Subsonic degrades video quality on MythTV system

[hanker]

Greetings

I have been running Subsonic for a little over two years on a plug computer (Sheevaplug, 1.2 GHz ARM processor, 512 MB RAM). It worked fine, but a little slow - no big deal.

Last weekend I thought I'd install it on a beefier system: a desktop PC with 3.1 GHz dual-core Athlon, 4 GB RAM, xubuntu 12.04, NVidia GT 430 video card with VDPAU hardware video acceleration. The system is used primarily as a MythTV (mythtv.org) system for TV recording and playback. It drives a 47-inch LG LED TV by HDMI. It has been working well for about 1.5 years. The video quality on MythTV HD playback is just about perfect.

Then I installed Subsonic last weekend. I have successfully streamed audio and video over the LAN with Subsonic. But the video quality during MythTV playback on the TV that's hooked directly to the PC by HDMI was very noticeably degraded by the Subsonic installation: I started getting "frame-tearing":

http://www.mythtv.org/wiki/Frame_display_timing

This had never happened before. I stopped the Subsonic service and I still got tearing. Then I logged out and back in (I guess this restarts the X window system). This took care of it: no more tearing - the MythTV video on the attached TV was back to its previous excellent state.

So Subsonic is somehow interfering with and degrading MythTV video playback on the attached TV.

This process is 100% repeatable: launch Subsonic and the MythTV video output is very noticeably degraded. Stop Subsonic, log out and back in, and MythTV video output on the attached TV is perfect again.

I hate to have to uninstall Subsonic from this machine because I really like the software but MythTV is ultimately more important on this system.

Any ideas what's happening here? Any chance that this might be fixed?

Thank you!

-FBP