[Ffmpeg-devel] [BUG] no video transcoding

[Michael Niedermayer]

Hi

On Mon, Apr 23, 2007 at 10:55:06AM -0000, Wolfram Gloger wrote:
> Hi,
> 
> > to comment a little more on this as it seem to be a popular bug ;)
> > 
> > On Sun, Apr 15, 2007 at 08:13:37AM -0000, Wolfram Gloger wrote:
> > [...]
> > > Ok that's probably true -- although I maintain the patch is correct,
> > 
> > no it is not, cur_dts was approximately correct before and completely
> > wrong after the patch
> 
> How so?  cur_dts was set to some more or less random packet's dts
> that was the last one parsed in av_find_stream_info().

and your proposed patch sets it to the first dts from av_find_stream_info()
that is equally random

audio time stamp ?, ?, ?, 5, ?, ?, 123456, 123457, ...
video time stamp ?, ?, ?, ?, ?, ?, 123456, 123457, ...
timestamp discontinuity           ^

the first dts here would be 5 and 123456
filling things in would lead to something like:

audio time stamp      5,      6,      7,      5,      6,      7, 123456, ...
video time stamp 123456, 123457, 123458, 123459, 123460, 123461, 123456, ...

that is not better than what you get with the last dts, actually its
worse


> Then the packet queue is flushed and the next packet read has a
> (sometimetimes significantly) smaller dts value.
> This leads to a hard error (dts < cur_dts) for valid DVB streams.
> It is just a matter of luck if you don't hit this situation.
> 
> After the patch, cur_dts becomes AV_NO_PTS_VALUE -- how can that
> be "completely wrong".  Please elaborate.

its not completly wrong on its own but in combination with all the other
code it is

[...]
> I suspect that reverting 8465 will hide the problem, but
> please give me until tonight when I will allocate some time

time is no problem, i can wait, i just want a clean solution ...

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope
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