[Ffmpeg-devel] integrating AVS decoding into MPlayer

Måns Rullgård mru
Sat Jul 15 00:15:29 CEST 2006


Reimar D?ffinger <Reimar.Doeffinger at stud.uni-karlsruhe.de> writes:

> Hello,
> On Fri, Jul 14, 2006 at 09:50:32PM +0100, M?ns Rullg?rd wrote:
>> it in tcvp required very little effort.  All I had to do was teach the
>> mpeg demuxer to detect it and set the codec of such streams to
>> "video/cavs" (or use lavf). 
>
> Well, MPlayer would first set the "id/fourcc" to e.g. CAVS, and then map
> that to the codec.
> The problem here only was that with demux_lavf it relies on some
> libavformat stuff to set the "fourcc", which the author obviously
> thought to be for this use but (according to you) is not.

I always thought that table was for mapping lavc CodecID to and from
32-bit codes used *in AVI files*.  Relying on that table to map
between CodecID and internal identifiers seems wrong to me.  Sure,
most codecs seem to have been used in AVI at least once, so the
chances of finding a match are good, but IMHO should not be relied on.

> Splitting the codec_bmp_tags in two parts with one located in
> MPlayer's demux_lavf.c would probably be two lines of code, but I don't
> like what seems to me "let's decide at random which ids go into
> codec_bmp_tags and which don't".
>
>> That and compile lavc with AVS support.
>> Since lavc advertises the supported codecs by name, it is
>
> Of course that is one useless step if you only want to support
> libavcodec (or at least only one codec per format).

TCVP is generic, and supports several implementations of some codecs,
although it does rely much on lavc.

-- 
M?ns Rullg?rd
mru at inprovide.com




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