[MPlayer-dev-eng] MCF ( Multimedia Container Format ) : Invitation to participate

[Felix Buenemann]

On Monday 03 June 2002 00:12, Christian HJ Wiesner wrote:
> While the basic data and block structure is fixed now and already
> implemented in libmcf on CVS we are currently in the phase of deciding how
> to support all the different codecs and formats. Easiest thing to do what
> of course be to use the M$ dshow method of building a playback graph based
> on the FourCC of the use codec. But as we are ware that this may cause
> problem on other OS such as Linux or MacOS we were discussing alternative
> solutions like a plugin structure ( f.e. a MPEG4 ISO video plugin to play
> XviD and DivX5 ).
I don't see where choosing the right video codec has anything to do with the 
file format. The only thing the file format has to signal is, what codec is 
used, the player can then use this info to choose the right decoder. Mostly 
FOURCC would be enough for this, maybe an extra field that gives the long 
name of the codec. And a thought would be to use 8 or 16 char codec 
identifier, as four char seems to get close to it's limit with all those 
different codecs out there. Exisitng codecs could use their FOURCC padded 
with spaces to the new identifier size.
Also you should add a field to store codec specific data, this is eg. needed 
to store the mpeg4 video headers.

All this was written out-of-the-blue, I haven't looked at the MCF specs yet.

>
> Mplayer is currently the only Linux player that is capable of playing back
> .ogm files, so we are very interested how you managed to get this working.
> Is it possible to have dshow based parsers/decoders working on Linux ?
We don't use the windows code, we have an own implementation of the ogm 
demuxer.

Btw. we can even use windows dshow codecs through our dshow emulation layer 
which is based on wine (code is inherited from aviplay project).

> Also
> we are convinced that the discussion between mplayer developers and our
> people could lead to a very good cooperation for both sides. Good old AVI
> has definitely seen the end of its days, but we are not convinced that the
> existing Ogg implementation is the answer to this. We hope MCF could raise
> your interest and look forward to your precious input.
Yes, the ogg format wasn't at all aimed at video from the beginning, so it's 
pretty much a hack/suboptimal from what I can see/have heard.

> Please contact us on IRC, openprojects, #mcf to discuss how we could best
> implement codec/formats support into MCF.
This would probably be a job for our demuxer-experts like AAA (arpi,al3x,albeu 
;-) and the ones I forgot. I did some demuxer hacking in mplayer, but I'm no 
demuxer expert at all.

Btw. as arpi is lazy ;) it would probably be a better idea to visit us on 
#MPlayerDEV in ircnet (irc.netsurf.de and others).

Or best thing keep the discussion on the mailinglist, this is the best way, as 
it allows all people to take part in the discussion and decisions. IRC is 
more meant for quick-questions stuff.

-- 
Best Regards,
        Atmos
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