[FFmpeg-devel] [RFC] libswscale palette output implementation

[Kostya]

On Thu, Dec 31, 2009 at 05:28:24PM +0100, Stefano Sabatini wrote:
> Hi,
> 
> related thread:
> http://thread.gmane.org/gmane.comp.video.ffmpeg.devel/80845/focus=82531
> 
> Kostya's idea is to use Vitor's ELBG implementation in
> libavcodec/elbg.{h,c}, first step would be to move it to lavu where it
> can be used by lsws. This shouldn't comport any ABI / API issues,
> since the API is only internal (it would only require a dependancy
> change of lavc on lavu, but I may be wrong here).

Just don't forget one point (I may be wrong here though): scale code may
be called on slice or single line, so you need somehow to ensure it
processes the whole picture. Maybe just having single filter for that is
better. Also it may be improved to produce palette with minimum
differences for consequent frames, etc.

> Now I'm not sure if Michael would approve such an implementation as he
> has some reservations on that idea, also now I'm reading the paper and
> since I don't have a good background on it it would require some time if
> I'll go for it.

You can alternatively borrow code from pnmquant.