[MPlayer-dev-eng] Native codecs from libavcodecs

[Michael Niedermayer]

Hi

On Thursday 09 October 2003 23:48, Roberto Togni wrote:
[...]
> > afair the multiple csp support was finally commited to lavc, but the
> > mplayer
> > side (vd_ffmpeg) was not yet implemented (i mean get_format() or so).
>
> I'm looking into it. get_format is useful only when a codec can output
> a frame in more than one colorspace.
> Most codecs support different colorspaces with the same fourcc: the
> codec will return the right one, and all the available colorspaces will
> be listed in codecs.conf with the "query" flag (just as it's done now).
> As for outputting a frame with a colorspace different from the native
> one, i'd like to support only trivial conversions (example: RGB24 to
> RGB32). Now some codecs supports more colorspaces, but i'd like to
> remove all unnecessary colorspace conversion code from the codecs
> (unless native format is non standard). 
agree

> Sometimes this could hurt
> performance a bit (a codec could do fewer conversions), but since we're
> talking abut stuff designed for a 486 class pc (or even less) i think
> it's not a problem.
>
> I'd expecially like to support only RGB8 for all formats with a palette ,
> and avoid RGB15/16->RGB32 conversions.
>
> Still have to decide what to do with <8bpp formats (RGB4 and
> monochrome),
>
> > you know, lavc is not so strong in rgb/bgr formats, there are unclean
> > things
> > around byteorders and 15 vs 16, and 24 vs 32 bpp formats.
>
> Everyting is stored in cpu endianness except 24bit rgb, that have two
> explicit formats RGB24 and BGR24 :(((
what would u suggest instead (and why) ? these formats arent used much yet in 
libavcodec so we could still change them 

[...]
-- 
Michael
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