Comment 17 for bug 229949

I really don't believe the problem is CPU resources. Using top on my box, I see the CPU stay around 60-70% usage at all times -- it never spikes above that, even in the guide during the pauses. This was the case even in 0.20 for me -- 0.21 seems no more resource hungry than 0.21.

I believe there is a regression between MythTV 0.20 and 0.21 wherein the guide and the video player (more specifically the deinterlacer) are competing for CPU time, and the deinterlacer is winning big time. Or something, I haven't looked that far yet.

In any case, I've attached a patch to the latest mythtv sources that addresses this issue. It doesn't correct the problem -- merely works around it. Basically it disables all deinterlace filters when entering the guide, and re-enables it when leaving. For me, it makes the guide usable again with the bob deinterlacer with practically no loss in video quality (you might see artifacts in the preview window, but my experience seems to suggest that with it that small, most effects won't be noticeable). For reference, CPU usage for me with and without this patch stays around 60 to 70% -- the only difference is that without the patch, the guide is very slow to respond.

Can you all rebuild your libmythtv.so files from source using the patch and tell me if it works for you? Here's quick instructions for rebuilding your libraries (as root):

$ apt-get source mythfrontend
$ cd mythtv-0.21.0+fixes16838
$ patch -p0 < ../guide-deinterlace.patch
$ dpkg-buildpackage
...
$ dpkg -i ../libmyth-0.21-0_0.21.0+fixes16838-0ubuntu3_i386.deb

Restart mythbackend and mythfrontend and you should be good to go. I can provide pre-built .deb packages for those that need them (ia32 only, as I don't have a 64-bit machine to build for).