[Ffmpeg-devel] h264 decoder/ts-streams

Julian Scheel julian
Mon Nov 6 13:47:54 CET 2006


Am Samstag, 4. November 2006 19:05 schrieb Derk-Jan Hartman:
> On 3-nov-2006, at 18:04, Julian Scheel wrote:
> > Hi
> >
> > Am Freitag, 3. November 2006 17:57 schrieb Nico Sabbi:
> >> no, demuxers doesn't have to do this.
> >> Use the stream_type in the pmt to determine the type of the video
> >> stream
> >> and let the decoder to the rest (it will search the right syncword)
> >
> > I thought this is what xine does normally and what does not work
> > with xines
> > current implementation.
> >
> >> as above, this is decoders' job; besides, in h264 0x000003 sequences
> >> have to unescaped
> >
> > hmm, ok. But why does VLC do that?
>
> Because early on, the decoder/parser in libavcodec did NOT do that,
> but crash instead.
> As a matter of fact, in case the first nal is not a SPS/PPS pair, it
> still tends to crash regularly atm. (no i don't have samples. this is
> just by experience watching live TS streams).
>
> Also, in VLC not everything by definition goes to a decoder.
> Sometimes the data is just repacked for one or more other
> destinations. Therefore all h264 data will be packed internally to
> the startcode prefixed version, and be later reprocessed to fit best
> it's final destination streams.

Hmm, ok. But then I don't undeestand, why xine can't play the sample file I 
provided? - Could you possibly test that?


-Julian




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