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author | Stefano Sabatini <stefasab@gmail.com> | 2012-12-08 12:07:03 +0100 |
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committer | Stefano Sabatini <stefasab@gmail.com> | 2012-12-08 15:40:07 +0100 |
commit | 10db70d5e9c92f0464089476694d9a440cdac321 (patch) | |
tree | 4dfa17670afb93b371a339d22c7830c1966d6a35 /doc | |
parent | 759e7a237fb60a5a0a157921867fcb73d90e2c53 (diff) | |
download | ffmpeg-10db70d5e9c92f0464089476694d9a440cdac321.tar.gz |
lavfi: drop af_volume_stefano.c in favor of af_volume_justin.c
Justin's version has more features but is otherwise equivalent from the
point of view of the syntax.
Diffstat (limited to 'doc')
-rw-r--r-- | doc/filters.texi | 66 |
1 files changed, 11 insertions, 55 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index 8e70cdb357..56a213ccc6 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -829,56 +829,6 @@ out Convert the audio sample format, sample rate and channel layout. This filter is not meant to be used directly. -@section volume - -Adjust the input audio volume. - -The filter accepts exactly one parameter @var{vol}, which expresses -how the audio volume will be increased or decreased. - -Output values are clipped to the maximum value. - -If @var{vol} is expressed as a decimal number, the output audio -volume is given by the relation: -@example -@var{output_volume} = @var{vol} * @var{input_volume} -@end example - -If @var{vol} is expressed as a decimal number followed by the string -"dB", the value represents the requested change in decibels of the -input audio power, and the output audio volume is given by the -relation: -@example -@var{output_volume} = 10^(@var{vol}/20) * @var{input_volume} -@end example - -Otherwise @var{vol} is considered an expression and its evaluated -value is used for computing the output audio volume according to the -first relation. - -Default value for @var{vol} is 1.0. - -@subsection Examples - -@itemize -@item -Half the input audio volume: -@example -volume=0.5 -@end example - -The above example is equivalent to: -@example -volume=1/2 -@end example - -@item -Decrease input audio power by 12 decibels: -@example -volume=-12dB -@end example -@end itemize - @section volumedetect Detect the volume of the input video. @@ -919,7 +869,7 @@ There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc. In other words, raising the volume by +4 dB does not cause any clipping, raising it by +5 dB causes clipping for 6 samples, etc. -@section volume_justin +@section volume Adjust the input audio volume. @@ -966,15 +916,21 @@ precision of the volume scaling. @item Halve the input audio volume: @example -volume_justin=volume=0.5 -volume_justin=volume=1/2 -volume_justin=volume=-6.0206dB +volume=volume=0.5 +volume=volume=1/2 +volume=volume=-6.0206dB +@end example + +In all the above example the named key for @option{volume} can be +omitted, for example like in: +@example +volume=0.5 @end example @item Increase input audio power by 6 decibels using fixed-point precision: @example -volume_justin=volume=6dB:precision=fixed +volume=volume=6dB:precision=fixed @end example @end itemize |