mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2024-12-29 10:52:20 +00:00
201 lines
4.8 KiB
Plaintext
201 lines
4.8 KiB
Plaintext
\input texinfo @c -*- texinfo -*-
|
|
|
|
@settitle FFmpeg Resampler Documentation
|
|
@titlepage
|
|
@center @titlefont{FFmpeg Resampler Documentation}
|
|
@end titlepage
|
|
|
|
@top
|
|
|
|
@contents
|
|
|
|
@chapter Description
|
|
@c man begin DESCRIPTION
|
|
|
|
The FFmpeg resampler provides an high-level interface to the
|
|
libswresample library audio resampling utilities. In particular it
|
|
allows to perform audio resampling, audio channel layout rematrixing,
|
|
and convert audio format and packing layout.
|
|
|
|
@c man end DESCRIPTION
|
|
|
|
@chapter Resampler Options
|
|
@c man begin RESAMPLER OPTIONS
|
|
|
|
The audio resampler supports the following named options.
|
|
|
|
Options may be set by specifying -@var{option} @var{value} in the
|
|
FFmpeg tools, @var{option}=@var{value} for the aresample filter,
|
|
by setting the value explicitly in the
|
|
@code{SwrContext} options or using the @file{libavutil/opt.h} API for
|
|
programmatic use.
|
|
|
|
@table @option
|
|
|
|
@item 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
|
|
@option{in_channel_layout} is set.
|
|
|
|
@item 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
|
|
@option{out_channel_layout} is set.
|
|
|
|
@item uch, used_channel_count
|
|
Set the number of used channels. Default value is 0. This option is
|
|
only used for special remapping.
|
|
|
|
@item isr, in_sample_rate
|
|
Set the input sample rate. Default value is 0.
|
|
|
|
@item osr, out_sample_rate
|
|
Set the output sample rate. Default value is 0.
|
|
|
|
@item isf, in_sample_fmt
|
|
Specify the input sample format. It is set by default to @code{none}.
|
|
|
|
@item osf, out_sample_fmt
|
|
Specify the output sample format. It is set by default to @code{none}.
|
|
|
|
@item tsf, internal_sample_fmt
|
|
Set the internal sample format. Default value is @code{none}.
|
|
|
|
@item icl, in_channel_layout
|
|
Set the input channel layout.
|
|
|
|
@item ocl, out_channel_layout
|
|
Set the output channel layout.
|
|
|
|
@item clev, center_mix_level
|
|
Set center mix level. It is a value expressed in deciBel, and must be
|
|
inclusively included between -32 and +32.
|
|
|
|
@item slev, surround_mix_level
|
|
Set surround mix level. It is a value expressed in deciBel, and must
|
|
be inclusively included between -32 and +32.
|
|
|
|
@item lfe_mix_evel
|
|
Set LFE mix level.
|
|
|
|
@item rmvol, rematrix_volume
|
|
Set rematrix volume. Default value is 1.0.
|
|
|
|
@item flags, swr_flags
|
|
Set flags used by the converter. Default value is 0.
|
|
|
|
It supports the following individual flags:
|
|
@table @option
|
|
@item res
|
|
force resampling
|
|
@end table
|
|
|
|
@item dither_scale
|
|
Set the dither scale. Default value is 1.
|
|
|
|
@item dither_method
|
|
Set dither method. Default value is 0.
|
|
|
|
Supported values:
|
|
@table @samp
|
|
@item rectangular
|
|
select rectangular dither
|
|
@item triangular
|
|
select triangular dither
|
|
@item triangular_hp
|
|
select triangular dither with high pass
|
|
@end table
|
|
|
|
@item filter_size
|
|
Set resampling filter size, default value is 16.
|
|
|
|
@item phase_shift
|
|
Set resampling phase shift, default value is 10, must be included
|
|
between 0 and 30.
|
|
|
|
@item linear_interp
|
|
Use Linear Interpolation if set to 1, default value is 0.
|
|
|
|
@item cutoff
|
|
Set cutoff frequency ratio. Must be a float value between 0 and 1,
|
|
default value is 0.8.
|
|
|
|
@item min_comp
|
|
Set minimum difference between timestamps and audio data (in seconds)
|
|
below which no timestamp compensation of either kind is applied.
|
|
Default value is @code{FLT_MAX}.
|
|
|
|
@item min_hard_comp
|
|
Set minimum difference between timestamps and audio data (in seconds)
|
|
to trigger padding/trimming the data. Must be a non-negative double,
|
|
default value is 0.1.
|
|
|
|
@item comp_duration
|
|
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.
|
|
|
|
@item max_soft_comp
|
|
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.
|
|
|
|
@item matrix_encoding
|
|
Select matrixed stereo encoding.
|
|
|
|
It accepts the following values:
|
|
@table @samp
|
|
@item none
|
|
select none
|
|
@item dolby
|
|
select Dolby
|
|
@item dplii
|
|
select Dolby Pro Logic II
|
|
@end table
|
|
|
|
Default value is @code{none}.
|
|
|
|
@item filter_type
|
|
Select resampling filter type. This only affects resampling
|
|
operations.
|
|
|
|
It accepts the following values:
|
|
@table @samp
|
|
@item cubic
|
|
select cubic
|
|
@item blackman_nuttall
|
|
select Blackman Nuttall Windowed Sinc
|
|
@item kaiser
|
|
select Kaiser Windowed Sinc
|
|
@end table
|
|
|
|
@item kaiser_beta
|
|
Set Kaiser Window Beta value. Must be an integer included between 2
|
|
and 16, default value is 9.
|
|
|
|
@end table
|
|
|
|
@c man end RESAMPLER OPTIONS
|
|
|
|
@chapter See Also
|
|
|
|
@ifhtml
|
|
@url{ffmpeg.html,ffmpeg}, @url{ffplay.html,ffplay}, @url{ffprobe.html,ffprobe}, @url{ffserver.html,ffserver},
|
|
@url{libswresample.html}
|
|
@end ifhtml
|
|
|
|
@ifnothtml
|
|
ffmpeg(1), ffplay(1), ffprobe(1), ffserver(1), libswresample(3)
|
|
@end ifnothtml
|
|
|
|
@include authors.texi
|
|
|
|
@ignore
|
|
|
|
@setfilename ffmpeg-resampler
|
|
@settitle FFmpeg Resampler
|
|
|
|
@end ignore
|
|
|
|
@bye
|