[Mplayer-cvslog] CVS: main/libmpdemux demux_lavf.c,1.8,1.9

[Michael Niedermayer]

Hi

On Monday 25 October 2004 04:18, D Richard Felker III wrote:
> On Sun, Oct 24, 2004 at 09:17:57PM +0200, Michael Niedermayer CVS wrote:
> > CVS change done by Michael Niedermayer CVS
> >
> > Update of /cvsroot/mplayer/main/libmpdemux
> > In directory mail:/var2/tmp/cvs-serv16177
> >
> > Modified Files:
> >  demux_lavf.c
> > Log Message:
> > 10l (mplayer doesnt like AV_NOPTS_VALUE)
>
> i'm curious if there's a good reason it exists at all.
> in principle it's possible to figure out the pts for any frame in any
> file, otherwise it would be impossible to play it correctly. is this

lots of things are possible in principle, for example finding the mpeg4 stream 
with the highest PSNR for exactly <= x bits, just try all such streams ...


> for strange formats where the codec is needed to find the pts??

mpeg-ps is one if these strange formats, pts and dts only need to be coded 
once every 0.7 secs, and together with the repeat_first_field flag its a 
little tricky to find the pts/dts, lavf currently can calculate the exact dts 
for mpeg-ps but not the pts, this would require demuxing and parsing of the 
mpegvideo headers ahead until the next non-b frame, and for a common format 
like mpeg the slowdown simply isnt acceptable

[...]
-- 
Michael

"I do not agree with what you have to say, but I'll defend to the death your
right to say it." -- Voltaire