[MPlayer-dev-eng] MPCF Draft/Discussion (MPlayer ContainerFormat)

Fabien Tassin fta+mplayer at sofaraway.org
Fri Feb 7 20:42:32 CET 2003


According to Robert R. Wal:
> 
> > nope. No need to add a stream to have chapters, menu and similar features.
> > Streams are for video, audio and subtitles.
> > Macro blocks are for headers/index/chapters/gadgets and should be at
> > the beginning or at the end, not interleaved.
> > In ASF, chapters are optionals and described in 0 or 1 'marker' object.
> > Scripts are also optionals and described in 1 'script command' object.
> > It is good enough for me.
> 
> Before I read even more brilliant suggestions about groundbreaking
> features of ASF I suggest everyone to google for IFF format
> specification (from mid or early eighties) on which all multimedia
> formats from Microsoft are based[1]. However ego-boosting reinventing
> the wheel may be, it's good to know what _has been_ achieved in
> fileformats realm to this date and what to avoid.

I know that pretty well. I played with that in the late eighties.
More recently, I also wrote a small demuxer for ASF/AVI/RM/MPEG/OGG for
one of my projects so I think I know enough to give my views on that subject.
I do not pretend to know anything better than anyone else.
BTW, I usually don't write specs because they are already there (but
I implemented many).
 
> I'm not suggesting to clone any existing format, just read what's been
> done and choose what worked and what didn't.

Agreed and that's why I tried to give living examples in my previous messages.
Some think that my ideas, and others's, only deserves insults..
(un?)fortunatly it is very common in this list so I don't care much.
 
> Recommended reading:
> 
> http://www.borg.com/~jglatt/tech/aboutiff.htm
> http://www.rahul.net/jfm/avi.html
> http://www.xiph.org/ogg/vorbis/doc/oggstream.html
> http://www.xiph.org/ogg/vorbis/doc/framing.html
> 
> Not recommended reading/inspiration:
> (overly complicated, implementation based instead of solution based
> design and general brain damage)

It is worth the read just to understand what is wrong and why.
> 
> QT/MOV fileformat
> MCF
> Matroska
> 
> Robert
> 
> PS. I'm amazed by multiplicity of broken multimedia formats when after
> reading several specs one realizes that all that is needed is
> some typed-chunk based format with provisions for streaming,
> seeking, error recovery/stream resynchronisation.
> 
> [1] properly written IFF parser from Amiga parses without any trouble
>  WAV and AVI files after you add provisions for reading BE/LE values.
> Bastard Operator From 149.156.96.35

IMHO, IFF is not "specialized" enough. You can virtually describe anything
using IFF but if you add a few rules, you obtain an AVI (never an ASF).

/Fabien


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