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author | Paul B Mahol <onemda@gmail.com> | 2016-08-10 16:11:37 +0200 |
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committer | Paul B Mahol <onemda@gmail.com> | 2016-08-11 15:02:16 +0200 |
commit | 7f1b14bc5730bd5603dda57302d4adad94ccdd60 (patch) | |
tree | bb98e471cc6cde00dbcc964e9df72e73350a0f92 /doc | |
parent | cc6a59d2b9116a4084275bbb8634862ddd14ec56 (diff) |
avfilter: add acrusher filter
Diffstat (limited to 'doc')
-rw-r--r-- | doc/filters.texi | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index 9dab959bdb..8bb0ca00ca 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -441,6 +441,64 @@ ffmpeg -i first.flac -i second.flac -filter_complex acrossfade=d=10:o=0:c1=exp:c @end example @end itemize +@section acrusher + +Reduce audio bit resolution. + +This filter is bit crusher with enhanced funcionality. A bit crusher +is used to audibly reduce number of bits an audio signal is sampled +with. This doesn't change the bit depth at all, it just produces the +effect. Material reduced in bit depth sounds more harsh and "digital". +This filter is able to even round to continous values instead of discrete +bit depths. +Additionally it has a D/C offset which results in different crushing of +the lower and the upper half of the signal. +An Anti-Aliasing setting is able to produce "softer" crushing sounds. + +Another feature of this filter is the logarithmic mode. +This setting switches from linear distances between bits to logarithmic ones. +The result is a much more "natural" sounding crusher which doesn't gate low +signals for example. The human ear has a logarithmic perception, too +so this kind of crushing is much more pleasant. +Logarithmic crushing is also able to get anti-aliased. + +The filter accepts the following options: + +@table @option +@item level_in +Set level in. + +@item level_out +Set level out. + +@item bits +Set bit reduction. + +@item mix +Set mixing ammount. + +@item mode +Can be linear: @code{lin} or logarithmic: @code{log}. + +@item dc +Set DC. + +@item aa +Set anti-aliasing. + +@item samples +Set sample reduction. + +@item lfo +Enable LFO. By default disabled. + +@item lforange +Set LFO range. + +@item lforate +Set LFO rate. +@end table + @section adelay Delay one or more audio channels. |