[mythtv] MPEG-4 trouble on SMP

Isaac Richards mythtv-dev@snowman.net
Thu, 31 Oct 2002 17:06:55 -0500

On Thursday 31 October 2002 12:34 am, Ray wrote:
> On Wed, Oct 30, 2002 at 10:35:50PM -0500, Samit Basu wrote:
> > Hi -
> >
> > I've got a strange problem with mythtv when I use MPEG-4 encoding.
> > Recordings work fine, as do playbacks, but when I watch live TV, the
> > video is corrupted.  It looks mostly fine, but there are blocking
> > artifacts -- blocks of color, white and black that fade in and out
> > periodically.  I don't have the same problem with rtjpeg, and the problem
> > doesn't go away with reduced capture resolution (I tried down to 320 x
> > 200). I'm running on a dual 1GHz PIII, and the artifacts go away when I
> > run a non-SMP kernel. (hence the subject line)...  I looked at the
> > rwlocks in
> > RingBuffer.cpp, but wasn't familiar enough with the code to spot the
> > problem (e.g., why is a read-lock used in the Write method?).  Any ideas?
> I don't have an answer but I can confirm that I've had the same problem on
> my Dual Celeron system.

If you guys with dualies could update to current CVS, edit settings.pro and 
uncomment the EXTRA_LOCKING line, recompile, etc, etc, and let me know if 
that helps things at all, I'd appreciate it.