[MPlayer-dev-eng] lavf demuxer and video pts

[Dan Oscarsson]

tor 2009-12-03 klockan 14:37 +0100 skrev Michael Niedermayer:
> On Thu, Nov 26, 2009 at 07:28:21PM +0100, Dan Oscarsson wrote:
> > >>From what I can find out, an .avi file do not contain pts values so they
> > are generated by the demuxer.
> > 
> > So in a .avi file I would expect video and audio stream to start at pts
> > value zero.
> > 
> > Using normal mplayer demuxer audio pts starts at 0, and video pts for
> > first frame is 0.
> > 
> > Using demuxer lavf, audio pts starts at 0, and video pts for first frame
> > is 1/fps.
> > 
> > Why is lavf marking first frame with pts of what I would expect second
> > frame would have? Is the lavf demuxer skipping the first frame or is it
> > a bug?
> > 
> > It doesn't look right to me.
> 
> If you think theres a bug in lavf (and assuming of course you do understand
> frame reordering, and the differences betweem dts and pts) then please
> submit a bugreport to ffmpegs bugtracker (with sample file and all that is
> needed to reproduce)

All you need to do is to play, probably any normal xvid video (.avi
format), in mplayer and see the video pts values it prints on its status
line (though you may need to get mplayer display each status line on
separate lines to see it).

If the first video frame in a .avi files should be 0, and mplayer prints
the final pts values after any frame reordering, it looks like a bug to
me.

   Dan