[FFmpeg-devel] How to get PCR (Programe Clock Reference)value from TS file ?

Michael Niedermayer michaelni
Sun Nov 4 12:32:45 CET 2007


On Wed, Aug 08, 2007 at 02:29:57PM +0200, Thomas Parmegiani wrote:
> > -----Message d'origine-----
> > De : ffmpeg-devel-bounces at mplayerhq.hu
> > [mailto:ffmpeg-devel-bounces at mplayerhq.hu]De la part de Michael
> > Niedermayer
> > Envoye : mercredi 8 aout 2007 14:11
> > A : FFmpeg development discussions and patches
> > Objet : Re: [FFmpeg-devel] How to get PCR (Programe Clock
> > Reference)value from TS file ?
> >
> >
> > Hi
> >
> > On Wed, Aug 08, 2007 at 12:33:28PM +0200, Thomas Parmegiani wrote:
> > > Hi all !
> > >
> > > Can anyone tell me how to retrieve PCR value from TS file ?
> > > I noticed this value seems to be filled in "cur_pcr" variable from
> > > MpegTSContext structure but this structure is not declared in
> > .h file. Is
> > > there any other about how I can get this value or should I need to move
> > > strcut to mpegts.h ?
> > > What is the unit of the variable cur_pcr ? I tested with a TS @
> > 25fps and
> > > after each call of av_read_frame the different values of cur_pcr are
> > > alternatively 14,19,14,19,...
> > > One last question : I would like this value has to be read from
> > TS file and
> > > not calculated from ffmpeg is it that ffmpeg does ?
> > >
> > > Can anyone help me ?
> >
> > why do want to know the PCR value?
> 
> On my application I need to demux a MPEG2 transport stream received from
> satellite then send audio decoded frames and video MPEG2 frames to a
> hardware device wich will display the A/V frames. This hardware device needs
> the PCR value to accelerate or slow down the frame display process in order
> to prevent from buffer overflow or empty buffer. All I need to do is to give
> the PCR information value (Which should be a part of computation field
> (correct me if I am wrong)) to my hardware device.

well add a pcr field to AVPacket set it in mpeg.c and send us a patch

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

No human being will ever know the Truth, for even if they happen to say it
by chance, they would not even known they had done so. -- Xenophanes
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