[FFmpeg-devel] [PATCH] make mpeg4 parser set has_b_frames

[elupus]

> On Thu, 22 Nov 2007 02:41:29 +0100, Michael Niedermayer
> <michaelni at gmx.at> wrote:
> 
> >On Thu, Nov 22, 2007 at 02:09:11AM +0100, elupus wrote:
> [...]
> >
> >of course, compute_pkt_fields() is the fast "just fill in what we can with no
> >knowledge of the future" code
> >genpts is the "find the pts even if we have to read ahead the whole file" code
> >
> >
> [...]
> >> But I assume you won't be bothered to look so the above was probably a waste 
> >> of typing.
> >
> >if has_b_frames==0 there are no b frames, so dts==pts
> >you cant expect code to provide you with correct output if you feed
> >it with incorrect input
> >
> >[...]
> 
> Well, true, but as I see it has_b_frames == 0 is the default value,
> and and not all parsers can set a correct value for it, as in the case
> was with the mpeg4 parser.
> 
> if demuxer can't provide you with a pts, only dts. assuming in that
> case that pts==dts is rather bad (if no parse that is able to set
> has_b_frame correctly is available). If pts was left as nopts, player
> could use the still correct dts for playback. while in it's current
> way it risks using an incorrect pts for playback resulting in poor
> playback. the problem here being that player have no idea if dts or
> pts is the best choice to sync on since both gets set.
> 
> if genpts is set, then fine make the assumption that parser gets it
> right cause user have asked us ffmpeg to figure out pts at any cost,
> and then we have to assume parser will do a correct job.
> 
> I suppose this type of change might require a version bump since it
> changes ffmpeg's default from always filling pts, to only doing so if
> it's likely correct.
> 
> 
> anyway, i've resent the patch. let's hope this news client get's it
> right.
> 
> Joakim

This is a resend in thread now hopefully, and with a mime attachment. This
actually looks like a reasonable client. Let's hope it doesn't mess up to..
can't afford to make even more mistakes :(

/Joakim
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