From f5c4671bfbad96bf346bd7e9a21fc4317b4959df Mon Sep 17 00:00:00 2001 From: Indrajith K L Date: Sat, 3 Dec 2022 17:00:20 +0530 Subject: Adds most of the tools --- ffmpeg/doc/ffmpeg-resampler.html | 364 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 364 insertions(+) create mode 100644 ffmpeg/doc/ffmpeg-resampler.html (limited to 'ffmpeg/doc/ffmpeg-resampler.html') diff --git a/ffmpeg/doc/ffmpeg-resampler.html b/ffmpeg/doc/ffmpeg-resampler.html new file mode 100644 index 0000000..8a11b08 --- /dev/null +++ b/ffmpeg/doc/ffmpeg-resampler.html @@ -0,0 +1,364 @@ + + + + + + + FFmpeg Resampler Documentation + + + + + + +
+

+ FFmpeg Resampler Documentation +

+
+
+ + + + +
+

Table of Contents

+ +
+ + +
+
+ + +

1 Description

+ +

The FFmpeg resampler provides a high-level interface to the +libswresample library audio resampling utilities. In particular it +allows one to perform audio resampling, audio channel layout rematrixing, +and convert audio format and packing layout. +

+ + +

2 Resampler Options

+ +

The audio resampler supports the following named options. +

+

Options may be set by specifying -option value in the +FFmpeg tools, option=value for the aresample filter, +by setting the value explicitly in the +SwrContext options or using the libavutil/opt.h API for +programmatic use. +

+
+
ich, in_channel_count
+

Set the number of input channels. Default value is 0. Setting this +value is not mandatory if the corresponding channel layout +in_channel_layout is set. +

+
+
och, out_channel_count
+

Set the number of output channels. Default value is 0. Setting this +value is not mandatory if the corresponding channel layout +out_channel_layout is set. +

+
+
uch, used_channel_count
+

Set the number of used input channels. Default value is 0. This option is +only used for special remapping. +

+
+
isr, in_sample_rate
+

Set the input sample rate. Default value is 0. +

+
+
osr, out_sample_rate
+

Set the output sample rate. Default value is 0. +

+
+
isf, in_sample_fmt
+

Specify the input sample format. It is set by default to none. +

+
+
osf, out_sample_fmt
+

Specify the output sample format. It is set by default to none. +

+
+
tsf, internal_sample_fmt
+

Set the internal sample format. Default value is none. +This will automatically be chosen when it is not explicitly set. +

+
+
icl, in_channel_layout
+
ocl, out_channel_layout
+

Set the input/output channel layout. +

+

See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual +for the required syntax. +

+
+
clev, center_mix_level
+

Set the center mix level. It is a value expressed in deciBel, and must be +in the interval [-32,32]. +

+
+
slev, surround_mix_level
+

Set the surround mix level. It is a value expressed in deciBel, and must +be in the interval [-32,32]. +

+
+
lfe_mix_level
+

Set LFE mix into non LFE level. It is used when there is a LFE input but no +LFE output. It is a value expressed in deciBel, and must +be in the interval [-32,32]. +

+
+
rmvol, rematrix_volume
+

Set rematrix volume. Default value is 1.0. +

+
+
rematrix_maxval
+

Set maximum output value for rematrixing. +This can be used to prevent clipping vs. preventing volume reduction. +A value of 1.0 prevents clipping. +

+
+
flags, swr_flags
+

Set flags used by the converter. Default value is 0. +

+

It supports the following individual flags: +

+
res
+

force resampling, this flag forces resampling to be used even when the +input and output sample rates match. +

+
+ +
+
dither_scale
+

Set the dither scale. Default value is 1. +

+
+
dither_method
+

Set dither method. Default value is 0. +

+

Supported values: +

+
‘rectangular’
+

select rectangular dither +

+
‘triangular’
+

select triangular dither +

+
‘triangular_hp’
+

select triangular dither with high pass +

+
‘lipshitz’
+

select Lipshitz noise shaping dither. +

+
‘shibata’
+

select Shibata noise shaping dither. +

+
‘low_shibata’
+

select low Shibata noise shaping dither. +

+
‘high_shibata’
+

select high Shibata noise shaping dither. +

+
‘f_weighted’
+

select f-weighted noise shaping dither +

+
‘modified_e_weighted’
+

select modified-e-weighted noise shaping dither +

+
‘improved_e_weighted’
+

select improved-e-weighted noise shaping dither +

+
+
+ +
+
resampler
+

Set resampling engine. Default value is swr. +

+

Supported values: +

+
‘swr’
+

select the native SW Resampler; filter options precision and cheby are not +applicable in this case. +

+
‘soxr’
+

select the SoX Resampler (where available); compensation, and filter options +filter_size, phase_shift, exact_rational, filter_type & kaiser_beta, are not +applicable in this case. +

+
+ +
+
filter_size
+

For swr only, set resampling filter size, default value is 32. +

+
+
phase_shift
+

For swr only, set resampling phase shift, default value is 10, and must be in +the interval [0,30]. +

+
+
linear_interp
+

Use linear interpolation when enabled (the default). Disable it if you want +to preserve speed instead of quality when exact_rational fails. +

+
+
exact_rational
+

For swr only, when enabled, try to use exact phase_count based on input and +output sample rate. However, if it is larger than 1 << phase_shift, +the phase_count will be 1 << phase_shift as fallback. Default is enabled. +

+
+
cutoff
+

Set cutoff frequency (swr: 6dB point; soxr: 0dB point) ratio; must be a float +value between 0 and 1. Default value is 0.97 with swr, and 0.91 with soxr +(which, with a sample-rate of 44100, preserves the entire audio band to 20kHz). +

+
+
precision
+

For soxr only, the precision in bits to which the resampled signal will be +calculated. The default value of 20 (which, with suitable dithering, is +appropriate for a destination bit-depth of 16) gives SoX’s ’High Quality’; a +value of 28 gives SoX’s ’Very High Quality’. +

+
+
cheby
+

For soxr only, selects passband rolloff none (Chebyshev) & higher-precision +approximation for ’irrational’ ratios. Default value is 0. +

+
+
async
+

For swr only, simple 1 parameter audio sync to timestamps using stretching, +squeezing, filling and trimming. Setting this to 1 will enable filling and +trimming, larger values represent the maximum amount in samples that the data +may be stretched or squeezed for each second. +Default value is 0, thus no compensation is applied to make the samples match +the audio timestamps. +

+
+
first_pts
+

For swr only, assume the first pts should be this value. The time unit is 1 / sample rate. +This allows for padding/trimming at the start of stream. By default, no +assumption is made about the first frame’s expected pts, so no padding or +trimming is done. For example, this could be set to 0 to pad the beginning with +silence if an audio stream starts after the video stream or to trim any samples +with a negative pts due to encoder delay. +

+
+
min_comp
+

For swr only, set the minimum difference between timestamps and audio data (in +seconds) to trigger stretching/squeezing/filling or trimming of the +data to make it match the timestamps. The default is that +stretching/squeezing/filling and trimming is disabled +(min_comp = FLT_MAX). +

+
+
min_hard_comp
+

For swr only, set the minimum difference between timestamps and audio data (in +seconds) to trigger adding/dropping samples to make it match the +timestamps. This option effectively is a threshold to select between +hard (trim/fill) and soft (squeeze/stretch) compensation. Note that +all compensation is by default disabled through min_comp. +The default is 0.1. +

+
+
comp_duration
+

For swr only, set duration (in seconds) over which data is stretched/squeezed +to make it match the timestamps. Must be a non-negative double float value, +default value is 1.0. +

+
+
max_soft_comp
+

For swr only, set maximum factor by which data is stretched/squeezed to make it +match the timestamps. Must be a non-negative double float value, default value +is 0. +

+
+
matrix_encoding
+

Select matrixed stereo encoding. +

+

It accepts the following values: +

+
‘none’
+

select none +

+
‘dolby’
+

select Dolby +

+
‘dplii’
+

select Dolby Pro Logic II +

+
+ +

Default value is none. +

+
+
filter_type
+

For swr only, select resampling filter type. This only affects resampling +operations. +

+

It accepts the following values: +

+
‘cubic’
+

select cubic +

+
‘blackman_nuttall’
+

select Blackman Nuttall windowed sinc +

+
‘kaiser’
+

select Kaiser windowed sinc +

+
+ +
+
kaiser_beta
+

For swr only, set Kaiser window beta value. Must be a double float value in the +interval [2,16], default value is 9. +

+
+
output_sample_bits
+

For swr only, set number of used output sample bits for dithering. Must be an integer in the +interval [0,64], default value is 0, which means it’s not used. +

+
+
+ + + +

3 See Also

+ +

ffmpeg, ffplay, ffprobe, +libswresample +

+ + +

4 Authors

+ +

The FFmpeg developers. +

+

For details about the authorship, see the Git history of the project +(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command +git log in the FFmpeg source directory, or browsing the +online repository at http://source.ffmpeg.org. +

+

Maintainers for the specific components are listed in the file +MAINTAINERS in the source code tree. +

+ +

+ This document was generated using makeinfo. +

+
+ + -- cgit v1.2.3