[FFmpeg-devel] Selective video compression qualities

[Aviv Hurvitz]

Thanks for your answers.

In my search across the web, I found the following commit to the x264
source code that I believe will do what I want.

See function
 x264_adaptive_quant_frame()

http://git.videolan.org/gitweb.cgi/x264.git/?a=commit;h=a6c6afa85053443dc459e096e8e681dc21d43ade

Michael, would you say I'm on the right track? I'm sorry if the question is
very basic, I just learned what MB and QP mean a few days ago :)

Also has anyone had experience with doing this ROI-specific QP setting and
would care to give me pointers and/or source code ?

Many thanks!


On Tue, Sep 3, 2013 at 2:34 AM, Michael Niedermayer <michaelni at gmx.at>wrote:

> On Mon, Sep 02, 2013 at 05:02:44PM -0400, compn wrote:
> > On Mon, 2 Sep 2013 17:27:33 +0200, Michael Niedermayer wrote:
> > >On Mon, Sep 02, 2013 at 01:49:08PM +0300, Aviv Hurvitz wrote:
> > >> Hi all,
> > >>
> > >> I am interested in encoding a compressed video of a basketball game,
> > >> wherein the players are compressed in high quality (high bitrate) and
> the
> > >> rest of the image (the crowds, the court) uses a lesser quality. I
> already
> > >> have a binary mask that indicates which parts of the video I would
> like to
> > >> retain in high quality.
> > >>
> > >> I'd be grateful for for any advice on achieving this. Are there any
> video
> > >> codecs that support this feature? Which would be the best fit if I
> want to
> > >> develop it myself?
> > >
> > >any video codec that can change the QP per MB could be used, that
> > >means pretty much any modern video codec
> >
> > i bet he wants to know how to do it :)
> >
> > isnt that custom matrices? or Quantization Matrix
>
> no
>
> one has to modify the quantiztaion parameter for the macroblocks
> depending on whats in the block, thats more like what xvid lumi
> masking did. But instead of using some brightness of the block use
> a externally provided mask
>
> [...]
> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> Awnsering whenever a program halts or runs forever is
> On a turing machine, in general impossible (turings halting problem).
> On any real computer, always possible as a real computer has a finite
> number
> of states N, and will either halt in less than N cycles or never halt.
>
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