[linux-dvb] Re: AW: Re: VDR and DVD with pause -> noise corrupt

[Andreas Schultz <aschultz@warp10.net>]

Ralph Metzler wrote:
> Klaus Schmidinger writes:
>  > Ralph Metzler wrote:
>  > > 
>  > > Klaus Schmidinger writes:
>  > >  > If the audio frames don't contain a PTS, it's no wonder they get out of sync
>  > >  > (even in normal replay video and audio gets out of sync after some time).
>  > > 
>  > > They should not any longer after my last firmware syncing patch
>  > > about 10 days ago. This patch no longer was a workaround for the
>  > > "jerking picture bug", which would just sync audio/video at the start
>  > > of playback, but a complete fix. Syncing is always on now.
>  > 
>  > I just replayed a DVD with the latest versions of both driver and VDR,
>  > but after a while video and audio ran out of sync (audio was about half
>  > a second early). I'm not talking about external AC3 replay, but "internal"
>  > replay of both audio and video via the DVB card (converted by the 'ac3dec'
>  > that comes with VDR).
>  > 
>  > Do others also experience this, or is it just me?
>  >
>  > >  > Is there a way to have ac3dec generate the necessary PTS for the audio frames?
>  > >  > The original Dolby Digital frames that ac3dec uses to generate the "normal"
>  > >  > audio frames must, I believe, contain a PTS, don't they?
>  > > 
>  > > Of course they contain the correct PTS but reinserting it would not
>  > > help because the decoder hardware does not support syncing for PCM sound.
> 
> 
> But you were talking about "normal replay" which I understood to mean
> normal MPEG2 video and MPEG audio. 
> As I already wrote above, there is no syncing if using PCM. So, I am not
> surprised that sync is lost.
> Or does your ac3dec convert to MPEG audio? If it does, does it insert
> the proper PTSs?

As far as i understand, it generates LPCM frames. I experimented with 
copying the PTS from the original AC3 frame, but that totaly messed up 
the output.


Andreas



-- 
Info:
To unsubscribe send a mail to listar@linuxtv.org with "unsubscribe linux-dvb" as subject.