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author | Paul B Mahol <onemda@gmail.com> | 2017-01-26 17:03:08 +0100 |
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committer | Paul B Mahol <onemda@gmail.com> | 2017-05-09 20:47:52 +0200 |
commit | 49bbfb9d13936ee8bb7fee9983ca3710dc683a2e (patch) | |
tree | f132a0d6a8f1dc1b06e76725eca90fbfb248bc06 /doc | |
parent | f1a4dd5e480932ee580fb686988599d46bb71637 (diff) |
avfilter: add arbitrary audio FIR filter
Signed-off-by: Paul B Mahol <onemda@gmail.com>
Diffstat (limited to 'doc')
-rw-r--r-- | doc/filters.texi | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index 3739fbcc04..c54f5f2dcd 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -878,6 +878,49 @@ afftfilt="1-clip((b/nb)*b,0,1)" @end example @end itemize +@section afir + +Apply an arbitrary Frequency Impulse Response filter. + +This filter is designed for applying long FIR filters, +up to 30 seconds long. + +It can be used as component for digital crossover filters, +room equalization, cross talk cancellation, wavefield synthesis, +auralization, ambiophonics and ambisonics. + +This filter uses second stream as FIR coefficients. +If second stream holds single channel, it will be used +for all input channels in first stream, otherwise +number of channels in second stream must be same as +number of channels in first stream. + +It accepts the following parameters: + +@table @option +@item dry +Set dry gain. This sets input gain. + +@item wet +Set wet gain. This sets final output gain. + +@item length +Set Impulse Response filter length. Default is 1, which means whole IR is processed. + +@item again +Enable applying gain measured from power of IR. +@end table + +@subsection Examples + +@itemize +@item +Apply reverb to stream using mono IR file as second input, complete command using ffmpeg: +@example +ffmpeg -i input.wav -i middle_tunnel_1way_mono.wav -lavfi afir output.wav +@end example +@end itemize + @anchor{aformat} @section aformat |