[FFmpeg-devel] [PATCH] Fix return value for incomplete H264 frame packets

Pásztor Szilárd don
Wed Aug 25 16:40:30 CEST 2010


Michael Niedermayer:
> This discussion is difficult because you invent things that plain dont
> exist and i have to guess constantly what you actually refer to

Ok if my expressions confuse you then read $subj...

> now please explain where the problem is with calling the decoder again if
> it did not output a frame?

As Reimar D?ffinger already wrote at the beginning of this thread:
> That doesn't work due to
> a) 0-sized packets in AVI
> b) MPEG4 non-coded VOPs
> both of which need to be counted for this purpose but do not output frames.
> Of course it is possible to add special-cases to applications to handle
> this, but a solution in libavcodec that can be shared seems preferable to
> me.

So, with h264 that may be ok, but once the generic wrapper layer hides the
actual decoder function, there's no way to know if, despite the decoder not
producing a picture, a frame duration should be waited or not.
As it has been stated here many times in this discussion.

You:
> me:
> > And that's exactly what I'm talking about, that's why repeat_pict can't be
> > used to indicate the first-field case, unless hacking a -1 value into it
> > which is ugly and would probably break many things.
>
> what you write makes absolutely no sense, setting repeat_pict there to -1
> is wrong because it then would contain an incorrect value that does not
> represent the actual duration.

I thought it's clear that I'm AGAINST doing such a -1 hack...
It was a reply to you wrongly suggesting repeat_pict which was offtopic in
this thread.
I respect your work on libavcodec but you are repeatedly missing the point in
this thread. Please stop me sending to read the spec and the code, the
problem is not there.

s.

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