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Diffstat (limited to 'doc/filters.texi')
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diff --git a/doc/filters.texi b/doc/filters.texi index 42f69eaacb..154508cfff 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -7351,6 +7351,38 @@ telecine NTSC input: ffmpeg -i input -vf pullup -r 24000/1001 ... @end example +@section qp + +Change video quantization parameters (QP). + +The filter accepts the following option: + +@table @option +@item qp +Set expression for quantization parameter. +@end table + +The expression is evaluated through the eval API and can contain, among others, +the following constants: + +@table @var +@item known +1 if index is not 129, 0 otherwise. + +@item qp +Sequentional index starting from -129 to 128. +@end table + +@subsection Examples + +@itemize +@item +Some equation like: +@example +qp=2+2*sin(PI*qp) +@end example +@end itemize + @section removelogo Suppress a TV station logo, using an image file to determine which |