[Mplayer-cvslog] CVS: main/DOCS/tech mpcf.txt,1.54,1.55

[Michael Niedermayer]

Hi

On Saturday 01 May 2004 07:34, D Richard Felker III wrote:
> On Sat, May 01, 2004 at 12:54:01AM +0200, Michael Niedermayer CVS wrote:
> > CVS change done by Michael Niedermayer CVS
> >
> > Update of /cvsroot/mplayer/main/DOCS/tech
> > In directory mail:/var2/tmp/cvs-serv2525
> >
> > Modified Files:
> > 	mpcf.txt
> > Log Message:
> > additional start_code rule (implemenattion does this since a long time
> > already)
> >
> >
> > Index: mpcf.txt
> > ===================================================================
> > RCS file: /cvsroot/mplayer/main/DOCS/tech/mpcf.txt,v
> > retrieving revision 1.54
> > retrieving revision 1.55
> > diff -u -r1.54 -r1.55
> > --- mpcf.txt	28 Apr 2004 03:19:35 -0000	1.54
> > +++ mpcf.txt	30 Apr 2004 22:53:59 -0000	1.55
> > @@ -234,6 +234,9 @@
> >  	0x11405BF2F9DBULL + (((uint64_t)('N'<<8) + 'S')<<48)
> >  frame_startcode
> >  	0xE4ADEECA4569ULL + (((uint64_t)('N'<<8) + 'K')<<48)
> > +	frame_startcodes MUST be placed immedeatly before a keyframe if the
> > +	previous frame of the same stream was a non-keyframe
> > +
>
> Very bad rule. What if you have an audio codec that alternates
> I/P/I/P/...?? This is a horrible waste. 
does such a audio codec exist?
IMO if a (audio) codec supports P frames then the majority (>90%) of frames 
should be of P type, as P types should be smaller 

> There's no reason for such a 
> rule...
it allows simpler seeking, for example our current implementation cant seek to 
type 0 frames, so IMHO it isnt unreasonable to expect other simple demuxers 
to be incapable of seeking to startcode-less frames

anyway, iam not against removing this after our implementation supports 
seeking to startcode-less frames and we see that doing so doesnt require 
overly complicated code
i just have bad feeling after implementing seeking to the old type 1 frames, 
as i first thought we could just follow the backward pointers when we need to 
search for the previous frame, sadly this fails fataly if the stream is 
damaged

[...]
-- 
Michael
level[i]= get_vlc(); i+=get_vlc();		(violates patent EP0266049)
median(mv[y-1][x], mv[y][x-1], mv[y+1][x+1]);	(violates patent #5,905,535)
buf[i]= qp - buf[i-1];				(violates patent #?)
for more examples, see http://mplayerhq.hu/~michael/patent.html
stop it, see http://petition.eurolinux.org & http://petition.ffii.org/eubsa/en