[FFmpeg-devel] [PATCH] attachments support in matroska demuxer

Reimar Döffinger Reimar.Doeffinger
Sun Jan 20 20:31:12 CET 2008

On Sun, Jan 20, 2008 at 08:09:32PM +0100, Baptiste Coudurier wrote:
> Reimar D?ffinger wrote:
> > On Sun, Jan 20, 2008 at 06:35:58PM +0000, M?ns Rullg?rd wrote:
> >> Michael Niedermayer <michaelni at gmx.at> writes:
> > [...]
> >>>     } else if (startcode >= 0x1c0 && startcode <= 0x1df) {
> >>>         type = CODEC_TYPE_AUDIO;
> >>>         codec_id = m->sofdec > 0 ? CODEC_ID_ADPCM_ADX : CODEC_ID_MP2;
> >> It's not the fault of MPEG that whoever is behind ADX chose to ignore
> >> the spec.
> >>
> >>> avi doesnt have such entertaining identifer system, but uses boring 4 
> >>> character codes with some similarity to the codec name and suprisingly
> >>> that anarchistic system is free of colissions while the great mpeg
> >>> is full of collisions.
> >> Well, with AVI the problem is the opposite.  Every codec has a zillion
> >> different identifiers.
> > 
> > It's not the fault of AVI that whoever is behind those chose to ignore
> > the spec...
> Why didn't they drop avi and choose/design a correct one before hacking it ?

Well, some hacks were just because some _players_ has stupid
restrictions, how would choosing better format help (except that there
are no players at all that would play it, so yes supporting outdated
players is not an issue then)?
Some issues are because some people did not like the spec and just
decided to do it their way. That's something you can blame the spec at
most partially for, and as proven all the time that affects all specs...
And then a good deal of the issues are because loads of people write AVI
muxers without even reading the spec. I seriously doubt that MOV or MPEG
or whatever would fare even the slightest bit against this kind of
"attack". Actually MPEG has enough problems to deal with the mess that
so-called standards-organizations make of it...
And then comes the part of true problems with AVI. Most people IMO will
never come over those because they just do not need them. Nevertheless
they are good reason to replace AVI.
Though the question is with what? So far the only contender that is not
completely laden with hacks yet is mkv, though it has its ugliness in
abundance as well. And I'm not at all certain what horrors we will see
if it ever reaches the usage level of AVI...

> It's either a container evolves to support more things (mov), or is
> being discontinued (avi), which is what MS did, but you guys wants to
> stick forever with it, just let it go...

I don't want to stick with AVI, not at all. And in case you haven't
noticed I only mocked Mans' way of excusing the problems MPEG has by
excusing AVI's in the same way.
Either way, attacking and defending AVI is quite pointless when the
issue is actually an API issue, and the question is how to provide a way
that allows a lavf user to detect and use a codec format that lavc has
clue about.

Reimar D?ffinger

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