On date Wednesday 2013-09-18 18:34:36 +0000, Paul B Mahol encoded:
Signed-off-by: Paul B Mahol <onemda@gmail.com> --- doc/filters.texi | 32 ++++++++++ libavfilter/Makefile | 1 + libavfilter/allfilters.c | 1 + libavfilter/vf_qp.c | 154 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 188 insertions(+) create mode 100644 libavfilter/vf_qp.c
diff --git a/doc/filters.texi b/doc/filters.texi index 915f310..e7cac2d 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -6236,6 +6236,38 @@ The main purpose of setting @option{mp} to a chroma plane is to reduce CPU load and make pullup usable in realtime on slow machines. @end table
+@section qp + +Quantization Parameter (QP) change filter.
Change video quantization parameters (QP). Possibly state why/how is this useful (MPlayer docs are pretty sparse on it).
+
+The filter accepts the following option:
options
+@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 @option
Nit: @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 equatition like:
equation
+@example +qp=2+2*sin(PI*qp) +@end example
Some meaningful examples are sorely needed. [...] -- FFmpeg = Funny & Fiendish Mega Practical Energized Guru