[pvrusb2] Audio video syncro using kaffeine.

[Mike Isely]

On Mon, 22 May 2006, xavier.gnata at free.fr wrote:

> Hi,
>
> Having a mostly perfect driver is great but having a compatible TV application
> of this century is also great ;)
>
> xawtv4 is almost dead.
>
> As mentioned on this list, kaffeine fifo:/dev/video0#demux:mpeg does the job.
> I'm fine with it because kaffeine devel is very active (it is fully part of kde
> :))
>
> The only problem is that audio is not sync to video using kaffeine (sound is
> always a bit late).
>
> I have no clue if it's kaffeine related or if it can be simply solved seting a
> kaffeine option.
>

Combining of the video and audio streams happens inside the Conexant 
encoder chip in the device itself.  The driver doesn't do a thing to help 
or hinder that operation since it's just part of what the hardware encoder 
does.  If sync issues are happening then it's either in the hardware 
(seems unlikely) or the application is not keeping things synced on 
playback after it separates the streams.

Can you do other things in Kaffeine to cause sync problems?  Can you 
record an mpeg2 file from the device (i.e. 'cat /dev/video0 
>/tmp/foo.mpg') and play that back through Kaffeine and get different 
behavior?  If you can see still sync issues even when playing back a 
recorded file, try playing back that same file through mplayer and see if 
the same thing happens.  Answers to those experiments might help isolate 
the point in the pipeline where sync is being lost.

   -Mike

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