diff options
Diffstat (limited to 'doc/filters.texi')
-rw-r--r-- | doc/filters.texi | 37 |
1 files changed, 14 insertions, 23 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index d83a3fb91e..ffe9a424a8 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -1794,33 +1794,24 @@ Set wet gain. This sets final output gain. Set Impulse Response filter length. Default is 1, which means whole IR is processed. @item gtype -Enable applying gain measured from power of IR. +This option is deprecated, and does nothing. -Set which approach to use for auto gain measurement. +@item irnorm +Set norm to be applied to IR coefficients before filtering. +Allowed range is from @var{-1} to @var{2}. +IR coefficients are normalized with calculated vector norm set by this option. +For negative values, no norm is calculated, and IR coefficients are not modified at all. +Default is @var{1}. -@table @option -@item none -Do not apply any gain. - -@item peak -select peak gain, very conservative approach. This is default value. - -@item dc -select DC gain, limited application. - -@item gn -select gain to noise approach, this is most popular one. - -@item ac -select AC gain. - -@item rms -select RMS gain. -@end table +@item irlink +For multichannel IR if this option is set to @var{true}. All IR channels will be +normalized with maximal measured gain of all IR channels coefficients as set by @code{irnorm} option. +When disabled, all IR coefficients in each IR channel will be normalized independently. +Default is @var{true}. @item irgain Set gain to be applied to IR coefficients before filtering. -Allowed range is 0 to 1. This gain is applied after any gain applied with @var{gtype} option. +Allowed range is 0 to 1. This gain is applied after any gain applied with @var{irnorm} option. @item irfmt Set format of IR stream. Can be @code{mono} or @code{input}. @@ -1899,7 +1890,7 @@ ffmpeg -i input.wav -i middle_tunnel_1way_mono.wav -lavfi afir output.wav Apply true stereo processing given input stereo stream, and two stereo impulse responses for left and right channel, the impulse response files are files with names l_ir.wav and r_ir.wav: @example -"pan=4C|c0=FL|c1=FL|c2=FR|c3=FR[a];amovie=l_ir.wav[LIR];amovie=r_ir.wav[RIR];[LIR][RIR]amerge[ir];[a][ir]afir=irfmt=input:gtype=gn:irgain=-5dB,pan=stereo|FL<c0+c2|FR<c1+c3" +"pan=4C|c0=FL|c1=FL|c2=FR|c3=FR[a];amovie=l_ir.wav[LIR];amovie=r_ir.wav[RIR];[LIR][RIR]amerge[ir];[a][ir]afir=irfmt=input:irgain=-5dB,pan=stereo|FL<c0+c2|FR<c1+c3" @end example @end itemize |