[mythtv-users] audio problems -- digital crackling

[tomspam]

I've got mythtv 0.12 running on a p4 1.7 ghz machine, 256 MB ram, redhat 9, ATI tv wonder ve, soundblaster live (emu10k1).  video out is handled by a dedicated widget that sits between the video card and monitor.

I'm experiencing "crackling" artifacts when I watch live or recorded programs.  This doesn't happen with mythmusic.  Obviously the analog passthrough setup of the capture card would be the first suspect, but this isn't analog crackling.  It sounds more than anything like when jitter errors are present from ripping a CD to MP3: brief holes in the sound where it seems to stutter.  With a number of them together, the effect is like crackling.

The crackling is not constant -- it seems to be dependent on the sound going through it.  During silent stretches it's not present.  And it is concentrated at the onset of sounds -- for instance, the beginning of words.  By the time the end of the word is spoken it has stopped, but then when the next word begins it starts again.

So my guess would be that the mp3 encoding process is having a hard time keeping up -- but this machine seems like it ought to have enough power to keep up with a single stream of video.  It's not doing anything else other than apache (for mythweb), samba and sshd running in the background -- the problem occurs whether or not anyone is using those services, though, so I doubt a bottleneck getting to the HD is the problem.

This didn't seem to be an issue when I was running 0.11 from the apt-get mythtv install.  Since then I installed 0.12, and in the process installed mythmusic and its prerequisites.  Could a newer version of lame be the problem?  Does anyone have any other suggestions?

Thanks in advance.
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