</em> +</p> +</dd> +<dt><span>‘<samp>dts</samp>’</span></dt> +<dd><p>Set mfra timestamps as DTS +</p> +</dd> +<dt><span>‘<samp>pts</samp>’</span></dt> +<dd><p>Set mfra timestamps as PTS +</p> +</dd> +<dt><span>‘<samp>0</samp>’</span></dt> +<dd><p>Don’t use mfra box to set timestamps +</p></dd> +</dl> + +</dd> +<dt><span><samp>use_tfdt</samp></span></dt> +<dd><p>For fragmented input, set fragment’s starting timestamp to <code>baseMediaDecodeTime</code> from the <code>tfdt</code> box. +Default is enabled, which will prefer to use the <code>tfdt</code> box to set DTS. Disable to use the <code>earliest_presentation_time</code> from the <code>sidx</code> box. +In either case, the timestamp from the <code>mfra</code> box will be used if it’s available and <code>use_mfra_for</code> is +set to pts or dts. +</p> +</dd> +<dt><span><samp>export_all</samp></span></dt> +<dd><p>Export unrecognized boxes within the <var>udta</var> box as metadata entries. The first four +characters of the box type are set as the key. Default is false. +</p> +</dd> +<dt><span><samp>export_xmp</samp></span></dt> +<dd><p>Export entire contents of <var>XMP_</var> box and <var>uuid</var> box as a string with key <code>xmp</code>. Note that +if <code>export_all</code> is set and this option isn’t, the contents of <var>XMP_</var> box are still exported +but with key <code>XMP_</code>. Default is false. +</p> +</dd> +<dt><span><samp>activation_bytes</samp></span></dt> +<dd><p>4-byte key required to decrypt Audible AAX and AAX+ files. See Audible AAX subsection below. +</p> +</dd> +<dt><span><samp>audible_fixed_key</samp></span></dt> +<dd><p>Fixed key used for handling Audible AAX/AAX+ files. It has been pre-set so should not be necessary to +specify. +</p> +</dd> +<dt><span><samp>decryption_key</samp></span></dt> +<dd><p>16-byte key, in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR; ISO/IEC 23001-7). +</p> +</dd> +<dt><span><samp>max_stts_delta</samp></span></dt> +<dd><p>Very high sample deltas written in a trak’s stts box may occasionally be intended but usually they are written in +error or used to store a negative value for dts correction when treated as signed 32-bit integers. This option lets +the user set an upper limit, beyond which the delta is clamped to 1. Values greater than the limit if negative when +cast to int32 are used to adjust onward dts. +</p> +<p>Unit is the track time scale. Range is 0 to UINT_MAX. Default is <code>UINT_MAX - 48000*10</code> which allows upto +a 10 second dts correction for 48 kHz audio streams while accommodating 99.9% of <code>uint32</code> range. +</p></dd> +</dl> + +<a name="Audible-AAX"></a> +<h4 class="subsection">3.15.2 Audible AAX<span class="pull-right"><a class="anchor hidden-xs" href="#Audible-AAX" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Audible-AAX" aria-hidden="true">TOC</a></span></h4> + +<p>Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation secret. +</p><div class="example"> +<pre class="example">ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4 +</pre></div> + +<a name="mpegts"></a> +<h3 class="section">3.16 mpegts<span class="pull-right"><a class="anchor hidden-xs" href="#mpegts" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mpegts" aria-hidden="true">TOC</a></span></h3> + +<p>MPEG-2 transport stream demuxer. +</p> +<p>This demuxer accepts the following options: +</p><dl compact="compact"> +<dt><span><samp>resync_size</samp></span></dt> +<dd><p>Set size limit for looking up a new synchronization. Default value is +65536. +</p> +</dd> +<dt><span><samp>skip_unknown_pmt</samp></span></dt> +<dd><p>Skip PMTs for programs not defined in the PAT. Default value is 0. +</p> +</dd> +<dt><span><samp>fix_teletext_pts</samp></span></dt> +<dd><p>Override teletext packet PTS and DTS values with the timestamps calculated +from the PCR of the first program which the teletext stream is part of and is +not discarded. Default value is 1, set this option to 0 if you want your +teletext packet PTS and DTS values untouched. +</p> +</dd> +<dt><span><samp>ts_packetsize</samp></span></dt> +<dd><p>Output option carrying the raw packet size in bytes. +Show the detected raw packet size, cannot be set by the user. +</p> +</dd> +<dt><span><samp>scan_all_pmts</samp></span></dt> +<dd><p>Scan and combine all PMTs. The value is an integer with value from -1 +to 1 (-1 means automatic setting, 1 means enabled, 0 means +disabled). Default value is -1. +</p> +</dd> +<dt><span><samp>merge_pmt_versions</samp></span></dt> +<dd><p>Re-use existing streams when a PMT’s version is updated and elementary +streams move to different PIDs. Default value is 0. +</p> +</dd> +<dt><span><samp>max_packet_size</samp></span></dt> +<dd><p>Set maximum size, in bytes, of packet emitted by the demuxer. Payloads above this size +are split across multiple packets. Range is 1 to INT_MAX/2. Default is 204800 bytes. +</p></dd> +</dl> + +<a name="mpjpeg"></a> +<h3 class="section">3.17 mpjpeg<span class="pull-right"><a class="anchor hidden-xs" href="#mpjpeg" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mpjpeg" aria-hidden="true">TOC</a></span></h3> + +<p>MJPEG encapsulated in multi-part MIME demuxer. +</p> +<p>This demuxer allows reading of MJPEG, where each frame is represented as a part of +multipart/x-mixed-replace stream. +</p><dl compact="compact"> +<dt><span><samp>strict_mime_boundary</samp></span></dt> +<dd><p>Default implementation applies a relaxed standard to multi-part MIME boundary detection, +to prevent regression with numerous existing endpoints not generating a proper MIME +MJPEG stream. Turning this option on by setting it to 1 will result in a stricter check +of the boundary value. +</p></dd> +</dl> + +<a name="rawvideo"></a> +<h3 class="section">3.18 rawvideo<span class="pull-right"><a class="anchor hidden-xs" href="#rawvideo" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-rawvideo" aria-hidden="true">TOC</a></span></h3> + +<p>Raw video demuxer. +</p> +<p>This demuxer allows one to read raw video data. Since there is no header +specifying the assumed video parameters, the user must specify them +in order to be able to decode the data correctly. +</p> +<p>This demuxer accepts the following options: +</p><dl compact="compact"> +<dt><span><samp>framerate</samp></span></dt> +<dd><p>Set input video frame rate. Default value is 25. +</p> +</dd> +<dt><span><samp>pixel_format</samp></span></dt> +<dd><p>Set the input video pixel format. Default value is <code>yuv420p</code>. +</p> +</dd> +<dt><span><samp>video_size</samp></span></dt> +<dd><p>Set the input video size. This value must be specified explicitly. +</p></dd> +</dl> + +<p>For example to read a rawvideo file <samp>input.raw</samp> with +<code>ffplay</code>, assuming a pixel format of <code>rgb24</code>, a video +size of <code>320x240</code>, and a frame rate of 10 images per second, use +the command: +</p><div class="example"> +<pre class="example">ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw +</pre></div> + +<a name="sbg"></a> +<h3 class="section">3.19 sbg<span class="pull-right"><a class="anchor hidden-xs" href="#sbg" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-sbg" aria-hidden="true">TOC</a></span></h3> + +<p>SBaGen script demuxer. +</p> +<p>This demuxer reads the script language used by SBaGen +<a href="http://uazu.net/sbagen/">http://uazu.net/sbagen/</a> to generate binaural beats sessions. A SBG +script looks like that: +</p><div class="example"> +<pre class="example">-SE +a: 300-2.5/3 440+4.5/0 +b: 300-2.5/0 440+4.5/3 +off: - +NOW == a ++0:07:00 == b ++0:14:00 == a ++0:21:00 == b ++0:30:00 off +</pre></div> + +<p>A SBG script can mix absolute and relative timestamps. If the script uses +either only absolute timestamps (including the script start time) or only +relative ones, then its layout is fixed, and the conversion is +straightforward. On the other hand, if the script mixes both kind of +timestamps, then the <var>NOW</var> reference for relative timestamps will be +taken from the current time of day at the time the script is read, and the +script layout will be frozen according to that reference. That means that if +the script is directly played, the actual times will match the absolute +timestamps up to the sound controller’s clock accuracy, but if the user +somehow pauses the playback or seeks, all times will be shifted accordingly. +</p> +<a name="tedcaptions"></a> +<h3 class="section">3.20 tedcaptions<span class="pull-right"><a class="anchor hidden-xs" href="#tedcaptions" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-tedcaptions" aria-hidden="true">TOC</a></span></h3> + +<p>JSON captions used for <a href="http://www.ted.com/">TED Talks</a>. +</p> +<p>TED does not provide links to the captions, but they can be guessed from the +page. The file <samp>tools/bookmarklets.html</samp> from the FFmpeg source tree +contains a bookmarklet to expose them. +</p> +<p>This demuxer accepts the following option: +</p><dl compact="compact"> +<dt><span><samp>start_time</samp></span></dt> +<dd><p>Set the start time of the TED talk, in milliseconds. The default is 15000 +(15s). It is used to sync the captions with the downloadable videos, because +they include a 15s intro. +</p></dd> +</dl> + +<p>Example: convert the captions to a format most players understand: +</p><div class="example"> +<pre class="example">ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt +</pre></div> + +<a name="vapoursynth"></a> +<h3 class="section">3.21 vapoursynth<span class="pull-right"><a class="anchor hidden-xs" href="#vapoursynth" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-vapoursynth" aria-hidden="true">TOC</a></span></h3> + +<p>Vapoursynth wrapper. +</p> +<p>Due to security concerns, Vapoursynth scripts will not +be autodetected so the input format has to be forced. For ff* CLI tools, +add <code>-f vapoursynth</code> before the input <code>-i yourscript.vpy</code>. +</p> +<p>This demuxer accepts the following option: +</p><dl compact="compact"> +<dt><span><samp>max_script_size</samp></span></dt> +<dd><p>The demuxer buffers the entire script into memory. Adjust this value to set the maximum buffer size, +which in turn, acts as a ceiling for the size of scripts that can be read. +Default is 1 MiB. +</p></dd> +</dl> + +<a name="Muxers"></a> +<h2 class="chapter">4 Muxers<span class="pull-right"><a class="anchor hidden-xs" href="#Muxers" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Muxers" aria-hidden="true">TOC</a></span></h2> + +<p>Muxers are configured elements in FFmpeg which allow writing +multimedia streams to a particular type of file. +</p> +<p>When you configure your FFmpeg build, all the supported muxers +are enabled by default. You can list all available muxers using the +configure option <code>--list-muxers</code>. +</p> +<p>You can disable all the muxers with the configure option +<code>--disable-muxers</code> and selectively enable / disable single muxers +with the options <code>--enable-muxer=<var>MUXER</var></code> / +<code>--disable-muxer=<var>MUXER</var></code>. +</p> +<p>The option <code>-muxers</code> of the ff* tools will display the list of +enabled muxers. Use <code>-formats</code> to view a combined list of +enabled demuxers and muxers. +</p> +<p>A description of some of the currently available muxers follows. +</p> +<span id="a64"></span><a name="a64-1"></a> +<h3 class="section">4.1 a64<span class="pull-right"><a class="anchor hidden-xs" href="#a64-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-a64-1" aria-hidden="true">TOC</a></span></h3> + +<p>A64 muxer for Commodore 64 video. Accepts a single <code>a64_multi</code> or <code>a64_multi5</code> codec video stream. +</p> +<span id="adts"></span><a name="adts-1"></a> +<h3 class="section">4.2 adts<span class="pull-right"><a class="anchor hidden-xs" href="#adts-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-adts-1" aria-hidden="true">TOC</a></span></h3> + +<p>Audio Data Transport Stream muxer. It accepts a single AAC stream. +</p> +<a name="Options-3"></a> +<h4 class="subsection">4.2.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-3" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-3" aria-hidden="true">TOC</a></span></h4> + +<p>It accepts the following options: +</p> +<dl compact="compact"> +<dt><span><samp>write_id3v2 <var>bool</var></samp></span></dt> +<dd><p>Enable to write ID3v2.4 tags at the start of the stream. Default is disabled. +</p> +</dd> +<dt><span><samp>write_apetag <var>bool</var></samp></span></dt> +<dd><p>Enable to write APE tags at the end of the stream. Default is disabled. +</p> +</dd> +<dt><span><samp>write_mpeg2 <var>bool</var></samp></span></dt> +<dd><p>Enable to set MPEG version bit in the ADTS frame header to 1 which indicates MPEG-2. Default is 0, which indicates MPEG-4. +</p> +</dd> +</dl> + +<span id="aiff"></span><a name="aiff-1"></a> +<h3 class="section">4.3 aiff<span class="pull-right"><a class="anchor hidden-xs" href="#aiff-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-aiff-1" aria-hidden="true">TOC</a></span></h3> + +<p>Audio Interchange File Format muxer. +</p> +<a name="Options-4"></a> +<h4 class="subsection">4.3.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-4" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-4" aria-hidden="true">TOC</a></span></h4> + +<p>It accepts the following options: +</p> +<dl compact="compact"> +<dt><span><samp>write_id3v2</samp></span></dt> +<dd><p>Enable ID3v2 tags writing when set to 1. Default is 0 (disabled). +</p> +</dd> +<dt><span><samp>id3v2_version</samp></span></dt> +<dd><p>Select ID3v2 version to write. Currently only version 3 and 4 (aka. +ID3v2.3 and ID3v2.4) are supported. The default is version 4. +</p> +</dd> +</dl> + +<span id="alp"></span><a name="alp-1"></a> +<h3 class="section">4.4 alp<span class="pull-right"><a class="anchor hidden-xs" href="#alp-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-alp-1" aria-hidden="true">TOC</a></span></h3> + +<p>Muxer for audio of High Voltage Software’s Lego Racers game. It accepts a single ADPCM_IMA_ALP stream +with no more than 2 channels nor a sample rate greater than 44100 Hz. +</p> +<p>Extensions: tun, pcm +</p> +<a name="Options-5"></a> +<h4 class="subsection">4.4.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-5" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-5" aria-hidden="true">TOC</a></span></h4> + +<p>It accepts the following options: +</p> +<dl compact="compact"> +<dt><span><samp>type <var>type</var></samp></span></dt> +<dd><p>Set file type. +</p> +<dl compact="compact"> +<dt><span>‘<samp>tun</samp>’</span></dt> +<dd><p>Set file type as music. Must have a sample rate of 22050 Hz. +</p> +</dd> +<dt><span>‘<samp>pcm</samp>’</span></dt> +<dd><p>Set file type as sfx. +</p> +</dd> +<dt><span>‘<samp>auto</samp>’</span></dt> +<dd><p>Set file type as per output file extension. <code>.pcm</code> results in type <code>pcm</code> else type <code>tun</code> is set. <var>(default)</var> +</p> +</dd> +</dl> + +</dd> +</dl> + +<span id="asf"></span><a name="asf-2"></a> +<h3 class="section">4.5 asf<span class="pull-right"><a class="anchor hidden-xs" href="#asf-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-asf-2" aria-hidden="true">TOC</a></span></h3> + +<p>Advanced Systems Format muxer. +</p> +<p>Note that Windows Media Audio (wma) and Windows Media Video (wmv) use this +muxer too. +</p> +<a name="Options-6"></a> +<h4 class="subsection">4.5.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-6" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-6" aria-hidden="true">TOC</a></span></h4> + +<p>It accepts the following options: +</p> +<dl compact="compact"> +<dt><span><samp>packet_size</samp></span></dt> +<dd><p>Set the muxer packet size. By tuning this setting you may reduce data +fragmentation or muxer overhead depending on your source. Default value is +3200, minimum is 100, maximum is 64k. +</p> +</dd> +</dl> + +<span id="avi"></span><a name="avi-1"></a> +<h3 class="section">4.6 avi<span class="pull-right"><a class="anchor hidden-xs" href="#avi-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-avi-1" aria-hidden="true">TOC</a></span></h3> + +<p>Audio Video Interleaved muxer. +</p> +<a name="Options-7"></a> +<h4 class="subsection">4.6.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-7" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-7" aria-hidden="true">TOC</a></span></h4> + +<p>It accepts the following options: +</p> +<dl compact="compact"> +<dt><span><samp>reserve_index_space</samp></span></dt> +<dd><p>Reserve the specified amount of bytes for the OpenDML master index of each +stream within the file header. By default additional master indexes are +embedded within the data packets if there is no space left in the first master +index and are linked together as a chain of indexes. This index structure can +cause problems for some use cases, e.g. third-party software strictly relying +on the OpenDML index specification or when file seeking is slow. Reserving +enough index space in the file header avoids these problems. +</p> +<p>The required index space depends on the output file size and should be about 16 +bytes per gigabyte. When this option is omitted or set to zero the necessary +index space is guessed. +</p> +</dd> +<dt><span><samp>write_channel_mask</samp></span></dt> +<dd><p>Write the channel layout mask into the audio stream header. +</p> +<p>This option is enabled by default. Disabling the channel mask can be useful in +specific scenarios, e.g. when merging multiple audio streams into one for +compatibility with software that only supports a single audio stream in AVI +(see <a data-manual="ffmpeg-filters" href="ffmpeg-filters.html#amerge">(ffmpeg-filters)the "amerge" section in the ffmpeg-filters manual</a>). +</p> +</dd> +<dt><span><samp>flipped_raw_rgb</samp></span></dt> +<dd><p>If set to true, store positive height for raw RGB bitmaps, which indicates +bitmap is stored bottom-up. Note that this option does not flip the bitmap +which has to be done manually beforehand, e.g. by using the vflip filter. +Default is <var>false</var> and indicates bitmap is stored top down. +</p> +</dd> +</dl> + +<span id="chromaprint"></span><a name="chromaprint-1"></a> +<h3 class="section">4.7 chromaprint<span class="pull-right"><a class="anchor hidden-xs" href="#chromaprint-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-chromaprint-1" aria-hidden="true">TOC</a></span></h3> + +<p>Chromaprint fingerprinter. +</p> +<p>This muxer feeds audio data to the Chromaprint library, +which generates a fingerprint for the provided audio data. See <a href="https://acoustid.org/chromaprint">https://acoustid.org/chromaprint</a> +</p> +<p>It takes a single signed native-endian 16-bit raw audio stream of at most 2 channels. +</p> +<a name="Options-8"></a> +<h4 class="subsection">4.7.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-8" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-8" aria-hidden="true">TOC</a></span></h4> + +<dl compact="compact"> +<dt><span><samp>silence_threshold</samp></span></dt> +<dd><p>Threshold for detecting silence. Range is from -1 to 32767, where -1 disables +silence detection. Silence detection can only be used with version 3 of the +algorithm. +Silence detection must be disabled for use with the AcoustID service. Default is -1. +</p> +</dd> +<dt><span><samp>algorithm</samp></span></dt> +<dd><p>Version of algorithm to fingerprint with. Range is 0 to 4. +Version 3 enables silence detection. Default is 1. +</p> +</dd> +<dt><span><samp>fp_format</samp></span></dt> +<dd><p>Format to output the fingerprint as. Accepts the following options: +</p><dl compact="compact"> +<dt><span>‘<samp>raw</samp>’</span></dt> +<dd><p>Binary raw fingerprint +</p> +</dd> +<dt><span>‘<samp>compressed</samp>’</span></dt> +<dd><p>Binary compressed fingerprint +</p> +</dd> +<dt><span>‘<samp>base64</samp>’</span></dt> +<dd><p>Base64 compressed fingerprint <em>(default)</em> +</p> +</dd> +</dl> + +</dd> +</dl> + +<span id="crc"></span><a name="crc-1"></a> +<h3 class="section">4.8 crc<span class="pull-right"><a class="anchor hidden-xs" href="#crc-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-crc-1" aria-hidden="true">TOC</a></span></h3> + +<p>CRC (Cyclic Redundancy Check) testing format. +</p> +<p>This muxer computes and prints the Adler-32 CRC of all the input audio +and video frames. By default audio frames are converted to signed +16-bit raw audio and video frames to raw video before computing the +CRC. +</p> +<p>The output of the muxer consists of a single line of the form: +CRC=0x<var>CRC</var>, where <var>CRC</var> is a hexadecimal number 0-padded to +8 digits containing the CRC for all the decoded input frames. +</p> +<p>See also the <a href="#framecrc">framecrc</a> muxer. +</p> +<a name="Examples-2"></a> +<h4 class="subsection">4.8.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-2" aria-hidden="true">TOC</a></span></h4> + +<p>For example to compute the CRC of the input, and store it in the file +<samp>out.crc</samp>: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f crc out.crc +</pre></div> + +<p>You can print the CRC to stdout with the command: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f crc - +</pre></div> + +<p>You can select the output format of each frame with <code>ffmpeg</code> by +specifying the audio and video codec and format. For example to +compute the CRC of the input audio converted to PCM unsigned 8-bit +and the input video converted to MPEG-2 video, use the command: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc - +</pre></div> + +<span id="dash"></span><a name="dash-2"></a> +<h3 class="section">4.9 dash<span class="pull-right"><a class="anchor hidden-xs" href="#dash-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-dash-2" aria-hidden="true">TOC</a></span></h3> + +<p>Dynamic Adaptive Streaming over HTTP (DASH) muxer that creates segments +and manifest files according to the MPEG-DASH standard ISO/IEC 23009-1:2014. +</p> +<p>For more information see: +</p> +<ul> +<li> ISO DASH Specification: <a href="http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip">http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip</a> +</li><li> WebM DASH Specification: <a href="https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification">https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification</a> +</li></ul> + +<p>It creates a MPD manifest file and segment files for each stream. +</p> +<p>The segment filename might contain pre-defined identifiers used with SegmentTemplate +as defined in section 5.3.9.4.4 of the standard. Available identifiers are "$RepresentationID$", +"$Number$", "$Bandwidth$" and "$Time$". +In addition to the standard identifiers, an ffmpeg-specific "$ext$" identifier is also supported. +When specified ffmpeg will replace $ext$ in the file name with muxing format’s extensions such as mp4, webm etc., +</p> +<div class="example"> +<pre class="example">ffmpeg -re -i <input> -map 0 -map 0 -c:a libfdk_aac -c:v libx264 \ +-b:v:0 800k -b:v:1 300k -s:v:1 320x170 -profile:v:1 baseline \ +-profile:v:0 main -bf 1 -keyint_min 120 -g 120 -sc_threshold 0 \ +-b_strategy 0 -ar:a:1 22050 -use_timeline 1 -use_template 1 \ +-window_size 5 -adaptation_sets "id=0,streams=v id=1,streams=a" \ +-f dash /path/to/out.mpd +</pre></div> + +<dl compact="compact"> +<dt><span><samp>seg_duration <var>duration</var></samp></span></dt> +<dd><p>Set the segment length in seconds (fractional value can be set). The value is +treated as average segment duration when <var>use_template</var> is enabled and +<var>use_timeline</var> is disabled and as minimum segment duration for all the other +use cases. +</p></dd> +<dt><span><samp>frag_duration <var>duration</var></samp></span></dt> +<dd><p>Set the length in seconds of fragments within segments (fractional value can be set). +</p></dd> +<dt><span><samp>frag_type <var>type</var></samp></span></dt> +<dd><p>Set the type of interval for fragmentation. +</p></dd> +<dt><span><samp>window_size <var>size</var></samp></span></dt> +<dd><p>Set the maximum number of segments kept in the manifest. +</p></dd> +<dt><span><samp>extra_window_size <var>size</var></samp></span></dt> +<dd><p>Set the maximum number of segments kept outside of the manifest before removing from disk. +</p></dd> +<dt><span><samp>remove_at_exit <var>remove</var></samp></span></dt> +<dd><p>Enable (1) or disable (0) removal of all segments when finished. +</p></dd> +<dt><span><samp>use_template <var>template</var></samp></span></dt> +<dd><p>Enable (1) or disable (0) use of SegmentTemplate instead of SegmentList. +</p></dd> +<dt><span><samp>use_timeline <var>timeline</var></samp></span></dt> +<dd><p>Enable (1) or disable (0) use of SegmentTimeline in SegmentTemplate. +</p></dd> +<dt><span><samp>single_file <var>single_file</var></samp></span></dt> +<dd><p>Enable (1) or disable (0) storing all segments in one file, accessed using byte ranges. +</p></dd> +<dt><span><samp>single_file_name <var>file_name</var></samp></span></dt> +<dd><p>DASH-templated name to be used for baseURL. Implies <var>single_file</var> set to "1". In the template, "$ext$" is replaced with the file name extension specific for the segment format. +</p></dd> +<dt><span><samp>init_seg_name <var>init_name</var></samp></span></dt> +<dd><p>DASH-templated name to used for the initialization segment. Default is "init-stream$RepresentationID$.$ext$". "$ext$" is replaced with the file name extension specific for the segment format. +</p></dd> +<dt><span><samp>media_seg_name <var>segment_name</var></samp></span></dt> +<dd><p>DASH-templated name to used for the media segments. Default is "chunk-stream$RepresentationID$-$Number%05d$.$ext$". "$ext$" is replaced with the file name extension specific for the segment format. +</p></dd> +<dt><span><samp>utc_timing_url <var>utc_url</var></samp></span></dt> +<dd><p>URL of the page that will return the UTC timestamp in ISO format. Example: "https://time.akamai.com/?iso" +</p></dd> +<dt><span><samp>method <var>method</var></samp></span></dt> +<dd><p>Use the given HTTP method to create output files. Generally set to PUT or POST. +</p></dd> +<dt><span><samp>http_user_agent <var>user_agent</var></samp></span></dt> +<dd><p>Override User-Agent field in HTTP header. Applicable only for HTTP output. +</p></dd> +<dt><span><samp>http_persistent <var>http_persistent</var></samp></span></dt> +<dd><p>Use persistent HTTP connections. Applicable only for HTTP output. +</p></dd> +<dt><span><samp>hls_playlist <var>hls_playlist</var></samp></span></dt> +<dd><p>Generate HLS playlist files as well. The master playlist is generated with the filename <var>hls_master_name</var>. +One media playlist file is generated for each stream with filenames media_0.m3u8, media_1.m3u8, etc. +</p></dd> +<dt><span><samp>hls_master_name <var>file_name</var></samp></span></dt> +<dd><p>HLS master playlist name. Default is "master.m3u8". +</p></dd> +<dt><span><samp>streaming <var>streaming</var></samp></span></dt> +<dd><p>Enable (1) or disable (0) chunk streaming mode of output. In chunk streaming +mode, each frame will be a moof fragment which forms a chunk. +</p></dd> +<dt><span><samp>adaptation_sets <var>adaptation_sets</var></samp></span></dt> +<dd><p>Assign streams to AdaptationSets. Syntax is "id=x,streams=a,b,c id=y,streams=d,e" with x and y being the IDs +of the adaptation sets and a,b,c,d and e are the indices of the mapped streams. +</p> +<p>To map all video (or audio) streams to an AdaptationSet, "v" (or "a") can be used as stream identifier instead of IDs. +</p> +<p>When no assignment is defined, this defaults to an AdaptationSet for each stream. +</p> +<p>Optional syntax is "id=x,seg_duration=x,frag_duration=x,frag_type=type,descriptor=descriptor_string,streams=a,b,c id=y,seg_duration=y,frag_type=type,streams=d,e" and so on, +descriptor is useful to the scheme defined by ISO/IEC 23009-1:2014/Amd.2:2015. +For example, -adaptation_sets "id=0,descriptor=<SupplementalProperty schemeIdUri=\"urn:mpeg:dash:srd:2014\" value=\"0,0,0,1,1,2,2\"/>,streams=v". +Please note that descriptor string should be a self-closing xml tag. +seg_duration, frag_duration and frag_type override the global option values for each adaptation set. +For example, -adaptation_sets "id=0,seg_duration=2,frag_duration=1,frag_type=duration,streams=v id=1,seg_duration=2,frag_type=none,streams=a" +type_id marks an adaptation set as containing streams meant to be used for Trick Mode for the referenced adaptation set. +For example, -adaptation_sets "id=0,seg_duration=2,frag_type=none,streams=0 id=1,seg_duration=10,frag_type=none,trick_id=0,streams=1" +</p></dd> +<dt><span><samp>timeout <var>timeout</var></samp></span></dt> +<dd><p>Set timeout for socket I/O operations. Applicable only for HTTP output. +</p></dd> +<dt><span><samp>index_correction <var>index_correction</var></samp></span></dt> +<dd><p>Enable (1) or Disable (0) segment index correction logic. Applicable only when +<var>use_template</var> is enabled and <var>use_timeline</var> is disabled. +</p> +<p>When enabled, the logic monitors the flow of segment indexes. If a streams’s +segment index value is not at the expected real time position, then the logic +corrects that index value. +</p> +<p>Typically this logic is needed in live streaming use cases. The network bandwidth +fluctuations are common during long run streaming. Each fluctuation can cause +the segment indexes fall behind the expected real time position. +</p></dd> +<dt><span><samp>format_options <var>options_list</var></samp></span></dt> +<dd><p>Set container format (mp4/webm) options using a <code>:</code> separated list of +key=value parameters. Values containing <code>:</code> special characters must be +escaped. +</p> +</dd> +<dt><span><samp>global_sidx <var>global_sidx</var></samp></span></dt> +<dd><p>Write global SIDX atom. Applicable only for single file, mp4 output, non-streaming mode. +</p> +</dd> +<dt><span><samp>dash_segment_type <var>dash_segment_type</var></samp></span></dt> +<dd><p>Possible values: +</p><dl compact="compact"> +<dt><span><samp>auto</samp></span></dt> +<dd><p>If this flag is set, the dash segment files format will be selected based on the stream codec. This is the default mode. +</p> +</dd> +<dt><span><samp>mp4</samp></span></dt> +<dd><p>If this flag is set, the dash segment files will be in in ISOBMFF format. +</p> +</dd> +<dt><span><samp>webm</samp></span></dt> +<dd><p>If this flag is set, the dash segment files will be in in WebM format. +</p></dd> +</dl> + +</dd> +<dt><span><samp>ignore_io_errors <var>ignore_io_errors</var></samp></span></dt> +<dd><p>Ignore IO errors during open and write. Useful for long-duration runs with network output. +</p> +</dd> +<dt><span><samp>lhls <var>lhls</var></samp></span></dt> +<dd><p>Enable Low-latency HLS(LHLS). Adds #EXT-X-PREFETCH tag with current segment’s URI. +hls.js player folks are trying to standardize an open LHLS spec. The draft spec is available in https://github.com/video-dev/hlsjs-rfcs/blob/lhls-spec/proposals/0001-lhls.md +This option tries to comply with the above open spec. +It enables <var>streaming</var> and <var>hls_playlist</var> options automatically. +This is an experimental feature. +</p> +<p>Note: This is not Apple’s version LHLS. See <a href="https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis">https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis</a> +</p> +</dd> +<dt><span><samp>ldash <var>ldash</var></samp></span></dt> +<dd><p>Enable Low-latency Dash by constraining the presence and values of some elements. +</p> +</dd> +<dt><span><samp>master_m3u8_publish_rate <var>master_m3u8_publish_rate</var></samp></span></dt> +<dd><p>Publish master playlist repeatedly every after specified number of segment intervals. +</p> +</dd> +<dt><span><samp>write_prft <var>write_prft</var></samp></span></dt> +<dd><p>Write Producer Reference Time elements on supported streams. This also enables writing +prft boxes in the underlying muxer. Applicable only when the <var>utc_url</var> option is enabled. +It’s set to auto by default, in which case the muxer will attempt to enable it only in modes +that require it. +</p> +</dd> +<dt><span><samp>mpd_profile <var>mpd_profile</var></samp></span></dt> +<dd><p>Set one or more manifest profiles. +</p> +</dd> +<dt><span><samp>http_opts <var>http_opts</var></samp></span></dt> +<dd><p>A :-separated list of key=value options to pass to the underlying HTTP +protocol. Applicable only for HTTP output. +</p> +</dd> +<dt><span><samp>target_latency <var>target_latency</var></samp></span></dt> +<dd><p>Set an intended target latency in seconds (fractional value can be set) for serving. Applicable only when <var>streaming</var> and <var>write_prft</var> options are enabled. +This is an informative fields clients can use to measure the latency of the service. +</p> +</dd> +<dt><span><samp>min_playback_rate <var>min_playback_rate</var></samp></span></dt> +<dd><p>Set the minimum playback rate indicated as appropriate for the purposes of automatically +adjusting playback latency and buffer occupancy during normal playback by clients. +</p> +</dd> +<dt><span><samp>max_playback_rate <var>max_playback_rate</var></samp></span></dt> +<dd><p>Set the maximum playback rate indicated as appropriate for the purposes of automatically +adjusting playback latency and buffer occupancy during normal playback by clients. +</p> +</dd> +<dt><span><samp>update_period <var>update_period</var></samp></span></dt> +<dd><p>Set the mpd update period ,for dynamic content. + The unit is second. +</p> +</dd> +</dl> + +<span id="fifo"></span><a name="fifo-1"></a> +<h3 class="section">4.10 fifo<span class="pull-right"><a class="anchor hidden-xs" href="#fifo-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-fifo-1" aria-hidden="true">TOC</a></span></h3> + +<p>The fifo pseudo-muxer allows the separation of encoding and muxing by using +first-in-first-out queue and running the actual muxer in a separate thread. This +is especially useful in combination with the <a href="#tee">tee</a> muxer and can be used to +send data to several destinations with different reliability/writing speed/latency. +</p> +<p>API users should be aware that callback functions (interrupt_callback, +io_open and io_close) used within its AVFormatContext must be thread-safe. +</p> +<p>The behavior of the fifo muxer if the queue fills up or if the output fails is +selectable, +</p> +<ul> +<li> output can be transparently restarted with configurable delay between retries +based on real time or time of the processed stream. + +</li><li> encoding can be blocked during temporary failure, or continue transparently +dropping packets in case fifo queue fills up. + +</li></ul> + +<dl compact="compact"> +<dt><span><samp>fifo_format</samp></span></dt> +<dd><p>Specify the format name. Useful if it cannot be guessed from the +output name suffix. +</p> +</dd> +<dt><span><samp>queue_size</samp></span></dt> +<dd><p>Specify size of the queue (number of packets). Default value is 60. +</p> +</dd> +<dt><span><samp>format_opts</samp></span></dt> +<dd><p>Specify format options for the underlying muxer. Muxer options can be specified +as a list of <var>key</var>=<var>value</var> pairs separated by ’:’. +</p> +</dd> +<dt><span><samp>drop_pkts_on_overflow <var>bool</var></samp></span></dt> +<dd><p>If set to 1 (true), in case the fifo queue fills up, packets will be dropped +rather than blocking the encoder. This makes it possible to continue streaming without +delaying the input, at the cost of omitting part of the stream. By default +this option is set to 0 (false), so in such cases the encoder will be blocked +until the muxer processes some of the packets and none of them is lost. +</p> +</dd> +<dt><span><samp>attempt_recovery <var>bool</var></samp></span></dt> +<dd><p>If failure occurs, attempt to recover the output. This is especially useful +when used with network output, since it makes it possible to restart streaming transparently. +By default this option is set to 0 (false). +</p> +</dd> +<dt><span><samp>max_recovery_attempts</samp></span></dt> +<dd><p>Sets maximum number of successive unsuccessful recovery attempts after which +the output fails permanently. By default this option is set to 0 (unlimited). +</p> +</dd> +<dt><span><samp>recovery_wait_time <var>duration</var></samp></span></dt> +<dd><p>Waiting time before the next recovery attempt after previous unsuccessful +recovery attempt. Default value is 5 seconds. +</p> +</dd> +<dt><span><samp>recovery_wait_streamtime <var>bool</var></samp></span></dt> +<dd><p>If set to 0 (false), the real time is used when waiting for the recovery +attempt (i.e. the recovery will be attempted after at least +recovery_wait_time seconds). +If set to 1 (true), the time of the processed stream is taken into account +instead (i.e. the recovery will be attempted after at least <var>recovery_wait_time</var> +seconds of the stream is omitted). +By default, this option is set to 0 (false). +</p> +</dd> +<dt><span><samp>recover_any_error <var>bool</var></samp></span></dt> +<dd><p>If set to 1 (true), recovery will be attempted regardless of type of the error +causing the failure. By default this option is set to 0 (false) and in case of +certain (usually permanent) errors the recovery is not attempted even when +<var>attempt_recovery</var> is set to 1. +</p> +</dd> +<dt><span><samp>restart_with_keyframe <var>bool</var></samp></span></dt> +<dd><p>Specify whether to wait for the keyframe after recovering from +queue overflow or failure. This option is set to 0 (false) by default. +</p> +</dd> +<dt><span><samp>timeshift <var>duration</var></samp></span></dt> +<dd><p>Buffer the specified amount of packets and delay writing the output. Note that +<var>queue_size</var> must be big enough to store the packets for timeshift. At the +end of the input the fifo buffer is flushed at realtime speed. +</p> +</dd> +</dl> + +<a name="Examples-3"></a> +<h4 class="subsection">4.10.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-3" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-3" aria-hidden="true">TOC</a></span></h4> + +<ul> +<li> Stream something to rtmp server, continue processing the stream at real-time +rate even in case of temporary failure (network outage) and attempt to recover +streaming every second indefinitely. +<div class="example"> +<pre class="example">ffmpeg -re -i ... -c:v libx264 -c:a aac -f fifo -fifo_format flv -map 0:v -map 0:a + -drop_pkts_on_overflow 1 -attempt_recovery 1 -recovery_wait_time 1 rtmp://example.com/live/stream_name +</pre></div> + +</li></ul> + +<a name="flv"></a> +<h3 class="section">4.11 flv<span class="pull-right"><a class="anchor hidden-xs" href="#flv" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-flv" aria-hidden="true">TOC</a></span></h3> + +<p>Adobe Flash Video Format muxer. +</p> +<p>This muxer accepts the following options: +</p> +<dl compact="compact"> +<dt><span><samp>flvflags <var>flags</var></samp></span></dt> +<dd><p>Possible values: +</p> +<dl compact="compact"> +<dt><span>‘<samp>aac_seq_header_detect</samp>’</span></dt> +<dd><p>Place AAC sequence header based on audio stream data. +</p> +</dd> +<dt><span>‘<samp>no_sequence_end</samp>’</span></dt> +<dd><p>Disable sequence end tag. +</p> +</dd> +<dt><span>‘<samp>no_metadata</samp>’</span></dt> +<dd><p>Disable metadata tag. +</p> +</dd> +<dt><span>‘<samp>no_duration_filesize</samp>’</span></dt> +<dd><p>Disable duration and filesize in metadata when they are equal to zero +at the end of stream. (Be used to non-seekable living stream). +</p> +</dd> +<dt><span>‘<samp>add_keyframe_index</samp>’</span></dt> +<dd><p>Used to facilitate seeking; particularly for HTTP pseudo streaming. +</p></dd> +</dl> +</dd> +</dl> + +<span id="framecrc"></span><a name="framecrc-1"></a> +<h3 class="section">4.12 framecrc<span class="pull-right"><a class="anchor hidden-xs" href="#framecrc-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-framecrc-1" aria-hidden="true">TOC</a></span></h3> + +<p>Per-packet CRC (Cyclic Redundancy Check) testing format. +</p> +<p>This muxer computes and prints the Adler-32 CRC for each audio +and video packet. By default audio frames are converted to signed +16-bit raw audio and video frames to raw video before computing the +CRC. +</p> +<p>The output of the muxer consists of a line for each audio and video +packet of the form: +</p><div class="example"> +<pre class="example"><var>stream_index</var>, <var>packet_dts</var>, <var>packet_pts</var>, <var>packet_duration</var>, <var>packet_size</var>, 0x<var>CRC</var> +</pre></div> + +<p><var>CRC</var> is a hexadecimal number 0-padded to 8 digits containing the +CRC of the packet. +</p> +<a name="Examples-4"></a> +<h4 class="subsection">4.12.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-4" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-4" aria-hidden="true">TOC</a></span></h4> + +<p>For example to compute the CRC of the audio and video frames in +<samp>INPUT</samp>, converted to raw audio and video packets, and store it +in the file <samp>out.crc</samp>: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f framecrc out.crc +</pre></div> + +<p>To print the information to stdout, use the command: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f framecrc - +</pre></div> + +<p>With <code>ffmpeg</code>, you can select the output format to which the +audio and video frames are encoded before computing the CRC for each +packet by specifying the audio and video codec. For example, to +compute the CRC of each decoded input audio frame converted to PCM +unsigned 8-bit and of each decoded input video frame converted to +MPEG-2 video, use the command: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc - +</pre></div> + +<p>See also the <a href="#crc">crc</a> muxer. +</p> +<span id="framehash"></span><a name="framehash-1"></a> +<h3 class="section">4.13 framehash<span class="pull-right"><a class="anchor hidden-xs" href="#framehash-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-framehash-1" aria-hidden="true">TOC</a></span></h3> + +<p>Per-packet hash testing format. +</p> +<p>This muxer computes and prints a cryptographic hash for each audio +and video packet. This can be used for packet-by-packet equality +checks without having to individually do a binary comparison on each. +</p> +<p>By default audio frames are converted to signed 16-bit raw audio and +video frames to raw video before computing the hash, but the output +of explicit conversions to other codecs can also be used. It uses the +SHA-256 cryptographic hash function by default, but supports several +other algorithms. +</p> +<p>The output of the muxer consists of a line for each audio and video +packet of the form: +</p><div class="example"> +<pre class="example"><var>stream_index</var>, <var>packet_dts</var>, <var>packet_pts</var>, <var>packet_duration</var>, <var>packet_size</var>, <var>hash</var> +</pre></div> + +<p><var>hash</var> is a hexadecimal number representing the computed hash +for the packet. +</p> +<dl compact="compact"> +<dt><span><samp>hash <var>algorithm</var></samp></span></dt> +<dd><p>Use the cryptographic hash function specified by the string <var>algorithm</var>. +Supported values include <code>MD5</code>, <code>murmur3</code>, <code>RIPEMD128</code>, +<code>RIPEMD160</code>, <code>RIPEMD256</code>, <code>RIPEMD320</code>, <code>SHA160</code>, +<code>SHA224</code>, <code>SHA256</code> (default), <code>SHA512/224</code>, <code>SHA512/256</code>, +<code>SHA384</code>, <code>SHA512</code>, <code>CRC32</code> and <code>adler32</code>. +</p> +</dd> +</dl> + +<a name="Examples-5"></a> +<h4 class="subsection">4.13.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-5" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-5" aria-hidden="true">TOC</a></span></h4> + +<p>To compute the SHA-256 hash of the audio and video frames in <samp>INPUT</samp>, +converted to raw audio and video packets, and store it in the file +<samp>out.sha256</samp>: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f framehash out.sha256 +</pre></div> + +<p>To print the information to stdout, using the MD5 hash function, use +the command: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f framehash -hash md5 - +</pre></div> + +<p>See also the <a href="#hash">hash</a> muxer. +</p> +<span id="framemd5"></span><a name="framemd5-1"></a> +<h3 class="section">4.14 framemd5<span class="pull-right"><a class="anchor hidden-xs" href="#framemd5-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-framemd5-1" aria-hidden="true">TOC</a></span></h3> + +<p>Per-packet MD5 testing format. +</p> +<p>This is a variant of the <a href="#framehash">framehash</a> muxer. Unlike that muxer, +it defaults to using the MD5 hash function. +</p> +<a name="Examples-6"></a> +<h4 class="subsection">4.14.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-6" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-6" aria-hidden="true">TOC</a></span></h4> + +<p>To compute the MD5 hash of the audio and video frames in <samp>INPUT</samp>, +converted to raw audio and video packets, and store it in the file +<samp>out.md5</samp>: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f framemd5 out.md5 +</pre></div> + +<p>To print the information to stdout, use the command: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f framemd5 - +</pre></div> + +<p>See also the <a href="#framehash">framehash</a> and <a href="#md5">md5</a> muxers. +</p> +<span id="gif"></span><a name="gif-2"></a> +<h3 class="section">4.15 gif<span class="pull-right"><a class="anchor hidden-xs" href="#gif-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-gif-2" aria-hidden="true">TOC</a></span></h3> + +<p>Animated GIF muxer. +</p> +<p>It accepts the following options: +</p> +<dl compact="compact"> +<dt><span><samp>loop</samp></span></dt> +<dd><p>Set the number of times to loop the output. Use <code>-1</code> for no loop, <code>0</code> +for looping indefinitely (default). +</p> +</dd> +<dt><span><samp>final_delay</samp></span></dt> +<dd><p>Force the delay (expressed in centiseconds) after the last frame. Each frame +ends with a delay until the next frame. The default is <code>-1</code>, which is a +special value to tell the muxer to re-use the previous delay. In case of a +loop, you might want to customize this value to mark a pause for instance. +</p></dd> +</dl> + +<p>For example, to encode a gif looping 10 times, with a 5 seconds delay between +the loops: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif +</pre></div> + +<p>Note 1: if you wish to extract the frames into separate GIF files, you need to +force the <a href="#image2">image2</a> muxer: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif" +</pre></div> + +<p>Note 2: the GIF format has a very large time base: the delay between two frames +can therefore not be smaller than one centi second. +</p> +<span id="hash"></span><a name="hash-1"></a> +<h3 class="section">4.16 hash<span class="pull-right"><a class="anchor hidden-xs" href="#hash-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-hash-1" aria-hidden="true">TOC</a></span></h3> + +<p>Hash testing format. +</p> +<p>This muxer computes and prints a cryptographic hash of all the input +audio and video frames. This can be used for equality checks without +having to do a complete binary comparison. +</p> +<p>By default audio frames are converted to signed 16-bit raw audio and +video frames to raw video before computing the hash, but the output +of explicit conversions to other codecs can also be used. Timestamps +are ignored. It uses the SHA-256 cryptographic hash function by default, +but supports several other algorithms. +</p> +<p>The output of the muxer consists of a single line of the form: +<var>algo</var>=<var>hash</var>, where <var>algo</var> is a short string representing +the hash function used, and <var>hash</var> is a hexadecimal number +representing the computed hash. +</p> +<dl compact="compact"> +<dt><span><samp>hash <var>algorithm</var></samp></span></dt> +<dd><p>Use the cryptographic hash function specified by the string <var>algorithm</var>. +Supported values include <code>MD5</code>, <code>murmur3</code>, <code>RIPEMD128</code>, +<code>RIPEMD160</code>, <code>RIPEMD256</code>, <code>RIPEMD320</code>, <code>SHA160</code>, +<code>SHA224</code>, <code>SHA256</code> (default), <code>SHA512/224</code>, <code>SHA512/256</code>, +<code>SHA384</code>, <code>SHA512</code>, <code>CRC32</code> and <code>adler32</code>. +</p> +</dd> +</dl> + +<a name="Examples-7"></a> +<h4 class="subsection">4.16.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-7" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-7" aria-hidden="true">TOC</a></span></h4> + +<p>To compute the SHA-256 hash of the input converted to raw audio and +video, and store it in the file <samp>out.sha256</samp>: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f hash out.sha256 +</pre></div> + +<p>To print an MD5 hash to stdout use the command: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f hash -hash md5 - +</pre></div> + +<p>See also the <a href="#framehash">framehash</a> muxer. +</p> +<span id="hls"></span><a name="hls-2"></a> +<h3 class="section">4.17 hls<span class="pull-right"><a class="anchor hidden-xs" href="#hls-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-hls-2" aria-hidden="true">TOC</a></span></h3> + +<p>Apple HTTP Live Streaming muxer that segments MPEG-TS according to +the HTTP Live Streaming (HLS) specification. +</p> +<p>It creates a playlist file, and one or more segment files. The output filename +specifies the playlist filename. +</p> +<p>By default, the muxer creates a file for each segment produced. These files +have the same name as the playlist, followed by a sequential number and a +.ts extension. +</p> +<p>Make sure to require a closed GOP when encoding and to set the GOP +size to fit your segment time constraint. +</p> +<p>For example, to convert an input file with <code>ffmpeg</code>: +</p><div class="example"> +<pre class="example">ffmpeg -i in.mkv -c:v h264 -flags +cgop -g 30 -hls_time 1 out.m3u8 +</pre></div> +<p>This example will produce the playlist, <samp>out.m3u8</samp>, and segment files: +<samp>out0.ts</samp>, <samp>out1.ts</samp>, <samp>out2.ts</samp>, etc. +</p> +<p>See also the <a href="#segment">segment</a> muxer, which provides a more generic and +flexible implementation of a segmenter, and can be used to perform HLS +segmentation. +</p> +<a name="Options-9"></a> +<h4 class="subsection">4.17.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-9" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-9" aria-hidden="true">TOC</a></span></h4> + +<p>This muxer supports the following options: +</p> +<dl compact="compact"> +<dt><span><samp>hls_init_time <var>duration</var></samp></span></dt> +<dd><p>Set the initial target segment length. Default value is <var>0</var>. +</p> +<p><var>duration</var> must be a time duration specification, +see <a data-manual="ffmpeg-utils" href="ffmpeg-utils.html#time-duration-syntax">(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual</a>. +</p> +<p>Segment will be cut on the next key frame after this time has passed on the first m3u8 list. +After the initial playlist is filled <code>ffmpeg</code> will cut segments +at duration equal to <code>hls_time</code> +</p> +</dd> +<dt><span><samp>hls_time <var>duration</var></samp></span></dt> +<dd><p>Set the target segment length. Default value is 2. +</p> +<p><var>duration</var> must be a time duration specification, +see <a data-manual="ffmpeg-utils" href="ffmpeg-utils.html#time-duration-syntax">(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual</a>. +Segment will be cut on the next key frame after this time has passed. +</p> +</dd> +<dt><span><samp>hls_list_size <var>size</var></samp></span></dt> +<dd><p>Set the maximum number of playlist entries. If set to 0 the list file +will contain all the segments. Default value is 5. +</p> +</dd> +<dt><span><samp>hls_delete_threshold <var>size</var></samp></span></dt> +<dd><p>Set the number of unreferenced segments to keep on disk before <code>hls_flags delete_segments</code> +deletes them. Increase this to allow continue clients to download segments which +were recently referenced in the playlist. Default value is 1, meaning segments older than +<code>hls_list_size+1</code> will be deleted. +</p> +</dd> +<dt><span><samp>hls_ts_options <var>options_list</var></samp></span></dt> +<dd><p>Set output format options using a :-separated list of key=value +parameters. Values containing <code>:</code> special characters must be +escaped. +<code>hls_ts_options</code> is deprecated, use hls_segment_options instead of it.. +</p> +</dd> +<dt><span><samp>hls_start_number_source</samp></span></dt> +<dd><p>Start the playlist sequence number (<code>#EXT-X-MEDIA-SEQUENCE</code>) according to the specified source. +Unless <code>hls_flags single_file</code> is set, it also specifies source of starting sequence numbers of +segment and subtitle filenames. In any case, if <code>hls_flags append_list</code> +is set and read playlist sequence number is greater than the specified start sequence number, +then that value will be used as start value. +</p> +<p>It accepts the following values: +</p> +<dl compact="compact"> +<dt><span><samp>generic (default)</samp></span></dt> +<dd><p>Set the starting sequence numbers according to <var>start_number</var> option value. +</p> +</dd> +<dt><span><samp>epoch</samp></span></dt> +<dd><p>The start number will be the seconds since epoch (1970-01-01 00:00:00) +</p> +</dd> +<dt><span><samp>epoch_us</samp></span></dt> +<dd><p>The start number will be the microseconds since epoch (1970-01-01 00:00:00) +</p> +</dd> +<dt><span><samp>datetime</samp></span></dt> +<dd><p>The start number will be based on the current date/time as YYYYmmddHHMMSS. e.g. 20161231235759. +</p> +</dd> +</dl> + +</dd> +<dt><span><samp>start_number <var>number</var></samp></span></dt> +<dd><p>Start the playlist sequence number (<code>#EXT-X-MEDIA-SEQUENCE</code>) from the specified <var>number</var> +when <var>hls_start_number_source</var> value is <var>generic</var>. (This is the default case.) +Unless <code>hls_flags single_file</code> is set, it also specifies starting sequence numbers of segment and subtitle filenames. +Default value is 0. +</p> +</dd> +<dt><span><samp>hls_allow_cache <var>allowcache</var></samp></span></dt> +<dd><p>Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments. +</p> +</dd> +<dt><span><samp>hls_base_url <var>baseurl</var></samp></span></dt> +<dd><p>Append <var>baseurl</var> to every entry in the playlist. +Useful to generate playlists with absolute paths. +</p> +<p>Note that the playlist sequence number must be unique for each segment +and it is not to be confused with the segment filename sequence number +which can be cyclic, for example if the <samp>wrap</samp> option is +specified. +</p> +</dd> +<dt><span><samp>hls_segment_filename <var>filename</var></samp></span></dt> +<dd><p>Set the segment filename. Unless <code>hls_flags single_file</code> is set, +<var>filename</var> is used as a string format with the segment number: +</p><div class="example"> +<pre class="example">ffmpeg -i in.nut -hls_segment_filename 'file%03d.ts' out.m3u8 +</pre></div> +<p>This example will produce the playlist, <samp>out.m3u8</samp>, and segment files: +<samp>file000.ts</samp>, <samp>file001.ts</samp>, <samp>file002.ts</samp>, etc. +</p> +<p><var>filename</var> may contain full path or relative path specification, +but only the file name part without any path info will be contained in the m3u8 segment list. +Should a relative path be specified, the path of the created segment +files will be relative to the current working directory. +When strftime_mkdir is set, the whole expanded value of <var>filename</var> will be written into the m3u8 segment list. +</p> +<p>When <code>var_stream_map</code> is set with two or more variant streams, the +<var>filename</var> pattern must contain the string "%v", this string specifies +the position of variant stream index in the generated segment file names. +</p><div class="example"> +<pre class="example">ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \ + -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \ + -hls_segment_filename 'file_%v_%03d.ts' out_%v.m3u8 +</pre></div> +<p>This example will produce the playlists segment file sets: +<samp>file_0_000.ts</samp>, <samp>file_0_001.ts</samp>, <samp>file_0_002.ts</samp>, etc. and +<samp>file_1_000.ts</samp>, <samp>file_1_001.ts</samp>, <samp>file_1_002.ts</samp>, etc. +</p> +<p>The string "%v" may be present in the filename or in the last directory name +containing the file, but only in one of them. (Additionally, %v may appear multiple times in the last +sub-directory or filename.) If the string %v is present in the directory name, then +sub-directories are created after expanding the directory name pattern. This +enables creation of segments corresponding to different variant streams in +subdirectories. +</p><div class="example"> +<pre class="example">ffmpeg -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \ + -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \ + -hls_segment_filename 'vs%v/file_%03d.ts' vs%v/out.m3u8 +</pre></div> +<p>This example will produce the playlists segment file sets: +<samp>vs0/file_000.ts</samp>, <samp>vs0/file_001.ts</samp>, <samp>vs0/file_002.ts</samp>, etc. and +<samp>vs1/file_000.ts</samp>, <samp>vs1/file_001.ts</samp>, <samp>vs1/file_002.ts</samp>, etc. +</p> +</dd> +<dt><span><samp>strftime</samp></span></dt> +<dd><p>Use strftime() on <var>filename</var> to expand the segment filename with localtime. +The segment number is also available in this mode, but to use it, you need to specify second_level_segment_index +hls_flag and %%d will be the specifier. +</p><div class="example"> +<pre class="example">ffmpeg -i in.nut -strftime 1 -hls_segment_filename 'file-%Y%m%d-%s.ts' out.m3u8 +</pre></div> +<p>This example will produce the playlist, <samp>out.m3u8</samp>, and segment files: +<samp>file-20160215-1455569023.ts</samp>, <samp>file-20160215-1455569024.ts</samp>, etc. +Note: On some systems/environments, the <code>%s</code> specifier is not available. See + <code>strftime()</code> documentation. +</p><div class="example"> +<pre class="example">ffmpeg -i in.nut -strftime 1 -hls_flags second_level_segment_index -hls_segment_filename 'file-%Y%m%d-%%04d.ts' out.m3u8 +</pre></div> +<p>This example will produce the playlist, <samp>out.m3u8</samp>, and segment files: +<samp>file-20160215-0001.ts</samp>, <samp>file-20160215-0002.ts</samp>, etc. +</p> +</dd> +<dt><span><samp>strftime_mkdir</samp></span></dt> +<dd><p>Used together with -strftime_mkdir, it will create all subdirectories which +is expanded in <var>filename</var>. +</p><div class="example"> +<pre class="example">ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y%m%d/file-%Y%m%d-%s.ts' out.m3u8 +</pre></div> +<p>This example will create a directory 201560215 (if it does not exist), and then +produce the playlist, <samp>out.m3u8</samp>, and segment files: +<samp>20160215/file-20160215-1455569023.ts</samp>, <samp>20160215/file-20160215-1455569024.ts</samp>, etc. +</p> +<div class="example"> +<pre class="example">ffmpeg -i in.nut -strftime 1 -strftime_mkdir 1 -hls_segment_filename '%Y/%m/%d/file-%Y%m%d-%s.ts' out.m3u8 +</pre></div> +<p>This example will create a directory hierarchy 2016/02/15 (if any of them do not exist), and then +produce the playlist, <samp>out.m3u8</samp>, and segment files: +<samp>2016/02/15/file-20160215-1455569023.ts</samp>, <samp>2016/02/15/file-20160215-1455569024.ts</samp>, etc. +</p> +</dd> +<dt><span><samp>hls_segment_options <var>options_list</var></samp></span></dt> +<dd><p>Set output format options using a :-separated list of key=value +parameters. Values containing <code>:</code> special characters must be +escaped. +</p> +</dd> +<dt><span><samp>hls_key_info_file <var>key_info_file</var></samp></span></dt> +<dd><p>Use the information in <var>key_info_file</var> for segment encryption. The first +line of <var>key_info_file</var> specifies the key URI written to the playlist. The +key URL is used to access the encryption key during playback. The second line +specifies the path to the key file used to obtain the key during the encryption +process. The key file is read as a single packed array of 16 octets in binary +format. The optional third line specifies the initialization vector (IV) as a +hexadecimal string to be used instead of the segment sequence number (default) +for encryption. Changes to <var>key_info_file</var> will result in segment +encryption with the new key/IV and an entry in the playlist for the new key +URI/IV if <code>hls_flags periodic_rekey</code> is enabled. +</p> +<p>Key info file format: +</p><div class="example"> +<pre class="example"><var>key URI</var> +<var>key file path</var> +<var>IV</var> (optional) +</pre></div> + +<p>Example key URIs: +</p><div class="example"> +<pre class="example">http://server/file.key +/path/to/file.key +file.key +</pre></div> + +<p>Example key file paths: +</p><div class="example"> +<pre class="example">file.key +/path/to/file.key +</pre></div> + +<p>Example IV: +</p><div class="example"> +<pre class="example">0123456789ABCDEF0123456789ABCDEF +</pre></div> + +<p>Key info file example: +</p><div class="example"> +<pre class="example">http://server/file.key +/path/to/file.key +0123456789ABCDEF0123456789ABCDEF +</pre></div> + +<p>Example shell script: +</p><div class="example"> +<pre class="example">#!/bin/sh +BASE_URL=${1:-'.'} +openssl rand 16 > file.key +echo $BASE_URL/file.key > file.keyinfo +echo file.key >> file.keyinfo +echo $(openssl rand -hex 16) >> file.keyinfo +ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \ + -hls_key_info_file file.keyinfo out.m3u8 +</pre></div> + +</dd> +<dt><span><samp>-hls_enc <var>enc</var></samp></span></dt> +<dd><p>Enable (1) or disable (0) the AES128 encryption. +When enabled every segment generated is encrypted and the encryption key +is saved as <var>playlist name</var>.key. +</p> +</dd> +<dt><span><samp>-hls_enc_key <var>key</var></samp></span></dt> +<dd><p>16-octet key to encrypt the segments, by default it +is randomly generated. +</p> +</dd> +<dt><span><samp>-hls_enc_key_url <var>keyurl</var></samp></span></dt> +<dd><p>If set, <var>keyurl</var> is prepended instead of <var>baseurl</var> to the key filename +in the playlist. +</p> +</dd> +<dt><span><samp>-hls_enc_iv <var>iv</var></samp></span></dt> +<dd><p>16-octet initialization vector for every segment instead +of the autogenerated ones. +</p> +</dd> +<dt><span><samp>hls_segment_type <var>flags</var></samp></span></dt> +<dd><p>Possible values: +</p> +<dl compact="compact"> +<dt><span>‘<samp>mpegts</samp>’</span></dt> +<dd><p>Output segment files in MPEG-2 Transport Stream format. This is +compatible with all HLS versions. +</p> +</dd> +<dt><span>‘<samp>fmp4</samp>’</span></dt> +<dd><p>Output segment files in fragmented MP4 format, similar to MPEG-DASH. +fmp4 files may be used in HLS version 7 and above. +</p> +</dd> +</dl> + +</dd> +<dt><span><samp>hls_fmp4_init_filename <var>filename</var></samp></span></dt> +<dd><p>Set filename to the fragment files header file, default filename is <samp>init.mp4</samp>. +</p> +<p>Use <code>-strftime 1</code> on <var>filename</var> to expand the segment filename with localtime. +</p><div class="example"> +<pre class="example">ffmpeg -i in.nut -hls_segment_type fmp4 -strftime 1 -hls_fmp4_init_filename "%s_init.mp4" out.m3u8 +</pre></div> +<p>This will produce init like this +<samp>1602678741_init.mp4</samp> +</p> +</dd> +<dt><span><samp>hls_fmp4_init_resend</samp></span></dt> +<dd><p>Resend init file after m3u8 file refresh every time, default is <var>0</var>. +</p> +<p>When <code>var_stream_map</code> is set with two or more variant streams, the +<var>filename</var> pattern must contain the string "%v", this string specifies +the position of variant stream index in the generated init file names. +The string "%v" may be present in the filename or in the last directory name +containing the file. If the string is present in the directory name, then +sub-directories are created after expanding the directory name pattern. This +enables creation of init files corresponding to different variant streams in +subdirectories. +</p> +</dd> +<dt><span><samp>hls_flags <var>flags</var></samp></span></dt> +<dd><p>Possible values: +</p> +<dl compact="compact"> +<dt><span>‘<samp>single_file</samp>’</span></dt> +<dd><p>If this flag is set, the muxer will store all segments in a single MPEG-TS +file, and will use byte ranges in the playlist. HLS playlists generated with +this way will have the version number 4. +For example: +</p><div class="example"> +<pre class="example">ffmpeg -i in.nut -hls_flags single_file out.m3u8 +</pre></div> +<p>Will produce the playlist, <samp>out.m3u8</samp>, and a single segment file, +<samp>out.ts</samp>. +</p> +</dd> +<dt><span>‘<samp>delete_segments</samp>’</span></dt> +<dd><p>Segment files removed from the playlist are deleted after a period of time +equal to the duration of the segment plus the duration of the playlist. +</p> +</dd> +<dt><span>‘<samp>append_list</samp>’</span></dt> +<dd><p>Append new segments into the end of old segment list, +and remove the <code>#EXT-X-ENDLIST</code> from the old segment list. +</p> +</dd> +<dt><span>‘<samp>round_durations</samp>’</span></dt> +<dd><p>Round the duration info in the playlist file segment info to integer +values, instead of using floating point. +If there are no other features requiring higher HLS versions be used, +then this will allow ffmpeg to output a HLS version 2 m3u8. +</p> +</dd> +<dt><span>‘<samp>discont_start</samp>’</span></dt> +<dd><p>Add the <code>#EXT-X-DISCONTINUITY</code> tag to the playlist, before the +first segment’s information. +</p> +</dd> +<dt><span>‘<samp>omit_endlist</samp>’</span></dt> +<dd><p>Do not append the <code>EXT-X-ENDLIST</code> tag at the end of the playlist. +</p> +</dd> +<dt><span>‘<samp>periodic_rekey</samp>’</span></dt> +<dd><p>The file specified by <code>hls_key_info_file</code> will be checked periodically and +detect updates to the encryption info. Be sure to replace this file atomically, +including the file containing the AES encryption key. +</p> +</dd> +<dt><span>‘<samp>independent_segments</samp>’</span></dt> +<dd><p>Add the <code>#EXT-X-INDEPENDENT-SEGMENTS</code> to playlists that has video segments +and when all the segments of that playlist are guaranteed to start with a Key frame. +</p> +</dd> +<dt><span>‘<samp>iframes_only</samp>’</span></dt> +<dd><p>Add the <code>#EXT-X-I-FRAMES-ONLY</code> to playlists that has video segments +and can play only I-frames in the <code>#EXT-X-BYTERANGE</code> mode. +</p> +</dd> +<dt><span>‘<samp>split_by_time</samp>’</span></dt> +<dd><p>Allow segments to start on frames other than keyframes. This improves +behavior on some players when the time between keyframes is inconsistent, +but may make things worse on others, and can cause some oddities during +seeking. This flag should be used with the <code>hls_time</code> option. +</p> +</dd> +<dt><span>‘<samp>program_date_time</samp>’</span></dt> +<dd><p>Generate <code>EXT-X-PROGRAM-DATE-TIME</code> tags. +</p> +</dd> +<dt><span>‘<samp>second_level_segment_index</samp>’</span></dt> +<dd><p>Makes it possible to use segment indexes as %%d in hls_segment_filename expression +besides date/time values when strftime is on. +To get fixed width numbers with trailing zeroes, %%0xd format is available where x is the required width. +</p> +</dd> +<dt><span>‘<samp>second_level_segment_size</samp>’</span></dt> +<dd><p>Makes it possible to use segment sizes (counted in bytes) as %%s in hls_segment_filename +expression besides date/time values when strftime is on. +To get fixed width numbers with trailing zeroes, %%0xs format is available where x is the required width. +</p> +</dd> +<dt><span>‘<samp>second_level_segment_duration</samp>’</span></dt> +<dd><p>Makes it possible to use segment duration (calculated in microseconds) as %%t in hls_segment_filename +expression besides date/time values when strftime is on. +To get fixed width numbers with trailing zeroes, %%0xt format is available where x is the required width. +</p> +<div class="example"> +<pre class="example">ffmpeg -i sample.mpeg \ + -f hls -hls_time 3 -hls_list_size 5 \ + -hls_flags second_level_segment_index+second_level_segment_size+second_level_segment_duration \ + -strftime 1 -strftime_mkdir 1 -hls_segment_filename "segment_%Y%m%d%H%M%S_%%04d_%%08s_%%013t.ts" stream.m3u8 +</pre></div> +<p>This will produce segments like this: +<samp>segment_20170102194334_0003_00122200_0000003000000.ts</samp>, <samp>segment_20170102194334_0004_00120072_0000003000000.ts</samp> etc. +</p> +</dd> +<dt><span>‘<samp>temp_file</samp>’</span></dt> +<dd><p>Write segment data to filename.tmp and rename to filename only once the segment is complete. A webserver +serving up segments can be configured to reject requests to *.tmp to prevent access to in-progress segments +before they have been added to the m3u8 playlist. This flag also affects how m3u8 playlist files are created. +If this flag is set, all playlist files will written into temporary file and renamed after they are complete, similarly as segments are handled. +But playlists with <code>file</code> protocol and with type (<code>hls_playlist_type</code>) other than <code>vod</code> +are always written into temporary file regardless of this flag. Master playlist files (<code>master_pl_name</code>), if any, with <code>file</code> protocol, +are always written into temporary file regardless of this flag if <code>master_pl_publish_rate</code> value is other than zero. +</p> +</dd> +</dl> + +</dd> +<dt><span><samp>hls_playlist_type event</samp></span></dt> +<dd><p>Emit <code>#EXT-X-PLAYLIST-TYPE:EVENT</code> in the m3u8 header. Forces +<samp>hls_list_size</samp> to 0; the playlist can only be appended to. +</p> +</dd> +<dt><span><samp>hls_playlist_type vod</samp></span></dt> +<dd><p>Emit <code>#EXT-X-PLAYLIST-TYPE:VOD</code> in the m3u8 header. Forces +<samp>hls_list_size</samp> to 0; the playlist must not change. +</p> +</dd> +<dt><span><samp>method</samp></span></dt> +<dd><p>Use the given HTTP method to create the hls files. +</p><div class="example"> +<pre class="example">ffmpeg -re -i in.ts -f hls -method PUT http://example.com/live/out.m3u8 +</pre></div> +<p>This example will upload all the mpegts segment files to the HTTP +server using the HTTP PUT method, and update the m3u8 files every +<code>refresh</code> times using the same method. +Note that the HTTP server must support the given method for uploading +files. +</p> +</dd> +<dt><span><samp>http_user_agent</samp></span></dt> +<dd><p>Override User-Agent field in HTTP header. Applicable only for HTTP output. +</p> +</dd> +<dt><span><samp>var_stream_map</samp></span></dt> +<dd><p>Map string which specifies how to group the audio, video and subtitle streams +into different variant streams. The variant stream groups are separated +by space. +Expected string format is like this "a:0,v:0 a:1,v:1 ....". Here a:, v:, s: are +the keys to specify audio, video and subtitle streams respectively. +Allowed values are 0 to 9 (limited just based on practical usage). +</p> +<p>When there are two or more variant streams, the output filename pattern must +contain the string "%v", this string specifies the position of variant stream +index in the output media playlist filenames. The string "%v" may be present in +the filename or in the last directory name containing the file. If the string is +present in the directory name, then sub-directories are created after expanding +the directory name pattern. This enables creation of variant streams in +subdirectories. +</p> +<div class="example"> +<pre class="example">ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \ + -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \ + http://example.com/live/out_%v.m3u8 +</pre></div> +<p>This example creates two hls variant streams. The first variant stream will +contain video stream of bitrate 1000k and audio stream of bitrate 64k and the +second variant stream will contain video stream of bitrate 256k and audio +stream of bitrate 32k. Here, two media playlist with file names out_0.m3u8 and +out_1.m3u8 will be created. If you want something meaningful text instead of indexes +in result names, you may specify names for each or some of the variants +as in the following example. +</p> + +<div class="example"> +<pre class="example">ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \ + -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0,name:my_hd v:1,a:1,name:my_sd" \ + http://example.com/live/out_%v.m3u8 +</pre></div> + +<p>This example creates two hls variant streams as in the previous one. +But here, the two media playlist with file names out_my_hd.m3u8 and +out_my_sd.m3u8 will be created. +</p> +<div class="example"> +<pre class="example">ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k \ + -map 0:v -map 0:a -map 0:v -f hls -var_stream_map "v:0 a:0 v:1" \ + http://example.com/live/out_%v.m3u8 +</pre></div> +<p>This example creates three hls variant streams. The first variant stream will +be a video only stream with video bitrate 1000k, the second variant stream will +be an audio only stream with bitrate 64k and the third variant stream will be a +video only stream with bitrate 256k. Here, three media playlist with file names +out_0.m3u8, out_1.m3u8 and out_2.m3u8 will be created. +</p><div class="example"> +<pre class="example">ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \ + -map 0:v -map 0:a -map 0:v -map 0:a -f hls -var_stream_map "v:0,a:0 v:1,a:1" \ + http://example.com/live/vs_%v/out.m3u8 +</pre></div> +<p>This example creates the variant streams in subdirectories. Here, the first +media playlist is created at <samp>http://example.com/live/vs_0/out.m3u8</samp> and +the second one at <samp>http://example.com/live/vs_1/out.m3u8</samp>. +</p><div class="example"> +<pre class="example">ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k -b:v:1 3000k \ + -map 0:a -map 0:a -map 0:v -map 0:v -f hls \ + -var_stream_map "a:0,agroup:aud_low a:1,agroup:aud_high v:0,agroup:aud_low v:1,agroup:aud_high" \ + -master_pl_name master.m3u8 \ + http://example.com/live/out_%v.m3u8 +</pre></div> +<p>This example creates two audio only and two video only variant streams. In +addition to the #EXT-X-STREAM-INF tag for each variant stream in the master +playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams +and they are mapped to the two video only variant streams with audio group names +’aud_low’ and ’aud_high’. +</p> +<p>By default, a single hls variant containing all the encoded streams is created. +</p> +<div class="example"> +<pre class="example">ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \ + -map 0:a -map 0:a -map 0:v -f hls \ + -var_stream_map "a:0,agroup:aud_low,default:yes a:1,agroup:aud_low v:0,agroup:aud_low" \ + -master_pl_name master.m3u8 \ + http://example.com/live/out_%v.m3u8 +</pre></div> +<p>This example creates two audio only and one video only variant streams. In +addition to the #EXT-X-STREAM-INF tag for each variant stream in the master +playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams +and they are mapped to the one video only variant streams with audio group name +’aud_low’, and the audio group have default stat is NO or YES. +</p> +<p>By default, a single hls variant containing all the encoded streams is created. +</p> +<div class="example"> +<pre class="example">ffmpeg -re -i in.ts -b:a:0 32k -b:a:1 64k -b:v:0 1000k \ + -map 0:a -map 0:a -map 0:v -f hls \ + -var_stream_map "a:0,agroup:aud_low,default:yes,language:ENG a:1,agroup:aud_low,language:CHN v:0,agroup:aud_low" \ + -master_pl_name master.m3u8 \ + http://example.com/live/out_%v.m3u8 +</pre></div> +<p>This example creates two audio only and one video only variant streams. In +addition to the #EXT-X-STREAM-INF tag for each variant stream in the master +playlist, #EXT-X-MEDIA tag is also added for the two audio only variant streams +and they are mapped to the one video only variant streams with audio group name +’aud_low’, and the audio group have default stat is NO or YES, and one audio +have and language is named ENG, the other audio language is named CHN. +</p> +<p>By default, a single hls variant containing all the encoded streams is created. +</p> +<div class="example"> +<pre class="example">ffmpeg -y -i input_with_subtitle.mkv \ + -b:v:0 5250k -c:v h264 -pix_fmt yuv420p -profile:v main -level 4.1 \ + -b:a:0 256k \ + -c:s webvtt -c:a mp2 -ar 48000 -ac 2 -map 0:v -map 0:a:0 -map 0:s:0 \ + -f hls -var_stream_map "v:0,a:0,s:0,sgroup:subtitle" \ + -master_pl_name master.m3u8 -t 300 -hls_time 10 -hls_init_time 4 -hls_list_size \ + 10 -master_pl_publish_rate 10 -hls_flags \ + delete_segments+discont_start+split_by_time ./tmp/video.m3u8 +</pre></div> + +<p>This example adds <code>#EXT-X-MEDIA</code> tag with <code>TYPE=SUBTITLES</code> in +the master playlist with webvtt subtitle group name ’subtitle’. Please make sure +the input file has one text subtitle stream at least. +</p> +</dd> +<dt><span><samp>cc_stream_map</samp></span></dt> +<dd><p>Map string which specifies different closed captions groups and their +attributes. The closed captions stream groups are separated by space. +Expected string format is like this +"ccgroup:<group name>,instreamid:<INSTREAM-ID>,language:<language code> ....". +’ccgroup’ and ’instreamid’ are mandatory attributes. ’language’ is an optional +attribute. +The closed captions groups configured using this option are mapped to different +variant streams by providing the same ’ccgroup’ name in the +<code>var_stream_map</code> string. If <code>var_stream_map</code> is not set, then the +first available ccgroup in <code>cc_stream_map</code> is mapped to the output variant +stream. The examples for these two use cases are given below. +</p> +<div class="example"> +<pre class="example">ffmpeg -re -i in.ts -b:v 1000k -b:a 64k -a53cc 1 -f hls \ + -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en" \ + -master_pl_name master.m3u8 \ + http://example.com/live/out.m3u8 +</pre></div> +<p>This example adds <code>#EXT-X-MEDIA</code> tag with <code>TYPE=CLOSED-CAPTIONS</code> in +the master playlist with group name ’cc’, language ’en’ (english) and +INSTREAM-ID ’CC1’. Also, it adds <code>CLOSED-CAPTIONS</code> attribute with group +name ’cc’ for the output variant stream. +</p><div class="example"> +<pre class="example">ffmpeg -re -i in.ts -b:v:0 1000k -b:v:1 256k -b:a:0 64k -b:a:1 32k \ + -a53cc:0 1 -a53cc:1 1\ + -map 0:v -map 0:a -map 0:v -map 0:a -f hls \ + -cc_stream_map "ccgroup:cc,instreamid:CC1,language:en ccgroup:cc,instreamid:CC2,language:sp" \ + -var_stream_map "v:0,a:0,ccgroup:cc v:1,a:1,ccgroup:cc" \ + -master_pl_name master.m3u8 \ + http://example.com/live/out_%v.m3u8 +</pre></div> +<p>This example adds two <code>#EXT-X-MEDIA</code> tags with <code>TYPE=CLOSED-CAPTIONS</code> in +the master playlist for the INSTREAM-IDs ’CC1’ and ’CC2’. Also, it adds +<code>CLOSED-CAPTIONS</code> attribute with group name ’cc’ for the two output variant +streams. +</p> +</dd> +<dt><span><samp>master_pl_name</samp></span></dt> +<dd><p>Create HLS master playlist with the given name. +</p> +<div class="example"> +<pre class="example">ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 http://example.com/live/out.m3u8 +</pre></div> +<p>This example creates HLS master playlist with name master.m3u8 and it is +published at http://example.com/live/ +</p> +</dd> +<dt><span><samp>master_pl_publish_rate</samp></span></dt> +<dd><p>Publish master play list repeatedly every after specified number of segment intervals. +</p> +<div class="example"> +<pre class="example">ffmpeg -re -i in.ts -f hls -master_pl_name master.m3u8 \ +-hls_time 2 -master_pl_publish_rate 30 http://example.com/live/out.m3u8 +</pre></div> + +<p>This example creates HLS master playlist with name master.m3u8 and keep +publishing it repeatedly every after 30 segments i.e. every after 60s. +</p> +</dd> +<dt><span><samp>http_persistent</samp></span></dt> +<dd><p>Use persistent HTTP connections. Applicable only for HTTP output. +</p> +</dd> +<dt><span><samp>timeout</samp></span></dt> +<dd><p>Set timeout for socket I/O operations. Applicable only for HTTP output. +</p> +</dd> +<dt><span><samp>-ignore_io_errors</samp></span></dt> +<dd><p>Ignore IO errors during open, write and delete. Useful for long-duration runs with network output. +</p> +</dd> +<dt><span><samp>headers</samp></span></dt> +<dd><p>Set custom HTTP headers, can override built in default headers. Applicable only for HTTP output. +</p> +</dd> +</dl> + +<span id="ico"></span><a name="ico-1"></a> +<h3 class="section">4.18 ico<span class="pull-right"><a class="anchor hidden-xs" href="#ico-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-ico-1" aria-hidden="true">TOC</a></span></h3> + +<p>ICO file muxer. +</p> +<p>Microsoft’s icon file format (ICO) has some strict limitations that should be noted: +</p> +<ul> +<li> Size cannot exceed 256 pixels in any dimension + +</li><li> Only BMP and PNG images can be stored + +</li><li> If a BMP image is used, it must be one of the following pixel formats: +<div class="example"> +<pre class="example">BMP Bit Depth FFmpeg Pixel Format +1bit pal8 +4bit pal8 +8bit pal8 +16bit rgb555le +24bit bgr24 +32bit bgra +</pre></div> + +</li><li> If a BMP image is used, it must use the BITMAPINFOHEADER DIB header + +</li><li> If a PNG image is used, it must use the rgba pixel format +</li></ul> + +<span id="image2"></span><a name="image2-2"></a> +<h3 class="section">4.19 image2<span class="pull-right"><a class="anchor hidden-xs" href="#image2-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-image2-2" aria-hidden="true">TOC</a></span></h3> + +<p>Image file muxer. +</p> +<p>The image file muxer writes video frames to image files. +</p> +<p>The output filenames are specified by a pattern, which can be used to +produce sequentially numbered series of files. +The pattern may contain the string "%d" or "%0<var>N</var>d", this string +specifies the position of the characters representing a numbering in +the filenames. If the form "%0<var>N</var>d" is used, the string +representing the number in each filename is 0-padded to <var>N</var> +digits. The literal character ’%’ can be specified in the pattern with +the string "%%". +</p> +<p>If the pattern contains "%d" or "%0<var>N</var>d", the first filename of +the file list specified will contain the number 1, all the following +numbers will be sequential. +</p> +<p>The pattern may contain a suffix which is used to automatically +determine the format of the image files to write. +</p> +<p>For example the pattern "img-%03d.bmp" will specify a sequence of +filenames of the form <samp>img-001.bmp</samp>, <samp>img-002.bmp</samp>, ..., +<samp>img-010.bmp</samp>, etc. +The pattern "img%%-%d.jpg" will specify a sequence of filenames of the +form <samp>img%-1.jpg</samp>, <samp>img%-2.jpg</samp>, ..., <samp>img%-10.jpg</samp>, +etc. +</p> +<p>The image muxer supports the .Y.U.V image file format. This format is +special in that that each image frame consists of three files, for +each of the YUV420P components. To read or write this image file format, +specify the name of the ’.Y’ file. The muxer will automatically open the +’.U’ and ’.V’ files as required. +</p> +<a name="Options-10"></a> +<h4 class="subsection">4.19.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-10" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-10" aria-hidden="true">TOC</a></span></h4> + +<dl compact="compact"> +<dt><span><samp>frame_pts</samp></span></dt> +<dd><p>If set to 1, expand the filename with pts from pkt->pts. +Default value is 0. +</p> +</dd> +<dt><span><samp>start_number</samp></span></dt> +<dd><p>Start the sequence from the specified number. Default value is 1. +</p> +</dd> +<dt><span><samp>update</samp></span></dt> +<dd><p>If set to 1, the filename will always be interpreted as just a +filename, not a pattern, and the corresponding file will be continuously +overwritten with new images. Default value is 0. +</p> +</dd> +<dt><span><samp>strftime</samp></span></dt> +<dd><p>If set to 1, expand the filename with date and time information from +<code>strftime()</code>. Default value is 0. +</p> +</dd> +<dt><span><samp>atomic_writing</samp></span></dt> +<dd><p>Write output to a temporary file, which is renamed to target filename once +writing is completed. Default is disabled. +</p> +</dd> +<dt><span><samp>protocol_opts <var>options_list</var></samp></span></dt> +<dd><p>Set protocol options as a :-separated list of key=value parameters. Values +containing the <code>:</code> special character must be escaped. +</p> +</dd> +</dl> + +<a name="Examples-8"></a> +<h4 class="subsection">4.19.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-8" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-8" aria-hidden="true">TOC</a></span></h4> + +<p>The following example shows how to use <code>ffmpeg</code> for creating a +sequence of files <samp>img-001.jpeg</samp>, <samp>img-002.jpeg</samp>, ..., +taking one image every second from the input video: +</p><div class="example"> +<pre class="example">ffmpeg -i in.avi -vsync cfr -r 1 -f image2 'img-%03d.jpeg' +</pre></div> + +<p>Note that with <code>ffmpeg</code>, if the format is not specified with the +<code>-f</code> option and the output filename specifies an image file +format, the image2 muxer is automatically selected, so the previous +command can be written as: +</p><div class="example"> +<pre class="example">ffmpeg -i in.avi -vsync cfr -r 1 'img-%03d.jpeg' +</pre></div> + +<p>Note also that the pattern must not necessarily contain "%d" or +"%0<var>N</var>d", for example to create a single image file +<samp>img.jpeg</samp> from the start of the input video you can employ the command: +</p><div class="example"> +<pre class="example">ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg +</pre></div> + +<p>The <samp>strftime</samp> option allows you to expand the filename with +date and time information. Check the documentation of +the <code>strftime()</code> function for the syntax. +</p> +<p>For example to generate image files from the <code>strftime()</code> +"%Y-%m-%d_%H-%M-%S" pattern, the following <code>ffmpeg</code> command +can be used: +</p><div class="example"> +<pre class="example">ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg" +</pre></div> + +<p>You can set the file name with current frame’s PTS: +</p><div class="example"> +<pre class="example">ffmpeg -f v4l2 -r 1 -i /dev/video0 -copyts -f image2 -frame_pts true %d.jpg" +</pre></div> + +<p>A more complex example is to publish contents of your desktop directly to a +WebDAV server every second: +</p><div class="example"> +<pre class="example">ffmpeg -f x11grab -framerate 1 -i :0.0 -q:v 6 -update 1 -protocol_opts method=PUT http://example.com/desktop.jpg +</pre></div> + +<a name="matroska"></a> +<h3 class="section">4.20 matroska<span class="pull-right"><a class="anchor hidden-xs" href="#matroska" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-matroska" aria-hidden="true">TOC</a></span></h3> + +<p>Matroska container muxer. +</p> +<p>This muxer implements the matroska and webm container specs. +</p> +<a name="Metadata"></a> +<h4 class="subsection">4.20.1 Metadata<span class="pull-right"><a class="anchor hidden-xs" href="#Metadata" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Metadata" aria-hidden="true">TOC</a></span></h4> + +<p>The recognized metadata settings in this muxer are: +</p> +<dl compact="compact"> +<dt><span><samp>title</samp></span></dt> +<dd><p>Set title name provided to a single track. This gets mapped to +the FileDescription element for a stream written as attachment. +</p> +</dd> +<dt><span><samp>language</samp></span></dt> +<dd><p>Specify the language of the track in the Matroska languages form. +</p> +<p>The language can be either the 3 letters bibliographic ISO-639-2 (ISO +639-2/B) form (like "fre" for French), or a language code mixed with a +country code for specialities in languages (like "fre-ca" for Canadian +French). +</p> +</dd> +<dt><span><samp>stereo_mode</samp></span></dt> +<dd><p>Set stereo 3D video layout of two views in a single video track. +</p> +<p>The following values are recognized: +</p><dl compact="compact"> +<dt><span>‘<samp>mono</samp>’</span></dt> +<dd><p>video is not stereo +</p></dd> +<dt><span>‘<samp>left_right</samp>’</span></dt> +<dd><p>Both views are arranged side by side, Left-eye view is on the left +</p></dd> +<dt><span>‘<samp>bottom_top</samp>’</span></dt> +<dd><p>Both views are arranged in top-bottom orientation, Left-eye view is at bottom +</p></dd> +<dt><span>‘<samp>top_bottom</samp>’</span></dt> +<dd><p>Both views are arranged in top-bottom orientation, Left-eye view is on top +</p></dd> +<dt><span>‘<samp>checkerboard_rl</samp>’</span></dt> +<dd><p>Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first +</p></dd> +<dt><span>‘<samp>checkerboard_lr</samp>’</span></dt> +<dd><p>Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first +</p></dd> +<dt><span>‘<samp>row_interleaved_rl</samp>’</span></dt> +<dd><p>Each view is constituted by a row based interleaving, Right-eye view is first row +</p></dd> +<dt><span>‘<samp>row_interleaved_lr</samp>’</span></dt> +<dd><p>Each view is constituted by a row based interleaving, Left-eye view is first row +</p></dd> +<dt><span>‘<samp>col_interleaved_rl</samp>’</span></dt> +<dd><p>Both views are arranged in a column based interleaving manner, Right-eye view is first column +</p></dd> +<dt><span>‘<samp>col_interleaved_lr</samp>’</span></dt> +<dd><p>Both views are arranged in a column based interleaving manner, Left-eye view is first column +</p></dd> +<dt><span>‘<samp>anaglyph_cyan_red</samp>’</span></dt> +<dd><p>All frames are in anaglyph format viewable through red-cyan filters +</p></dd> +<dt><span>‘<samp>right_left</samp>’</span></dt> +<dd><p>Both views are arranged side by side, Right-eye view is on the left +</p></dd> +<dt><span>‘<samp>anaglyph_green_magenta</samp>’</span></dt> +<dd><p>All frames are in anaglyph format viewable through green-magenta filters +</p></dd> +<dt><span>‘<samp>block_lr</samp>’</span></dt> +<dd><p>Both eyes laced in one Block, Left-eye view is first +</p></dd> +<dt><span>‘<samp>block_rl</samp>’</span></dt> +<dd><p>Both eyes laced in one Block, Right-eye view is first +</p></dd> +</dl> +</dd> +</dl> + +<p>For example a 3D WebM clip can be created using the following command line: +</p><div class="example"> +<pre class="example">ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm +</pre></div> + +<a name="Options-11"></a> +<h4 class="subsection">4.20.2 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-11" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-11" aria-hidden="true">TOC</a></span></h4> + +<p>This muxer supports the following options: +</p> +<dl compact="compact"> +<dt><span><samp>reserve_index_space</samp></span></dt> +<dd><p>By default, this muxer writes the index for seeking (called cues in Matroska +terms) at the end of the file, because it cannot know in advance how much space +to leave for the index at the beginning of the file. However for some use cases +– e.g. streaming where seeking is possible but slow – it is useful to put the +index at the beginning of the file. +</p> +<p>If this option is set to a non-zero value, the muxer will reserve a given amount +of space in the file header and then try to write the cues there when the muxing +finishes. If the reserved space does not suffice, no Cues will be written, the +file will be finalized and writing the trailer will return an error. +A safe size for most use cases should be about 50kB per hour of video. +</p> +<p>Note that cues are only written if the output is seekable and this option will +have no effect if it is not. +</p> +</dd> +<dt><span><samp>cues_to_front</samp></span></dt> +<dd><p>If set, the muxer will write the index at the beginning of the file +by shifting the main data if necessary. This can be combined with +reserve_index_space in which case the data is only shifted if +the initially reserved space turns out to be insufficient. +</p> +<p>This option is ignored if the output is unseekable. +</p> +</dd> +<dt><span><samp>default_mode</samp></span></dt> +<dd><p>This option controls how the FlagDefault of the output tracks will be set. +It influences which tracks players should play by default. The default mode +is ‘<samp>passthrough</samp>’. +</p><dl compact="compact"> +<dt><span>‘<samp>infer</samp>’</span></dt> +<dd><p>Every track with disposition default will have the FlagDefault set. +Additionally, for each type of track (audio, video or subtitle), if no track +with disposition default of this type exists, then the first track of this type +will be marked as default (if existing). This ensures that the default flag +is set in a sensible way even if the input originated from containers that +lack the concept of default tracks. +</p></dd> +<dt><span>‘<samp>infer_no_subs</samp>’</span></dt> +<dd><p>This mode is the same as infer except that if no subtitle track with +disposition default exists, no subtitle track will be marked as default. +</p></dd> +<dt><span>‘<samp>passthrough</samp>’</span></dt> +<dd><p>In this mode the FlagDefault is set if and only if the AV_DISPOSITION_DEFAULT +flag is set in the disposition of the corresponding stream. +</p></dd> +</dl> + +</dd> +<dt><span><samp>flipped_raw_rgb</samp></span></dt> +<dd><p>If set to true, store positive height for raw RGB bitmaps, which indicates +bitmap is stored bottom-up. Note that this option does not flip the bitmap +which has to be done manually beforehand, e.g. by using the vflip filter. +Default is <var>false</var> and indicates bitmap is stored top down. +</p> +</dd> +</dl> + +<span id="md5"></span><a name="md5-1"></a> +<h3 class="section">4.21 md5<span class="pull-right"><a class="anchor hidden-xs" href="#md5-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-md5-1" aria-hidden="true">TOC</a></span></h3> + +<p>MD5 testing format. +</p> +<p>This is a variant of the <a href="#hash">hash</a> muxer. Unlike that muxer, it +defaults to using the MD5 hash function. +</p> +<a name="Examples-9"></a> +<h4 class="subsection">4.21.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-9" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-9" aria-hidden="true">TOC</a></span></h4> + +<p>To compute the MD5 hash of the input converted to raw +audio and video, and store it in the file <samp>out.md5</samp>: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f md5 out.md5 +</pre></div> + +<p>You can print the MD5 to stdout with the command: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f md5 - +</pre></div> + +<p>See also the <a href="#hash">hash</a> and <a href="#framemd5">framemd5</a> muxers. +</p> +<a name="mov_002c-mp4_002c-ismv"></a> +<h3 class="section">4.22 mov, mp4, ismv<span class="pull-right"><a class="anchor hidden-xs" href="#mov_002c-mp4_002c-ismv" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mov_002c-mp4_002c-ismv" aria-hidden="true">TOC</a></span></h3> + +<p>MOV/MP4/ISMV (Smooth Streaming) muxer. +</p> +<p>The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4 +file has all the metadata about all packets stored in one location +(written at the end of the file, it can be moved to the start for +better playback by adding <var>faststart</var> to the <var>movflags</var>, or +using the <code>qt-faststart</code> tool). A fragmented +file consists of a number of fragments, where packets and metadata +about these packets are stored together. Writing a fragmented +file has the advantage that the file is decodable even if the +writing is interrupted (while a normal MOV/MP4 is undecodable if +it is not properly finished), and it requires less memory when writing +very long files (since writing normal MOV/MP4 files stores info about +every single packet in memory until the file is closed). The downside +is that it is less compatible with other applications. +</p> +<a name="Options-12"></a> +<h4 class="subsection">4.22.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-12" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-12" aria-hidden="true">TOC</a></span></h4> + +<p>Fragmentation is enabled by setting one of the AVOptions that define +how to cut the file into fragments: +</p> +<dl compact="compact"> +<dt><span><samp>-moov_size <var>bytes</var></samp></span></dt> +<dd><p>Reserves space for the moov atom at the beginning of the file instead of placing the +moov atom at the end. If the space reserved is insufficient, muxing will fail. +</p></dd> +<dt><span><samp>-movflags frag_keyframe</samp></span></dt> +<dd><p>Start a new fragment at each video keyframe. +</p></dd> +<dt><span><samp>-frag_duration <var>duration</var></samp></span></dt> +<dd><p>Create fragments that are <var>duration</var> microseconds long. +</p></dd> +<dt><span><samp>-frag_size <var>size</var></samp></span></dt> +<dd><p>Create fragments that contain up to <var>size</var> bytes of payload data. +</p></dd> +<dt><span><samp>-movflags frag_custom</samp></span></dt> +<dd><p>Allow the caller to manually choose when to cut fragments, by +calling <code>av_write_frame(ctx, NULL)</code> to write a fragment with +the packets written so far. (This is only useful with other +applications integrating libavformat, not from <code>ffmpeg</code>.) +</p></dd> +<dt><span><samp>-min_frag_duration <var>duration</var></samp></span></dt> +<dd><p>Don’t create fragments that are shorter than <var>duration</var> microseconds long. +</p></dd> +</dl> + +<p>If more than one condition is specified, fragments are cut when +one of the specified conditions is fulfilled. The exception to this is +<code>-min_frag_duration</code>, which has to be fulfilled for any of the other +conditions to apply. +</p> +<p>Additionally, the way the output file is written can be adjusted +through a few other options: +</p> +<dl compact="compact"> +<dt><span><samp>-movflags empty_moov</samp></span></dt> +<dd><p>Write an initial moov atom directly at the start of the file, without +describing any samples in it. Generally, an mdat/moov pair is written +at the start of the file, as a normal MOV/MP4 file, containing only +a short portion of the file. With this option set, there is no initial +mdat atom, and the moov atom only describes the tracks but has +a zero duration. +</p> +<p>This option is implicitly set when writing ismv (Smooth Streaming) files. +</p></dd> +<dt><span><samp>-movflags separate_moof</samp></span></dt> +<dd><p>Write a separate moof (movie fragment) atom for each track. Normally, +packets for all tracks are written in a moof atom (which is slightly +more efficient), but with this option set, the muxer writes one moof/mdat +pair for each track, making it easier to separate tracks. +</p> +<p>This option is implicitly set when writing ismv (Smooth Streaming) files. +</p></dd> +<dt><span><samp>-movflags skip_sidx</samp></span></dt> +<dd><p>Skip writing of sidx atom. When bitrate overhead due to sidx atom is high, +this option could be used for cases where sidx atom is not mandatory. +When global_sidx flag is enabled, this option will be ignored. +</p></dd> +<dt><span><samp>-movflags faststart</samp></span></dt> +<dd><p>Run a second pass moving the index (moov atom) to the beginning of the file. +This operation can take a while, and will not work in various situations such +as fragmented output, thus it is not enabled by default. +</p></dd> +<dt><span><samp>-movflags rtphint</samp></span></dt> +<dd><p>Add RTP hinting tracks to the output file. +</p></dd> +<dt><span><samp>-movflags disable_chpl</samp></span></dt> +<dd><p>Disable Nero chapter markers (chpl atom). Normally, both Nero chapters +and a QuickTime chapter track are written to the file. With this option +set, only the QuickTime chapter track will be written. Nero chapters can +cause failures when the file is reprocessed with certain tagging programs, like +mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well. +</p></dd> +<dt><span><samp>-movflags omit_tfhd_offset</samp></span></dt> +<dd><p>Do not write any absolute base_data_offset in tfhd atoms. This avoids +tying fragments to absolute byte positions in the file/streams. +</p></dd> +<dt><span><samp>-movflags default_base_moof</samp></span></dt> +<dd><p>Similarly to the omit_tfhd_offset, this flag avoids writing the +absolute base_data_offset field in tfhd atoms, but does so by using +the new default-base-is-moof flag instead. This flag is new from +14496-12:2012. This may make the fragments easier to parse in certain +circumstances (avoiding basing track fragment location calculations +on the implicit end of the previous track fragment). +</p></dd> +<dt><span><samp>-write_tmcd</samp></span></dt> +<dd><p>Specify <code>on</code> to force writing a timecode track, <code>off</code> to disable it +and <code>auto</code> to write a timecode track only for mov and mp4 output (default). +</p></dd> +<dt><span><samp>-movflags negative_cts_offsets</samp></span></dt> +<dd><p>Enables utilization of version 1 of the CTTS box, in which the CTS offsets can +be negative. This enables the initial sample to have DTS/CTS of zero, and +reduces the need for edit lists for some cases such as video tracks with +B-frames. Additionally, eases conformance with the DASH-IF interoperability +guidelines. +</p> +<p>This option is implicitly set when writing ismv (Smooth Streaming) files. +</p> +</dd> +<dt><span><samp>-write_btrt <var>bool</var></samp></span></dt> +<dd><p>Force or disable writing bitrate box inside stsd box of a track. +The box contains decoding buffer size (in bytes), maximum bitrate and +average bitrate for the track. The box will be skipped if none of these values +can be computed. +Default is <code>-1</code> or <code>auto</code>, which will write the box only in MP4 mode. +</p> +</dd> +<dt><span><samp>-write_prft</samp></span></dt> +<dd><p>Write producer time reference box (PRFT) with a specified time source for the +NTP field in the PRFT box. Set value as ‘<samp>wallclock</samp>’ to specify timesource +as wallclock time and ‘<samp>pts</samp>’ to specify timesource as input packets’ PTS +values. +</p> +<p>Setting value to ‘<samp>pts</samp>’ is applicable only for a live encoding use case, +where PTS values are set as as wallclock time at the source. For example, an +encoding use case with decklink capture source where <samp>video_pts</samp> and +<samp>audio_pts</samp> are set to ‘<samp>abs_wallclock</samp>’. +</p> +</dd> +<dt><span><samp>-empty_hdlr_name <var>bool</var></samp></span></dt> +<dd><p>Enable to skip writing the name inside a <code>hdlr</code> box. +Default is <code>false</code>. +</p> +</dd> +<dt><span><samp>-movie_timescale <var>scale</var></samp></span></dt> +<dd><p>Set the timescale written in the movie header box (<code>mvhd</code>). +Range is 1 to INT_MAX. Default is 1000. +</p> +</dd> +<dt><span><samp>-video_track_timescale <var>scale</var></samp></span></dt> +<dd><p>Set the timescale used for video tracks. Range is 0 to INT_MAX. +If set to <code>0</code>, the timescale is automatically set based on +the native stream time base. Default is 0. +</p></dd> +</dl> + +<a name="Example"></a> +<h4 class="subsection">4.22.2 Example<span class="pull-right"><a class="anchor hidden-xs" href="#Example" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Example" aria-hidden="true">TOC</a></span></h4> + +<p>Smooth Streaming content can be pushed in real time to a publishing +point on IIS with this muxer. Example: +</p><div class="example"> +<pre class="example">ffmpeg -re <var><normal input/transcoding options></var> -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1) +</pre></div> + +<a name="mp3"></a> +<h3 class="section">4.23 mp3<span class="pull-right"><a class="anchor hidden-xs" href="#mp3" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mp3" aria-hidden="true">TOC</a></span></h3> + +<p>The MP3 muxer writes a raw MP3 stream with the following optional features: +</p><ul> +<li> An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and +2.4 are supported, the <code>id3v2_version</code> private option controls which one is +used (3 or 4). Setting <code>id3v2_version</code> to 0 disables the ID3v2 header +completely. + +<p>The muxer supports writing attached pictures (APIC frames) to the ID3v2 header. +The pictures are supplied to the muxer in form of a video stream with a single +packet. There can be any number of those streams, each will correspond to a +single APIC frame. The stream metadata tags <var>title</var> and <var>comment</var> map +to APIC <var>description</var> and <var>picture type</var> respectively. See +<a href="http://id3.org/id3v2.4.0-frames">http://id3.org/id3v2.4.0-frames</a> for allowed picture types. +</p> +<p>Note that the APIC frames must be written at the beginning, so the muxer will +buffer the audio frames until it gets all the pictures. It is therefore advised +to provide the pictures as soon as possible to avoid excessive buffering. +</p> +</li><li> A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by +default, but will be written only if the output is seekable. The +<code>write_xing</code> private option can be used to disable it. The frame contains +various information that may be useful to the decoder, like the audio duration +or encoder delay. + +</li><li> A legacy ID3v1 tag at the end of the file (disabled by default). It may be +enabled with the <code>write_id3v1</code> private option, but as its capabilities are +very limited, its usage is not recommended. +</li></ul> + +<p>Examples: +</p> +<p>Write an mp3 with an ID3v2.3 header and an ID3v1 footer: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3 +</pre></div> + +<p>To attach a picture to an mp3 file select both the audio and the picture stream +with <code>map</code>: +</p><div class="example"> +<pre class="example">ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1 +-metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3 +</pre></div> + +<p>Write a "clean" MP3 without any extra features: +</p><div class="example"> +<pre class="example">ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3 +</pre></div> + +<a name="mpegts-1"></a> +<h3 class="section">4.24 mpegts<span class="pull-right"><a class="anchor hidden-xs" href="#mpegts-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mpegts-1" aria-hidden="true">TOC</a></span></h3> + +<p>MPEG transport stream muxer. +</p> +<p>This muxer implements ISO 13818-1 and part of ETSI EN 300 468. +</p> +<p>The recognized metadata settings in mpegts muxer are <code>service_provider</code> +and <code>service_name</code>. If they are not set the default for +<code>service_provider</code> is ‘<samp>FFmpeg</samp>’ and the default for +<code>service_name</code> is ‘<samp>Service01</samp>’. +</p> +<a name="Options-13"></a> +<h4 class="subsection">4.24.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-13" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-13" aria-hidden="true">TOC</a></span></h4> + +<p>The muxer options are: +</p> +<dl compact="compact"> +<dt><span><samp>mpegts_transport_stream_id <var>integer</var></samp></span></dt> +<dd><p>Set the ‘<samp>transport_stream_id</samp>’. This identifies a transponder in DVB. +Default is <code>0x0001</code>. +</p> +</dd> +<dt><span><samp>mpegts_original_network_id <var>integer</var></samp></span></dt> +<dd><p>Set the ‘<samp>original_network_id</samp>’. This is unique identifier of a +network in DVB. Its main use is in the unique identification of a service +through the path ‘<samp>Original_Network_ID, Transport_Stream_ID</samp>’. Default +is <code>0x0001</code>. +</p> +</dd> +<dt><span><samp>mpegts_service_id <var>integer</var></samp></span></dt> +<dd><p>Set the ‘<samp>service_id</samp>’, also known as program in DVB. Default is +<code>0x0001</code>. +</p> +</dd> +<dt><span><samp>mpegts_service_type <var>integer</var></samp></span></dt> +<dd><p>Set the program ‘<samp>service_type</samp>’. Default is <code>digital_tv</code>. +Accepts the following options: +</p><dl compact="compact"> +<dt><span>‘<samp>hex_value</samp>’</span></dt> +<dd><p>Any hexadecimal value between <code>0x01</code> and <code>0xff</code> as defined in +ETSI 300 468. +</p></dd> +<dt><span>‘<samp>digital_tv</samp>’</span></dt> +<dd><p>Digital TV service. +</p></dd> +<dt><span>‘<samp>digital_radio</samp>’</span></dt> +<dd><p>Digital Radio service. +</p></dd> +<dt><span>‘<samp>teletext</samp>’</span></dt> +<dd><p>Teletext service. +</p></dd> +<dt><span>‘<samp>advanced_codec_digital_radio</samp>’</span></dt> +<dd><p>Advanced Codec Digital Radio service. +</p></dd> +<dt><span>‘<samp>mpeg2_digital_hdtv</samp>’</span></dt> +<dd><p>MPEG2 Digital HDTV service. +</p></dd> +<dt><span>‘<samp>advanced_codec_digital_sdtv</samp>’</span></dt> +<dd><p>Advanced Codec Digital SDTV service. +</p></dd> +<dt><span>‘<samp>advanced_codec_digital_hdtv</samp>’</span></dt> +<dd><p>Advanced Codec Digital HDTV service. +</p></dd> +</dl> + +</dd> +<dt><span><samp>mpegts_pmt_start_pid <var>integer</var></samp></span></dt> +<dd><p>Set the first PID for PMTs. Default is <code>0x1000</code>, minimum is <code>0x0020</code>, +maximum is <code>0x1ffa</code>. This option has no effect in m2ts mode where the PMT +PID is fixed <code>0x0100</code>. +</p> +</dd> +<dt><span><samp>mpegts_start_pid <var>integer</var></samp></span></dt> +<dd><p>Set the first PID for elementary streams. Default is <code>0x0100</code>, minimum is +<code>0x0020</code>, maximum is <code>0x1ffa</code>. This option has no effect in m2ts mode +where the elementary stream PIDs are fixed. +</p> +</dd> +<dt><span><samp>mpegts_m2ts_mode <var>boolean</var></samp></span></dt> +<dd><p>Enable m2ts mode if set to <code>1</code>. Default value is <code>-1</code> which +disables m2ts mode. +</p> +</dd> +<dt><span><samp>muxrate <var>integer</var></samp></span></dt> +<dd><p>Set a constant muxrate. Default is VBR. +</p> +</dd> +<dt><span><samp>pes_payload_size <var>integer</var></samp></span></dt> +<dd><p>Set minimum PES packet payload in bytes. Default is <code>2930</code>. +</p> +</dd> +<dt><span><samp>mpegts_flags <var>flags</var></samp></span></dt> +<dd><p>Set mpegts flags. Accepts the following options: +</p><dl compact="compact"> +<dt><span>‘<samp>resend_headers</samp>’</span></dt> +<dd><p>Reemit PAT/PMT before writing the next packet. +</p></dd> +<dt><span>‘<samp>latm</samp>’</span></dt> +<dd><p>Use LATM packetization for AAC. +</p></dd> +<dt><span>‘<samp>pat_pmt_at_frames</samp>’</span></dt> +<dd><p>Reemit PAT and PMT at each video frame. +</p></dd> +<dt><span>‘<samp>system_b</samp>’</span></dt> +<dd><p>Conform to System B (DVB) instead of System A (ATSC). +</p></dd> +<dt><span>‘<samp>initial_discontinuity</samp>’</span></dt> +<dd><p>Mark the initial packet of each stream as discontinuity. +</p></dd> +<dt><span>‘<samp>nit</samp>’</span></dt> +<dd><p>Emit NIT table. +</p></dd> +<dt><span>‘<samp>omit_rai</samp>’</span></dt> +<dd><p>Disable writing of random access indicator. +</p></dd> +</dl> + +</dd> +<dt><span><samp>mpegts_copyts <var>boolean</var></samp></span></dt> +<dd><p>Preserve original timestamps, if value is set to <code>1</code>. Default value +is <code>-1</code>, which results in shifting timestamps so that they start from 0. +</p> +</dd> +<dt><span><samp>omit_video_pes_length <var>boolean</var></samp></span></dt> +<dd><p>Omit the PES packet length for video packets. Default is <code>1</code> (true). +</p> +</dd> +<dt><span><samp>pcr_period <var>integer</var></samp></span></dt> +<dd><p>Override the default PCR retransmission time in milliseconds. Default is +<code>-1</code> which means that the PCR interval will be determined automatically: +20 ms is used for CBR streams, the highest multiple of the frame duration which +is less than 100 ms is used for VBR streams. +</p> +</dd> +<dt><span><samp>pat_period <var>duration</var></samp></span></dt> +<dd><p>Maximum time in seconds between PAT/PMT tables. Default is <code>0.1</code>. +</p> +</dd> +<dt><span><samp>sdt_period <var>duration</var></samp></span></dt> +<dd><p>Maximum time in seconds between SDT tables. Default is <code>0.5</code>. +</p> +</dd> +<dt><span><samp>nit_period <var>duration</var></samp></span></dt> +<dd><p>Maximum time in seconds between NIT tables. Default is <code>0.5</code>. +</p> +</dd> +<dt><span><samp>tables_version <var>integer</var></samp></span></dt> +<dd><p>Set PAT, PMT, SDT and NIT version (default <code>0</code>, valid values are from 0 to 31, inclusively). +This option allows updating stream structure so that standard consumer may +detect the change. To do so, reopen output <code>AVFormatContext</code> (in case of API +usage) or restart <code>ffmpeg</code> instance, cyclically changing +<samp>tables_version</samp> value: +</p> +<div class="example"> +<pre class="example">ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111 +ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111 +... +ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111 +ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111 +ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111 +... +</pre></div> +</dd> +</dl> + +<a name="Example-1"></a> +<h4 class="subsection">4.24.2 Example<span class="pull-right"><a class="anchor hidden-xs" href="#Example-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Example-1" aria-hidden="true">TOC</a></span></h4> + +<div class="example"> +<pre class="example">ffmpeg -i file.mpg -c copy \ + -mpegts_original_network_id 0x1122 \ + -mpegts_transport_stream_id 0x3344 \ + -mpegts_service_id 0x5566 \ + -mpegts_pmt_start_pid 0x1500 \ + -mpegts_start_pid 0x150 \ + -metadata service_provider="Some provider" \ + -metadata service_name="Some Channel" \ + out.ts +</pre></div> + +<a name="mxf_002c-mxf_005fd10_002c-mxf_005fopatom"></a> +<h3 class="section">4.25 mxf, mxf_d10, mxf_opatom<span class="pull-right"><a class="anchor hidden-xs" href="#mxf_002c-mxf_005fd10_002c-mxf_005fopatom" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mxf_002c-mxf_005fd10_002c-mxf_005fopatom" aria-hidden="true">TOC</a></span></h3> + +<p>MXF muxer. +</p> +<a name="Options-14"></a> +<h4 class="subsection">4.25.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-14" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-14" aria-hidden="true">TOC</a></span></h4> + +<p>The muxer options are: +</p> +<dl compact="compact"> +<dt><span><samp>store_user_comments <var>bool</var></samp></span></dt> +<dd><p>Set if user comments should be stored if available or never. +IRT D-10 does not allow user comments. The default is thus to write them for +mxf and mxf_opatom but not for mxf_d10 +</p></dd> +</dl> + +<a name="null"></a> +<h3 class="section">4.26 null<span class="pull-right"><a class="anchor hidden-xs" href="#null" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-null" aria-hidden="true">TOC</a></span></h3> + +<p>Null muxer. +</p> +<p>This muxer does not generate any output file, it is mainly useful for +testing or benchmarking purposes. +</p> +<p>For example to benchmark decoding with <code>ffmpeg</code> you can use the +command: +</p><div class="example"> +<pre class="example">ffmpeg -benchmark -i INPUT -f null out.null +</pre></div> + +<p>Note that the above command does not read or write the <samp>out.null</samp> +file, but specifying the output file is required by the <code>ffmpeg</code> +syntax. +</p> +<p>Alternatively you can write the command as: +</p><div class="example"> +<pre class="example">ffmpeg -benchmark -i INPUT -f null - +</pre></div> + +<a name="nut"></a> +<h3 class="section">4.27 nut<span class="pull-right"><a class="anchor hidden-xs" href="#nut" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-nut" aria-hidden="true">TOC</a></span></h3> + +<dl compact="compact"> +<dt><span><samp>-syncpoints <var>flags</var></samp></span></dt> +<dd><p>Change the syncpoint usage in nut: +</p><dl compact="compact"> +<dt><span><samp><var>default</var> use the normal low-overhead seeking aids.</samp></span></dt> +<dt><span><samp><var>none</var> do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;</samp></span></dt> +<dd><p>Use of this option is not recommended, as the resulting files are very damage + sensitive and seeking is not possible. Also in general the overhead from + syncpoints is negligible. Note, -<code>write_index</code> 0 can be used to disable + all growing data tables, allowing to mux endless streams with limited memory + and without these disadvantages. +</p></dd> +<dt><span><samp><var>timestamped</var> extend the syncpoint with a wallclock field.</samp></span></dt> +</dl> +<p>The <var>none</var> and <var>timestamped</var> flags are experimental. +</p></dd> +<dt><span><samp>-write_index <var>bool</var></samp></span></dt> +<dd><p>Write index at the end, the default is to write an index. +</p></dd> +</dl> + +<div class="example"> +<pre class="example">ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor +</pre></div> + +<a name="ogg"></a> +<h3 class="section">4.28 ogg<span class="pull-right"><a class="anchor hidden-xs" href="#ogg" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-ogg" aria-hidden="true">TOC</a></span></h3> + +<p>Ogg container muxer. +</p> +<dl compact="compact"> +<dt><span><samp>-page_duration <var>duration</var></samp></span></dt> +<dd><p>Preferred page duration, in microseconds. The muxer will attempt to create +pages that are approximately <var>duration</var> microseconds long. This allows the +user to compromise between seek granularity and container overhead. The default +is 1 second. A value of 0 will fill all segments, making pages as large as +possible. A value of 1 will effectively use 1 packet-per-page in most +situations, giving a small seek granularity at the cost of additional container +overhead. +</p></dd> +<dt><span><samp>-serial_offset <var>value</var></samp></span></dt> +<dd><p>Serial value from which to set the streams serial number. +Setting it to different and sufficiently large values ensures that the produced +ogg files can be safely chained. +</p> +</dd> +</dl> + +<span id="raw-muxers"></span><a name="raw-muxers-1"></a> +<h3 class="section">4.29 raw muxers<span class="pull-right"><a class="anchor hidden-xs" href="#raw-muxers-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-raw-muxers-1" aria-hidden="true">TOC</a></span></h3> + +<p>Raw muxers accept a single stream matching the designated codec. They do not store timestamps or metadata. +The recognized extension is the same as the muxer name unless indicated otherwise. +</p> +<a name="ac3"></a> +<h4 class="subsection">4.29.1 ac3<span class="pull-right"><a class="anchor hidden-xs" href="#ac3" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-ac3" aria-hidden="true">TOC</a></span></h4> + +<p>Dolby Digital, also known as AC-3, audio. +</p> +<a name="adx"></a> +<h4 class="subsection">4.29.2 adx<span class="pull-right"><a class="anchor hidden-xs" href="#adx" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-adx" aria-hidden="true">TOC</a></span></h4> + +<p>CRI Middleware ADX audio. +</p> +<p>This muxer will write out the total sample count near the start of the first packet +when the output is seekable and the count can be stored in 32 bits. +</p> +<a name="aptx"></a> +<h4 class="subsection">4.29.3 aptx<span class="pull-right"><a class="anchor hidden-xs" href="#aptx" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-aptx" aria-hidden="true">TOC</a></span></h4> + +<p>aptX (Audio Processing Technology for Bluetooth) audio. +</p> +<a name="aptx_005fhd"></a> +<h4 class="subsection">4.29.4 aptx_hd<span class="pull-right"><a class="anchor hidden-xs" href="#aptx_005fhd" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-aptx_005fhd" aria-hidden="true">TOC</a></span></h4> + +<p>aptX HD (Audio Processing Technology for Bluetooth) audio. +</p> +<p>Extensions: aptxhd +</p> +<a name="avs2"></a> +<h4 class="subsection">4.29.5 avs2<span class="pull-right"><a class="anchor hidden-xs" href="#avs2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-avs2" aria-hidden="true">TOC</a></span></h4> + +<p>AVS2-P2/IEEE1857.4 video. +</p> +<p>Extensions: avs, avs2 +</p> +<a name="cavsvideo"></a> +<h4 class="subsection">4.29.6 cavsvideo<span class="pull-right"><a class="anchor hidden-xs" href="#cavsvideo" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-cavsvideo" aria-hidden="true">TOC</a></span></h4> + +<p>Chinese AVS (Audio Video Standard) video. +</p> +<p>Extensions: cavs +</p> +<a name="codec2raw"></a> +<h4 class="subsection">4.29.7 codec2raw<span class="pull-right"><a class="anchor hidden-xs" href="#codec2raw" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-codec2raw" aria-hidden="true">TOC</a></span></h4> + +<p>Codec 2 audio. +</p> +<p>No extension is registered so format name has to be supplied e.g. with the ffmpeg CLI tool <code>-f codec2raw</code>. +</p> +<a name="data"></a> +<h4 class="subsection">4.29.8 data<span class="pull-right"><a class="anchor hidden-xs" href="#data" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-data" aria-hidden="true">TOC</a></span></h4> + +<p>Data muxer accepts a single stream with any codec of any type. +The input stream has to be selected using the <code>-map</code> option with the ffmpeg CLI tool. +</p> +<p>No extension is registered so format name has to be supplied e.g. with the ffmpeg CLI tool <code>-f data</code>. +</p> +<a name="dirac"></a> +<h4 class="subsection">4.29.9 dirac<span class="pull-right"><a class="anchor hidden-xs" href="#dirac" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-dirac" aria-hidden="true">TOC</a></span></h4> + +<p>BBC Dirac video. The Dirac Pro codec is a subset and is standardized as SMPTE VC-2. +</p> +<p>Extensions: drc, vc2 +</p> +<a name="dnxhd"></a> +<h4 class="subsection">4.29.10 dnxhd<span class="pull-right"><a class="anchor hidden-xs" href="#dnxhd" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-dnxhd" aria-hidden="true">TOC</a></span></h4> + +<p>Avid DNxHD video. It is standardized as SMPTE VC-3. Accepts DNxHR streams. +</p> +<p>Extensions: dnxhd, dnxhr +</p> +<a name="dts"></a> +<h4 class="subsection">4.29.11 dts<span class="pull-right"><a class="anchor hidden-xs" href="#dts" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-dts" aria-hidden="true">TOC</a></span></h4> + +<p>DTS Coherent Acoustics (DCA) audio. +</p> +<a name="eac3"></a> +<h4 class="subsection">4.29.12 eac3<span class="pull-right"><a class="anchor hidden-xs" href="#eac3" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-eac3" aria-hidden="true">TOC</a></span></h4> + +<p>Dolby Digital Plus, also known as Enhanced AC-3, audio. +</p> +<a name="g722"></a> +<h4 class="subsection">4.29.13 g722<span class="pull-right"><a class="anchor hidden-xs" href="#g722" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-g722" aria-hidden="true">TOC</a></span></h4> + +<p>ITU-T G.722 audio. +</p> +<a name="g723_005f1"></a> +<h4 class="subsection">4.29.14 g723_1<span class="pull-right"><a class="anchor hidden-xs" href="#g723_005f1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-g723_005f1" aria-hidden="true">TOC</a></span></h4> + +<p>ITU-T G.723.1 audio. +</p> +<p>Extensions: tco, rco +</p> +<a name="g726"></a> +<h4 class="subsection">4.29.15 g726<span class="pull-right"><a class="anchor hidden-xs" href="#g726" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-g726" aria-hidden="true">TOC</a></span></h4> + +<p>ITU-T G.726 big-endian ("left-justified") audio. +</p> +<p>No extension is registered so format name has to be supplied e.g. with the ffmpeg CLI tool <code>-f g726</code>. +</p> +<a name="g726le"></a> +<h4 class="subsection">4.29.16 g726le<span class="pull-right"><a class="anchor hidden-xs" href="#g726le" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-g726le" aria-hidden="true">TOC</a></span></h4> + +<p>ITU-T G.726 little-endian ("right-justified") audio. +</p> +<p>No extension is registered so format name has to be supplied e.g. with the ffmpeg CLI tool <code>-f g726le</code>. +</p> +<a name="gsm"></a> +<h4 class="subsection">4.29.17 gsm<span class="pull-right"><a class="anchor hidden-xs" href="#gsm" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-gsm" aria-hidden="true">TOC</a></span></h4> + +<p>Global System for Mobile Communications audio. +</p> +<a name="h261"></a> +<h4 class="subsection">4.29.18 h261<span class="pull-right"><a class="anchor hidden-xs" href="#h261" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-h261" aria-hidden="true">TOC</a></span></h4> + +<p>ITU-T H.261 video. +</p> +<a name="h263"></a> +<h4 class="subsection">4.29.19 h263<span class="pull-right"><a class="anchor hidden-xs" href="#h263" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-h263" aria-hidden="true">TOC</a></span></h4> + +<p>ITU-T H.263 / H.263-1996, H.263+ / H.263-1998 / H.263 version 2 video. +</p> +<a name="h264"></a> +<h4 class="subsection">4.29.20 h264<span class="pull-right"><a class="anchor hidden-xs" href="#h264" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-h264" aria-hidden="true">TOC</a></span></h4> + +<p>ITU-T H.264 / MPEG-4 Part 10 AVC video. Bitstream shall be converted to Annex B syntax if it’s in length-prefixed mode. +</p> +<p>Extensions: h264, 264 +</p> +<a name="hevc"></a> +<h4 class="subsection">4.29.21 hevc<span class="pull-right"><a class="anchor hidden-xs" href="#hevc" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-hevc" aria-hidden="true">TOC</a></span></h4> + +<p>ITU-T H.265 / MPEG-H Part 2 HEVC video. Bitstream shall be converted to Annex B syntax if it’s in length-prefixed mode. +</p> +<p>Extensions: hevc, h265, 265 +</p> +<a name="m4v"></a> +<h4 class="subsection">4.29.22 m4v<span class="pull-right"><a class="anchor hidden-xs" href="#m4v" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-m4v" aria-hidden="true">TOC</a></span></h4> + +<p>MPEG-4 Part 2 video. +</p> +<a name="mjpeg"></a> +<h4 class="subsection">4.29.23 mjpeg<span class="pull-right"><a class="anchor hidden-xs" href="#mjpeg" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mjpeg" aria-hidden="true">TOC</a></span></h4> + +<p>Motion JPEG video. +</p> +<p>Extensions: mjpg, mjpeg +</p> +<a name="mlp"></a> +<h4 class="subsection">4.29.24 mlp<span class="pull-right"><a class="anchor hidden-xs" href="#mlp" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mlp" aria-hidden="true">TOC</a></span></h4> + +<p>Meridian Lossless Packing, also known as Packed PCM, audio. +</p> +<a name="mp2"></a> +<h4 class="subsection">4.29.25 mp2<span class="pull-right"><a class="anchor hidden-xs" href="#mp2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mp2" aria-hidden="true">TOC</a></span></h4> + +<p>MPEG-1 Audio Layer II audio. +</p> +<p>Extensions: mp2, m2a, mpa +</p> +<a name="mpeg1video"></a> +<h4 class="subsection">4.29.26 mpeg1video<span class="pull-right"><a class="anchor hidden-xs" href="#mpeg1video" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mpeg1video" aria-hidden="true">TOC</a></span></h4> + +<p>MPEG-1 Part 2 video. +</p> +<p>Extensions: mpg, mpeg, m1v +</p> +<a name="mpeg2video"></a> +<h4 class="subsection">4.29.27 mpeg2video<span class="pull-right"><a class="anchor hidden-xs" href="#mpeg2video" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-mpeg2video" aria-hidden="true">TOC</a></span></h4> + +<p>ITU-T H.262 / MPEG-2 Part 2 video. +</p> +<p>Extensions: m2v +</p> +<a name="obu"></a> +<h4 class="subsection">4.29.28 obu<span class="pull-right"><a class="anchor hidden-xs" href="#obu" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-obu" aria-hidden="true">TOC</a></span></h4> + +<p>AV1 low overhead Open Bitstream Units muxer. Temporal delimiter OBUs will be inserted in all temporal units of the stream. +</p> +<a name="rawvideo-1"></a> +<h4 class="subsection">4.29.29 rawvideo<span class="pull-right"><a class="anchor hidden-xs" href="#rawvideo-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-rawvideo-1" aria-hidden="true">TOC</a></span></h4> + +<p>Raw uncompressed video. +</p> +<p>Extensions: yuv, rgb +</p> +<a name="sbc"></a> +<h4 class="subsection">4.29.30 sbc<span class="pull-right"><a class="anchor hidden-xs" href="#sbc" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-sbc" aria-hidden="true">TOC</a></span></h4> + +<p>Bluetooth SIG low-complexity subband codec audio. +</p> +<p>Extensions: sbc, msbc +</p> +<a name="truehd"></a> +<h4 class="subsection">4.29.31 truehd<span class="pull-right"><a class="anchor hidden-xs" href="#truehd" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-truehd" aria-hidden="true">TOC</a></span></h4> + +<p>Dolby TrueHD audio. +</p> +<p>Extensions: thd +</p> +<a name="vc1"></a> +<h4 class="subsection">4.29.32 vc1<span class="pull-right"><a class="anchor hidden-xs" href="#vc1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-vc1" aria-hidden="true">TOC</a></span></h4> + +<p>SMPTE 421M / VC-1 video. +</p> +<span id="segment"></span><a name="segment_002c-stream_005fsegment_002c-ssegment"></a> +<h3 class="section">4.30 segment, stream_segment, ssegment<span class="pull-right"><a class="anchor hidden-xs" href="#segment_002c-stream_005fsegment_002c-ssegment" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-segment_002c-stream_005fsegment_002c-ssegment" aria-hidden="true">TOC</a></span></h3> + +<p>Basic stream segmenter. +</p> +<p>This muxer outputs streams to a number of separate files of nearly +fixed duration. Output filename pattern can be set in a fashion +similar to <a href="#image2">image2</a>, or by using a <code>strftime</code> template if +the <samp>strftime</samp> option is enabled. +</p> +<p><code>stream_segment</code> is a variant of the muxer used to write to +streaming output formats, i.e. which do not require global headers, +and is recommended for outputting e.g. to MPEG transport stream segments. +<code>ssegment</code> is a shorter alias for <code>stream_segment</code>. +</p> +<p>Every segment starts with a keyframe of the selected reference stream, +which is set through the <samp>reference_stream</samp> option. +</p> +<p>Note that if you want accurate splitting for a video file, you need to +make the input key frames correspond to the exact splitting times +expected by the segmenter, or the segment muxer will start the new +segment with the key frame found next after the specified start +time. +</p> +<p>The segment muxer works best with a single constant frame rate video. +</p> +<p>Optionally it can generate a list of the created segments, by setting +the option <var>segment_list</var>. The list type is specified by the +<var>segment_list_type</var> option. The entry filenames in the segment +list are set by default to the basename of the corresponding segment +files. +</p> +<p>See also the <a href="#hls">hls</a> muxer, which provides a more specific +implementation for HLS segmentation. +</p> +<a name="Options-15"></a> +<h4 class="subsection">4.30.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-15" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-15" aria-hidden="true">TOC</a></span></h4> + +<p>The segment muxer supports the following options: +</p> +<dl compact="compact"> +<dt><span><samp>increment_tc <var>1|0</var></samp></span></dt> +<dd><p>if set to <code>1</code>, increment timecode between each segment +If this is selected, the input need to have +a timecode in the first video stream. Default value is +<code>0</code>. +</p> +</dd> +<dt><span><samp>reference_stream <var>specifier</var></samp></span></dt> +<dd><p>Set the reference stream, as specified by the string <var>specifier</var>. +If <var>specifier</var> is set to <code>auto</code>, the reference is chosen +automatically. Otherwise it must be a stream specifier (see the “Stream +specifiers” chapter in the ffmpeg manual) which specifies the +reference stream. The default value is <code>auto</code>. +</p> +</dd> +<dt><span><samp>segment_format <var>format</var></samp></span></dt> +<dd><p>Override the inner container format, by default it is guessed by the filename +extension. +</p> +</dd> +<dt><span><samp>segment_format_options <var>options_list</var></samp></span></dt> +<dd><p>Set output format options using a :-separated list of key=value +parameters. Values containing the <code>:</code> special character must be +escaped. +</p> +</dd> +<dt><span><samp>segment_list <var>name</var></samp></span></dt> +<dd><p>Generate also a listfile named <var>name</var>. If not specified no +listfile is generated. +</p> +</dd> +<dt><span><samp>segment_list_flags <var>flags</var></samp></span></dt> +<dd><p>Set flags affecting the segment list generation. +</p> +<p>It currently supports the following flags: +</p><dl compact="compact"> +<dt><span>‘<samp>cache</samp>’</span></dt> +<dd><p>Allow caching (only affects M3U8 list files). +</p> +</dd> +<dt><span>‘<samp>live</samp>’</span></dt> +<dd><p>Allow live-friendly file generation. +</p></dd> +</dl> + +</dd> +<dt><span><samp>segment_list_size <var>size</var></samp></span></dt> +<dd><p>Update the list file so that it contains at most <var>size</var> +segments. If 0 the list file will contain all the segments. Default +value is 0. +</p> +</dd> +<dt><span><samp>segment_list_entry_prefix <var>prefix</var></samp></span></dt> +<dd><p>Prepend <var>prefix</var> to each entry. Useful to generate absolute paths. +By default no prefix is applied. +</p> +</dd> +<dt><span><samp>segment_list_type <var>type</var></samp></span></dt> +<dd><p>Select the listing format. +</p> +<p>The following values are recognized: +</p><dl compact="compact"> +<dt><span>‘<samp>flat</samp>’</span></dt> +<dd><p>Generate a flat list for the created segments, one segment per line. +</p> +</dd> +<dt><span>‘<samp>csv, ext</samp>’</span></dt> +<dd><p>Generate a list for the created segments, one segment per line, +each line matching the format (comma-separated values): +</p><div class="example"> +<pre class="example"><var>segment_filename</var>,<var>segment_start_time</var>,<var>segment_end_time</var> +</pre></div> + +<p><var>segment_filename</var> is the name of the output file generated by the +muxer according to the provided pattern. CSV escaping (according to +RFC4180) is applied if required. +</p> +<p><var>segment_start_time</var> and <var>segment_end_time</var> specify +the segment start and end time expressed in seconds. +</p> +<p>A list file with the suffix <code>".csv"</code> or <code>".ext"</code> will +auto-select this format. +</p> +<p>‘<samp>ext</samp>’ is deprecated in favor or ‘<samp>csv</samp>’. +</p> +</dd> +<dt><span>‘<samp>ffconcat</samp>’</span></dt> +<dd><p>Generate an ffconcat file for the created segments. The resulting file +can be read using the FFmpeg <a href="#concat">concat</a> demuxer. +</p> +<p>A list file with the suffix <code>".ffcat"</code> or <code>".ffconcat"</code> will +auto-select this format. +</p> +</dd> +<dt><span>‘<samp>m3u8</samp>’</span></dt> +<dd><p>Generate an extended M3U8 file, version 3, compliant with +<a href="http://tools.ietf.org/id/draft-pantos-http-live-streaming">http://tools.ietf.org/id/draft-pantos-http-live-streaming</a>. +</p> +<p>A list file with the suffix <code>".m3u8"</code> will auto-select this format. +</p></dd> +</dl> + +<p>If not specified the type is guessed from the list file name suffix. +</p> +</dd> +<dt><span><samp>segment_time <var>time</var></samp></span></dt> +<dd><p>Set segment duration to <var>time</var>, the value must be a duration +specification. Default value is "2". See also the +<samp>segment_times</samp> option. +</p> +<p>Note that splitting may not be accurate, unless you force the +reference stream key-frames at the given time. See the introductory +notice and the examples below. +</p> +</dd> +<dt><span><samp>segment_atclocktime <var>1|0</var></samp></span></dt> +<dd><p>If set to "1" split at regular clock time intervals starting from 00:00 +o’clock. The <var>time</var> value specified in <samp>segment_time</samp> is +used for setting the length of the splitting interval. +</p> +<p>For example with <samp>segment_time</samp> set to "900" this makes it possible +to create files at 12:00 o’clock, 12:15, 12:30, etc. +</p> +<p>Default value is "0". +</p> +</dd> +<dt><span><samp>segment_clocktime_offset <var>duration</var></samp></span></dt> +<dd><p>Delay the segment splitting times with the specified duration when using +<samp>segment_atclocktime</samp>. +</p> +<p>For example with <samp>segment_time</samp> set to "900" and +<samp>segment_clocktime_offset</samp> set to "300" this makes it possible to +create files at 12:05, 12:20, 12:35, etc. +</p> +<p>Default value is "0". +</p> +</dd> +<dt><span><samp>segment_clocktime_wrap_duration <var>duration</var></samp></span></dt> +<dd><p>Force the segmenter to only start a new segment if a packet reaches the muxer +within the specified duration after the segmenting clock time. This way you +can make the segmenter more resilient to backward local time jumps, such as +leap seconds or transition to standard time from daylight savings time. +</p> +<p>Default is the maximum possible duration which means starting a new segment +regardless of the elapsed time since the last clock time. +</p> +</dd> +<dt><span><samp>segment_time_delta <var>delta</var></samp></span></dt> +<dd><p>Specify the accuracy time when selecting the start time for a +segment, expressed as a duration specification. Default value is "0". +</p> +<p>When delta is specified a key-frame will start a new segment if its +PTS satisfies the relation: +</p><div class="example"> +<pre class="example">PTS >= start_time - time_delta +</pre></div> + +<p>This option is useful when splitting video content, which is always +split at GOP boundaries, in case a key frame is found just before the +specified split time. +</p> +<p>In particular may be used in combination with the <samp>ffmpeg</samp> option +<var>force_key_frames</var>. The key frame times specified by +<var>force_key_frames</var> may not be set accurately because of rounding +issues, with the consequence that a key frame time may result set just +before the specified time. For constant frame rate videos a value of +1/(2*<var>frame_rate</var>) should address the worst case mismatch between +the specified time and the time set by <var>force_key_frames</var>. +</p> +</dd> +<dt><span><samp>segment_times <var>times</var></samp></span></dt> +<dd><p>Specify a list of split points. <var>times</var> contains a list of comma +separated duration specifications, in increasing order. See also +the <samp>segment_time</samp> option. +</p> +</dd> +<dt><span><samp>segment_frames <var>frames</var></samp></span></dt> +<dd><p>Specify a list of split video frame numbers. <var>frames</var> contains a +list of comma separated integer numbers, in increasing order. +</p> +<p>This option specifies to start a new segment whenever a reference +stream key frame is found and the sequential number (starting from 0) +of the frame is greater or equal to the next value in the list. +</p> +</dd> +<dt><span><samp>segment_wrap <var>limit</var></samp></span></dt> +<dd><p>Wrap around segment index once it reaches <var>limit</var>. +</p> +</dd> +<dt><span><samp>segment_start_number <var>number</var></samp></span></dt> +<dd><p>Set the sequence number of the first segment. Defaults to <code>0</code>. +</p> +</dd> +<dt><span><samp>strftime <var>1|0</var></samp></span></dt> +<dd><p>Use the <code>strftime</code> function to define the name of the new +segments to write. If this is selected, the output segment name must +contain a <code>strftime</code> function template. Default value is +<code>0</code>. +</p> +</dd> +<dt><span><samp>break_non_keyframes <var>1|0</var></samp></span></dt> +<dd><p>If enabled, allow segments to start on frames other than keyframes. This +improves behavior on some players when the time between keyframes is +inconsistent, but may make things worse on others, and can cause some oddities +during seeking. Defaults to <code>0</code>. +</p> +</dd> +<dt><span><samp>reset_timestamps <var>1|0</var></samp></span></dt> +<dd><p>Reset timestamps at the beginning of each segment, so that each segment +will start with near-zero timestamps. It is meant to ease the playback +of the generated segments. May not work with some combinations of +muxers/codecs. It is set to <code>0</code> by default. +</p> +</dd> +<dt><span><samp>initial_offset <var>offset</var></samp></span></dt> +<dd><p>Specify timestamp offset to apply to the output packet timestamps. The +argument must be a time duration specification, and defaults to 0. +</p> +</dd> +<dt><span><samp>write_empty_segments <var>1|0</var></samp></span></dt> +<dd><p>If enabled, write an empty segment if there are no packets during the period a +segment would usually span. Otherwise, the segment will be filled with the next +packet written. Defaults to <code>0</code>. +</p></dd> +</dl> + +<p>Make sure to require a closed GOP when encoding and to set the GOP +size to fit your segment time constraint. +</p> +<a name="Examples-10"></a> +<h4 class="subsection">4.30.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-10" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-10" aria-hidden="true">TOC</a></span></h4> + +<ul> +<li> Remux the content of file <samp>in.mkv</samp> to a list of segments +<samp>out-000.nut</samp>, <samp>out-001.nut</samp>, etc., and write the list of +generated segments to <samp>out.list</samp>: +<div class="example"> +<pre class="example">ffmpeg -i in.mkv -codec hevc -flags +cgop -g 60 -map 0 -f segment -segment_list out.list out%03d.nut +</pre></div> + +</li><li> Segment input and set output format options for the output segments: +<div class="example"> +<pre class="example">ffmpeg -i in.mkv -f segment -segment_time 10 -segment_format_options movflags=+faststart out%03d.mp4 +</pre></div> + +</li><li> Segment the input file according to the split points specified by the +<var>segment_times</var> option: +<div class="example"> +<pre class="example">ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 out%03d.nut +</pre></div> + +</li><li> Use the <code>ffmpeg</code> <samp>force_key_frames</samp> +option to force key frames in the input at the specified location, together +with the segment option <samp>segment_time_delta</samp> to account for +possible roundings operated when setting key frame times. +<div class="example"> +<pre class="example">ffmpeg -i in.mkv -force_key_frames 1,2,3,5,8,13,21 -codec:v mpeg4 -codec:a pcm_s16le -map 0 \ +-f segment -segment_list out.csv -segment_times 1,2,3,5,8,13,21 -segment_time_delta 0.05 out%03d.nut +</pre></div> +<p>In order to force key frames on the input file, transcoding is +required. +</p> +</li><li> Segment the input file by splitting the input file according to the +frame numbers sequence specified with the <samp>segment_frames</samp> option: +<div class="example"> +<pre class="example">ffmpeg -i in.mkv -codec copy -map 0 -f segment -segment_list out.csv -segment_frames 100,200,300,500,800 out%03d.nut +</pre></div> + +</li><li> Convert the <samp>in.mkv</samp> to TS segments using the <code>libx264</code> +and <code>aac</code> encoders: +<div class="example"> +<pre class="example">ffmpeg -i in.mkv -map 0 -codec:v libx264 -codec:a aac -f ssegment -segment_list out.list out%03d.ts +</pre></div> + +</li><li> Segment the input file, and create an M3U8 live playlist (can be used +as live HLS source): +<div class="example"> +<pre class="example">ffmpeg -re -i in.mkv -codec copy -map 0 -f segment -segment_list playlist.m3u8 \ +-segment_list_flags +live -segment_time 10 out%03d.mkv +</pre></div> +</li></ul> + +<a name="smoothstreaming"></a> +<h3 class="section">4.31 smoothstreaming<span class="pull-right"><a class="anchor hidden-xs" href="#smoothstreaming" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-smoothstreaming" aria-hidden="true">TOC</a></span></h3> + +<p>Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server. +</p> +<dl compact="compact"> +<dt><span><samp>window_size</samp></span></dt> +<dd><p>Specify the number of fragments kept in the manifest. Default 0 (keep all). +</p> +</dd> +<dt><span><samp>extra_window_size</samp></span></dt> +<dd><p>Specify the number of fragments kept outside of the manifest before removing from disk. Default 5. +</p> +</dd> +<dt><span><samp>lookahead_count</samp></span></dt> +<dd><p>Specify the number of lookahead fragments. Default 2. +</p> +</dd> +<dt><span><samp>min_frag_duration</samp></span></dt> +<dd><p>Specify the minimum fragment duration (in microseconds). Default 5000000. +</p> +</dd> +<dt><span><samp>remove_at_exit</samp></span></dt> +<dd><p>Specify whether to remove all fragments when finished. Default 0 (do not remove). +</p> +</dd> +</dl> + +<span id="streamhash"></span><a name="streamhash-1"></a> +<h3 class="section">4.32 streamhash<span class="pull-right"><a class="anchor hidden-xs" href="#streamhash-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-streamhash-1" aria-hidden="true">TOC</a></span></h3> + +<p>Per stream hash testing format. +</p> +<p>This muxer computes and prints a cryptographic hash of all the input frames, +on a per-stream basis. This can be used for equality checks without having +to do a complete binary comparison. +</p> +<p>By default audio frames are converted to signed 16-bit raw audio and +video frames to raw video before computing the hash, but the output +of explicit conversions to other codecs can also be used. Timestamps +are ignored. It uses the SHA-256 cryptographic hash function by default, +but supports several other algorithms. +</p> +<p>The output of the muxer consists of one line per stream of the form: +<var>streamindex</var>,<var>streamtype</var>,<var>algo</var>=<var>hash</var>, where +<var>streamindex</var> is the index of the mapped stream, <var>streamtype</var> is a +single character indicating the type of stream, <var>algo</var> is a short string +representing the hash function used, and <var>hash</var> is a hexadecimal number +representing the computed hash. +</p> +<dl compact="compact"> +<dt><span><samp>hash <var>algorithm</var></samp></span></dt> +<dd><p>Use the cryptographic hash function specified by the string <var>algorithm</var>. +Supported values include <code>MD5</code>, <code>murmur3</code>, <code>RIPEMD128</code>, +<code>RIPEMD160</code>, <code>RIPEMD256</code>, <code>RIPEMD320</code>, <code>SHA160</code>, +<code>SHA224</code>, <code>SHA256</code> (default), <code>SHA512/224</code>, <code>SHA512/256</code>, +<code>SHA384</code>, <code>SHA512</code>, <code>CRC32</code> and <code>adler32</code>. +</p> +</dd> +</dl> + +<a name="Examples-11"></a> +<h4 class="subsection">4.32.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-11" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-11" aria-hidden="true">TOC</a></span></h4> + +<p>To compute the SHA-256 hash of the input converted to raw audio and +video, and store it in the file <samp>out.sha256</samp>: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f streamhash out.sha256 +</pre></div> + +<p>To print an MD5 hash to stdout use the command: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f streamhash -hash md5 - +</pre></div> + +<p>See also the <a href="#hash">hash</a> and <a href="#framehash">framehash</a> muxers. +</p> +<span id="tee"></span><a name="tee-1"></a> +<h3 class="section">4.33 tee<span class="pull-right"><a class="anchor hidden-xs" href="#tee-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-tee-1" aria-hidden="true">TOC</a></span></h3> + +<p>The tee muxer can be used to write the same data to several outputs, such as files or streams. +It can be used, for example, to stream a video over a network and save it to disk at the same time. +</p> +<p>It is different from specifying several outputs to the <code>ffmpeg</code> +command-line tool. With the tee muxer, the audio and video data will be encoded only once. +With conventional multiple outputs, multiple encoding operations in parallel are initiated, +which can be a very expensive process. The tee muxer is not useful when using the libavformat API +directly because it is then possible to feed the same packets to several muxers directly. +</p> +<p>Since the tee muxer does not represent any particular output format, ffmpeg cannot auto-select +output streams. So all streams intended for output must be specified using <code>-map</code>. See +the examples below. +</p> +<p>Some encoders may need different options depending on the output format; +the auto-detection of this can not work with the tee muxer, so they need to be explicitly specified. +The main example is the <samp>global_header</samp> flag. +</p> +<p>The slave outputs are specified in the file name given to the muxer, +separated by ’|’. If any of the slave name contains the ’|’ separator, +leading or trailing spaces or any special character, those must be +escaped (see <a data-manual="ffmpeg-utils" href="ffmpeg-utils.html#quoting_005fand_005fescaping">(ffmpeg-utils)the "Quoting and escaping" +section in the ffmpeg-utils(1) manual</a>). +</p> +<a name="Options-16"></a> +<h4 class="subsection">4.33.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-16" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-16" aria-hidden="true">TOC</a></span></h4> + +<dl compact="compact"> +<dt><span><samp>use_fifo <var>bool</var></samp></span></dt> +<dd><p>If set to 1, slave outputs will be processed in separate threads using the <a href="#fifo">fifo</a> +muxer. This allows to compensate for different speed/latency/reliability of +outputs and setup transparent recovery. By default this feature is turned off. +</p> +</dd> +<dt><span><samp>fifo_options</samp></span></dt> +<dd><p>Options to pass to fifo pseudo-muxer instances. See <a href="#fifo">fifo</a>. +</p> +</dd> +</dl> + +<p>Muxer options can be specified for each slave by prepending them as a list of +<var>key</var>=<var>value</var> pairs separated by ’:’, between square brackets. If +the options values contain a special character or the ’:’ separator, they +must be escaped; note that this is a second level escaping. +</p> +<p>The following special options are also recognized: +</p><dl compact="compact"> +<dt><span><samp>f</samp></span></dt> +<dd><p>Specify the format name. Required if it cannot be guessed from the +output URL. +</p> +</dd> +<dt><span><samp>bsfs[/<var>spec</var>]</samp></span></dt> +<dd><p>Specify a list of bitstream filters to apply to the specified +output. +</p> +<p>It is possible to specify to which streams a given bitstream filter +applies, by appending a stream specifier to the option separated by +<code>/</code>. <var>spec</var> must be a stream specifier (see <a href="#Format-stream-specifiers">Format stream specifiers</a>). +</p> +<p>If the stream specifier is not specified, the bitstream filters will be +applied to all streams in the output. This will cause that output operation +to fail if the output contains streams to which the bitstream filter cannot +be applied e.g. <code>h264_mp4toannexb</code> being applied to an output containing an audio stream. +</p> +<p>Options for a bitstream filter must be specified in the form of <code>opt=value</code>. +</p> +<p>Several bitstream filters can be specified, separated by ",". +</p> +</dd> +<dt><span><samp>use_fifo <var>bool</var></samp></span></dt> +<dd><p>This allows to override tee muxer use_fifo option for individual slave muxer. +</p> +</dd> +<dt><span><samp>fifo_options</samp></span></dt> +<dd><p>This allows to override tee muxer fifo_options for individual slave muxer. +See <a href="#fifo">fifo</a>. +</p> +</dd> +<dt><span><samp>select</samp></span></dt> +<dd><p>Select the streams that should be mapped to the slave output, +specified by a stream specifier. If not specified, this defaults to +all the mapped streams. This will cause that output operation to fail +if the output format does not accept all mapped streams. +</p> +<p>You may use multiple stream specifiers separated by commas (<code>,</code>) e.g.: <code>a:0,v</code> +</p> +</dd> +<dt><span><samp>onfail</samp></span></dt> +<dd><p>Specify behaviour on output failure. This can be set to either <code>abort</code> (which is +default) or <code>ignore</code>. <code>abort</code> will cause whole process to fail in case of failure +on this slave output. <code>ignore</code> will ignore failure on this output, so other outputs +will continue without being affected. +</p></dd> +</dl> + +<a name="Examples-12"></a> +<h4 class="subsection">4.33.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-12" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-12" aria-hidden="true">TOC</a></span></h4> + +<ul> +<li> Encode something and both archive it in a WebM file and stream it +as MPEG-TS over UDP: +<div class="example"> +<pre class="example">ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a + "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/" +</pre></div> + +</li><li> As above, but continue streaming even if output to local file fails +(for example local drive fills up): +<div class="example"> +<pre class="example">ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a + "[onfail=ignore]archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/" +</pre></div> + +</li><li> Use <code>ffmpeg</code> to encode the input, and send the output +to three different destinations. The <code>dump_extra</code> bitstream +filter is used to add extradata information to all the output video +keyframes packets, as requested by the MPEG-TS format. The select +option is applied to <samp>out.aac</samp> in order to make it contain only +audio packets. +<div class="example"> +<pre class="example">ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac + -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac" +</pre></div> + +</li><li> As above, but select only stream <code>a:1</code> for the audio output. Note +that a second level escaping must be performed, as ":" is a special +character used to separate options. +<div class="example"> +<pre class="example">ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac + -f tee "[bsfs/v=dump_extra=freq=keyframe]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac" +</pre></div> +</li></ul> + +<a name="webm_005fchunk"></a> +<h3 class="section">4.34 webm_chunk<span class="pull-right"><a class="anchor hidden-xs" href="#webm_005fchunk" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-webm_005fchunk" aria-hidden="true">TOC</a></span></h3> + +<p>WebM Live Chunk Muxer. +</p> +<p>This muxer writes out WebM headers and chunks as separate files which can be +consumed by clients that support WebM Live streams via DASH. +</p> +<a name="Options-17"></a> +<h4 class="subsection">4.34.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-17" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-17" aria-hidden="true">TOC</a></span></h4> + +<p>This muxer supports the following options: +</p> +<dl compact="compact"> +<dt><span><samp>chunk_start_index</samp></span></dt> +<dd><p>Index of the first chunk (defaults to 0). +</p> +</dd> +<dt><span><samp>header</samp></span></dt> +<dd><p>Filename of the header where the initialization data will be written. +</p> +</dd> +<dt><span><samp>audio_chunk_duration</samp></span></dt> +<dd><p>Duration of each audio chunk in milliseconds (defaults to 5000). +</p></dd> +</dl> + +<a name="Example-2"></a> +<h4 class="subsection">4.34.2 Example<span class="pull-right"><a class="anchor hidden-xs" href="#Example-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Example-2" aria-hidden="true">TOC</a></span></h4> +<div class="example"> +<pre class="example">ffmpeg -f v4l2 -i /dev/video0 \ + -f alsa -i hw:0 \ + -map 0:0 \ + -c:v libvpx-vp9 \ + -s 640x360 -keyint_min 30 -g 30 \ + -f webm_chunk \ + -header webm_live_video_360.hdr \ + -chunk_start_index 1 \ + webm_live_video_360_%d.chk \ + -map 1:0 \ + -c:a libvorbis \ + -b:a 128k \ + -f webm_chunk \ + -header webm_live_audio_128.hdr \ + -chunk_start_index 1 \ + -audio_chunk_duration 1000 \ + webm_live_audio_128_%d.chk +</pre></div> + +<a name="webm_005fdash_005fmanifest"></a> +<h3 class="section">4.35 webm_dash_manifest<span class="pull-right"><a class="anchor hidden-xs" href="#webm_005fdash_005fmanifest" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-webm_005fdash_005fmanifest" aria-hidden="true">TOC</a></span></h3> + +<p>WebM DASH Manifest muxer. +</p> +<p>This muxer implements the WebM DASH Manifest specification to generate the DASH +manifest XML. It also supports manifest generation for DASH live streams. +</p> +<p>For more information see: +</p> +<ul> +<li> WebM DASH Specification: <a href="https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification">https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification</a> +</li><li> ISO DASH Specification: <a href="http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip">http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip</a> +</li></ul> + +<a name="Options-18"></a> +<h4 class="subsection">4.35.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-18" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-18" aria-hidden="true">TOC</a></span></h4> + +<p>This muxer supports the following options: +</p> +<dl compact="compact"> +<dt><span><samp>adaptation_sets</samp></span></dt> +<dd><p>This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the +unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding +audio and video streams. Any number of adaptation sets can be added using this option. +</p> +</dd> +<dt><span><samp>live</samp></span></dt> +<dd><p>Set this to 1 to create a live stream DASH Manifest. Default: 0. +</p> +</dd> +<dt><span><samp>chunk_start_index</samp></span></dt> +<dd><p>Start index of the first chunk. This will go in the ‘<samp>startNumber</samp>’ attribute +of the ‘<samp>SegmentTemplate</samp>’ element in the manifest. Default: 0. +</p> +</dd> +<dt><span><samp>chunk_duration_ms</samp></span></dt> +<dd><p>Duration of each chunk in milliseconds. This will go in the ‘<samp>duration</samp>’ +attribute of the ‘<samp>SegmentTemplate</samp>’ element in the manifest. Default: 1000. +</p> +</dd> +<dt><span><samp>utc_timing_url</samp></span></dt> +<dd><p>URL of the page that will return the UTC timestamp in ISO format. This will go +in the ‘<samp>value</samp>’ attribute of the ‘<samp>UTCTiming</samp>’ element in the manifest. +Default: None. +</p> +</dd> +<dt><span><samp>time_shift_buffer_depth</samp></span></dt> +<dd><p>Smallest time (in seconds) shifting buffer for which any Representation is +guaranteed to be available. This will go in the ‘<samp>timeShiftBufferDepth</samp>’ +attribute of the ‘<samp>MPD</samp>’ element. Default: 60. +</p> +</dd> +<dt><span><samp>minimum_update_period</samp></span></dt> +<dd><p>Minimum update period (in seconds) of the manifest. This will go in the +‘<samp>minimumUpdatePeriod</samp>’ attribute of the ‘<samp>MPD</samp>’ element. Default: 0. +</p> +</dd> +</dl> + +<a name="Example-3"></a> +<h4 class="subsection">4.35.2 Example<span class="pull-right"><a class="anchor hidden-xs" href="#Example-3" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Example-3" aria-hidden="true">TOC</a></span></h4> +<div class="example"> +<pre class="example">ffmpeg -f webm_dash_manifest -i video1.webm \ + -f webm_dash_manifest -i video2.webm \ + -f webm_dash_manifest -i audio1.webm \ + -f webm_dash_manifest -i audio2.webm \ + -map 0 -map 1 -map 2 -map 3 \ + -c copy \ + -f webm_dash_manifest \ + -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \ + manifest.xml +</pre></div> + +<a name="Metadata-1"></a> +<h2 class="chapter">5 Metadata<span class="pull-right"><a class="anchor hidden-xs" href="#Metadata-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Metadata-1" aria-hidden="true">TOC</a></span></h2> + +<p>FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded +INI-like text file and then load it back using the metadata muxer/demuxer. +</p> +<p>The file format is as follows: +</p><ol> +<li> A file consists of a header and a number of metadata tags divided into sections, +each on its own line. + +</li><li> The header is a ‘<samp>;FFMETADATA</samp>’ string, followed by a version number (now 1). + +</li><li> Metadata tags are of the form ‘<samp>key=value</samp>’ + +</li><li> Immediately after header follows global metadata + +</li><li> After global metadata there may be sections with per-stream/per-chapter +metadata. + +</li><li> A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in +brackets (‘<samp>[</samp>’, ‘<samp>]</samp>’) and ends with next section or end of file. + +</li><li> At the beginning of a chapter section there may be an optional timebase to be +used for start/end values. It must be in form +‘<samp>TIMEBASE=<var>num</var>/<var>den</var></samp>’, where <var>num</var> and <var>den</var> are +integers. If the timebase is missing then start/end times are assumed to +be in nanoseconds. + +<p>Next a chapter section must contain chapter start and end times in form +‘<samp>START=<var>num</var></samp>’, ‘<samp>END=<var>num</var></samp>’, where <var>num</var> is a positive +integer. +</p> +</li><li> Empty lines and lines starting with ‘<samp>;</samp>’ or ‘<samp>#</samp>’ are ignored. + +</li><li> Metadata keys or values containing special characters (‘<samp>=</samp>’, ‘<samp>;</samp>’, +‘<samp>#</samp>’, ‘<samp>\</samp>’ and a newline) must be escaped with a backslash ‘<samp>\</samp>’. + +</li><li> Note that whitespace in metadata (e.g. ‘<samp>foo = bar</samp>’) is considered to be +a part of the tag (in the example above key is ‘<samp>foo </samp>’, value is +‘<samp> bar</samp>’). +</li></ol> + +<p>A ffmetadata file might look like this: +</p><div class="example"> +<pre class="example">;FFMETADATA1 +title=bike\\shed +;this is a comment +artist=FFmpeg troll team + +[CHAPTER] +TIMEBASE=1/1000 +START=0 +#chapter ends at 0:01:00 +END=60000 +title=chapter \#1 +[STREAM] +title=multi\ +line +</pre></div> + +<p>By using the ffmetadata muxer and demuxer it is possible to extract +metadata from an input file to an ffmetadata file, and then transcode +the file into an output file with the edited ffmetadata file. +</p> +<p>Extracting an ffmetadata file with <samp>ffmpeg</samp> goes as follows: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE +</pre></div> + +<p>Reinserting edited metadata information from the FFMETADATAFILE file can +be done as: +</p><div class="example"> +<pre class="example">ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT +</pre></div> + + +<a name="See-Also"></a> +<h2 class="chapter">6 See Also<span class="pull-right"><a class="anchor hidden-xs" href="#See-Also" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-See-Also" aria-hidden="true">TOC</a></span></h2> + +<p><a href="ffmpeg.html">ffmpeg</a>, <a href="ffplay.html">ffplay</a>, <a href="ffprobe.html">ffprobe</a>, +<a href="libavformat.html">libavformat</a> +</p> + +<a name="Authors"></a> +<h2 class="chapter">7 Authors<span class="pull-right"><a class="anchor hidden-xs" href="#Authors" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Authors" aria-hidden="true">TOC</a></span></h2> + +<p>The FFmpeg developers. +</p> +<p>For details about the authorship, see the Git history of the project +(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command +<code>git log</code> in the FFmpeg source directory, or browsing the +online repository at <a href="http://source.ffmpeg.org">http://source.ffmpeg.org</a>. +</p> +<p>Maintainers for the specific components are listed in the file +<samp>MAINTAINERS</samp> in the source code tree. +</p> + + <p style="font-size: small;"> + This document was generated using <a href="https://www.gnu.org/software/texinfo/"><em>makeinfo</em></a>. + </p> + </div> + </body> +</html> |