[mythtv-users] drifting audio synch, saa 7134
cal at graggrag.com
Fri Nov 2 20:49:21 UTC 2007
Sean Goodpasture wrote:
> On 11/2/07, *Alan Calvert* <cal at graggrag.com <mailto:cal at graggrag.com>>
> Having put together a modest little SD system for the grandkids, largely
> from the spare parts pile, there's this one little problem. Audio
> drifts out of synch, -200ms over ten minutes or so. I might have
> imagined it,
> but I swear it drifted back toward centre over a further period.
> I've searched on a few things, but can't establish if this is a known
> weakness of v4l in general, or more likely the saa7134 in particular.
> I'd love to know why it's happening, so any suggestions are welcome.
> mythtv-users mailing list
> mythtv-users at mythtv.org <mailto:mythtv-users at mythtv.org>
> Not a v4l expert at all, but since this is a framegrabber, could it be
> that the CPU is overwhelmed with all the processing? Have you tried
> tweaking the parameters for capture (changing the encoding types, not
> encoding the audio, etc.). I know that on my card that uses the
> saa7134, I've had some issues with the audio when recording SD (mostly
> with it dropping completely) and then sometimes the close captioning
> gets jacked (which is really bad when the audio drops).
Thanks for the info. The cpu is an Athlon X2 4600+ (2.4G), so I think it
should be able to cope. Here, the audio is pretty much rock solid apart from
the gradual synch drift. I'll experiment a bit further with the tweakables,
but this "spare parts" system looks like it'll need a cash injection by way
of new capture cards. Sigh.
More information about the mythtv-users