[FFmpeg-devel] [PATCH] avfilter: port qp filter from libmpcodecs

[Stefano Sabatini]

On date Wednesday 2013-09-18 18:34:36 +0000, Paul B Mahol encoded:
> Signed-off-by: Paul B Mahol <onemda at 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
>  
> + at 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

> + at table @option
> + at item qp
> +Set expression for quantization parameter.
> + at end table
> +
> +The expression is evaluated through the eval API and can contain, among others,
> +the following constants:
> +
> + at table @option

Nit: @table @var

> + at item known
> +1 if index is not 129, 0 otherwise.
> +
> + at item qp
> +Sequentional index starting from -129 to 128.
> + at end table
> +
> + at subsection Examples
> +
> + at itemize
> + at item
> +Some equatition like:

equation

> + at example
> +qp=2+2*sin(PI*qp)
> + at end example

Some meaningful examples are sorely needed.

[...]
-- 
FFmpeg = Funny & Fiendish Mega Practical Energized Guru