[NUT-devel] Codec id - random notes

[Ivan Kalvachev]

2006/6/27, Michael Niedermayer <michaelni at gmx.at>:
> Hi
>
> On Tue, Jun 27, 2006 at 04:00:26PM -0400, Rich Felker wrote:
> [...]
> > > a: adopt a single existing id system like the one from avi or mov
> > > b: like a but remap a few ids we dont like due to philosophical reasons
> > > i: design our own indepenant system for per format ids (no implemtation id)
> > >
> > >
> > >                                 A   I   IA  AA  IAA a-avi   a-mov   b   i   AAA
> > > supports old divx/xvid streams: X   X   X   X   X   X                       X
> > > AVI->NUT->AVI wont change 4cc:  X   X   X   X   X   X                       X
> > > MOV->NUT->MOV wont change 4cc:  X   X   X   X   X           X               X
> > > no table maintaince:            X           X       X       X       x       X
> > > decoder can use existing tables:X       X   X   x   X       X               X
> > > decoder needs single nut-table:     X   X       X   X       X       X   X   X
> > > encoder doesnt need to remap id:X           X                       x
> >
> > To me, the critical ones are:
> > - no table maintaince
> > - using existing tables or existing tables with a few minor additions
> >
> > IMO "encoder doesnt need to remap id" is odd, maybe this means
> > "remuxer from other format doesn't need to remap id"?
>
> yes
>
>
> [...]
> > > a-avi vs. a-mov
> > >     there are more avi fourccs then mov fourccs so IMHO a-avi would be
> > >     a better choice, theres also the old xvid/divx advantage, IIRC theres
> > >     no distinction between the 2 in mov, so IMHO we can drop a-mov
> > > b vs. a-avi
> > >     b is philsophical better at the cost of playability of a very small number
> > >     of divx & xvid videos and it needs a little more maintainance so IMHO
> > >     we can drop b in favor of a-avi
> > > i vs I
> > >     if we are really building our own format id table then i guess a field
> > >     more for the implemenattion wont hurt so IMHO drop i
> > > AA vs. AAA
> > >     AA has a big problem, the nut file could use any id system, so this
> > >     moves alot of complexity to the demuxer, so i belive its not
> > >     controversical if i drop it in favor of some other system like AAA
> > >     or another one which does the remaping at the muxer side
> >
> > If the avi-style fourcc is required, it seems a bit odd to have other
> > format ids too. Any demuxer implementation will have to be able to
> > read the avi fourcc (in case it's the only one there), so what's the
> > good of having more ids?
> >
> > The only way I find the AAA option interesting is if we require one of
> > the ids to refer to a bitstream standard (instead of implementation)
> > whenever the stream is standards-conformant. This would allow players
> > that don't support proprietary codecs and don't want to deal with all
> > the fourcc mess of those to play files without a table of all the
> > implementation ids, and would allow players to play files encoded with
> > new implementations (of mpeg4, etc.) without upgrading their tables.
> >
> > (SHOULD instead of MUST would also be acceptable here, with the
> > implication that users may have to upgrade their players unnecessarily
> > to play files ignoring the recommendation.)
> >
> > > whats left:
> > >                                 I   AAA IAA a-avi
> > > supports old divx/xvid streams: X   X   X   X
> > > AVI->NUT->AVI wont change 4cc:  X   X   X   X
> > > MOV->NUT->MOV wont change 4cc:  X   X   X
> > > no table maintaince:                X       X
> > > decoder can use existing tables:    X   x   X
> > > decoder only needs single table:X   X   X   X
> > > encoder doesnt need to remap id:
> > >
> > >
> > > alternative suggestions, and comments welcome, personally iam fine with
> > > all the options left (for I and IAA a volunteer would be needed to maintain
> > > a few tables)
> >
> > I generally dislike anything involving nut-id. It's just like
> > matroska, useless bloat.
>
> well, as we still dont have volunteer for maintaining nut-id and no initial
> nut-id table either, I/IAA options are pretty dead anyway
> ivan do you volunteer to do the work? and can you make a table containing
> all 4cc of avi & mov with nice format & implementation names?

No problem. That's easy.
I hope you don't want it with past date. It needs few hours work.
Of course I'll do it only if the format_id is really going to be used.


I'd like discusion to be based on arguments and reasoning, not what
Dick likes and what not.