Hi All,

I've been successfully running KnoppMyth for a few years now on this same box, upgraded to R5F27 when it first came out, things have been going fine. My setup is modest: older 1gig AMD, 512MB RAM, PVR-350, 20gig hard drive for the OS and 200gig hard drive for recordings.

I have a strange problem that has popped up with a hard drive replacement. Last week, my box suddenly crashed hard. When I went to start it back up, my recordings hard drive was clicking and the machine wouldn't boot.

Long story short, I installed a new 320gb hard drive, was able to breath enough life into the old one to copy all my recordings over to the new one. Adjusted bios, fstab, told MythTV to look to the new directory for its recordings and voila... almost.

Since then, I've been having jittery video on SOME channels. It kind of seems like it's every other channel, but I haven't scrolled through them all to test that. I'm not having any problems with the recordings that came before the switch and there's no problems with MythFrontend or the OSD, it's just the video.

It's not my cable - I've plugged directly into the TV and there's no issue with it.

Any ideas? I've ensured that DMA is active on the new drive (it is). I haven't changed any other settings - I can't imagine why I'd have to.

Or, is all this hard drive business a red herring and did whatever caused my machine to freeze up also hurt my PVR-350?

Thanks in advance.

Possibly. Have you tried playing back the recordings somewhere else?

The key to troubleshooting any problem like this is isolation. Is it the recording itself, or the playback? If it's the recording, have any of the capture settings or input connections changed? If it's the playback, have you fiddled with any of the output settings? Have you checked the logfiles for errors? Have you checked for any loose connections or cards inside the box? Have you checked for any debris from the the HD swap on the motherboard? The more things you can eliminate the more likely you are to be able to fix it.

I just tried playing back one of them using mplayer and the jitters were definitely there on the recording itself. I wouldn't expect it to be the playback, since the recordings from prior to the hard drive replacement all play fine.

The only thing that I changed in mythtv-setup was the directory to store recordings in, since the old HD was mounted to /video and I mounted the new one to /video2.

Dmesg provides the following error, repeating it a lot:

ivtv0: All encoder MPG stream buffers are full. Dropping data.
ivtv0: Cause: the application is not reading fast enough.
ivtv0: All encoder VBI stream buffers are full. Dropping data.
ivtv0: Cause: the application is not reading fast enough.

Does this mean that, for some reason, video isn't being transferred to my new hard drive fast enough to maintain the ivtv stream?

I did try adding to my ivtv config (from your RF27 Hints thread), but that didn't help.

Those errors are almost certainly related to your jittery recordings. See the Performance Optimization page on the wiki for some other things to try.

http://www.knoppmythwiki.org/index.php?page=PerformanceOptimizeHowTo

Sorry, I didn't have any further time to look into this until just now.

I put back in the enc_mpg_buffer line and I'm no longer seeing any of those errors in my logs, but my picture is still jittery and I'm getting the following in my MythFrontend log:



I tried turning off using the PVR-350 decoder for playback and then switched to Live TV. It was totally slow, but the jitters were still there, so it's definitely something on the way in.

Any ideas beyond increasing the buffer? I've searched for the IVD error in the forums, but neither of the threads that came up were helpful to me. (Again, not sure it's related, but it's the only thing that jumped out at me.)

I'm considering doing a backup and reinstall, since things were working just fine before the hard drive swap. Any guesses as to whether or not that will help?

Have you dealt with the Known Issue related to nonstandard capture resolutions in the R5F27 Hints? Sorry to be so terse but I'm working on a set of fixes for the backup and restore code at the moment...

No worries about being terse, I really do appreciate the help because I'm totally stumped here.

To answer the question: yes, I changed all my recording profiles to 720x480, instead of 480x480, and I disabled VBI in mythtv-setup.

Just another update, though no solution. I checked the connections again on the PVR-350, the hard drive, and the RAM. I did an auto-upgrade reinstall, but I'm still seeing the jittery video.

Should I try a total fresh install instead of an auto-upgrade? I don't really want to lose my recording details/history, etc., but if I backup and restore mythconverg, won't that just take any potential bad settings along for the ride?