[mythtv-users] jerky video and sound problems with live tv and recorded tv internal player only.

Braindead Braindead at diablops.com
Wed Mar 2 15:29:16 UTC 2011

I've spent several days trying to get to the root of this.  I recently upgraded from 0.21 to 0.23, replaced my PVR150 with a HD-5500 (dropped cable and going OTA).  I also upgraded the old nvidia 5500 with a 512MB 8500 GT.  Currently using svideo out as my TV is kinda old and the one HDMI input is being used.

System is an AMD X2 3800+
All HD's are 7200rpm SATA and plenty of free space.
2gig RAM.
using mobo audio-nVidia Corporation CK804 AC'97 Audio Controller (rev a2)
Gentoo distro

This system is capable of playing HD video files via mplayer with AC3 optical output..etc..  Never had any problems with high bitrate stuff.

However the internal player has serious trouble playing recorded shows or live tv.  I can take the recorded mpg file and play on the same machine with mplayer and it's completely fine, no errors reported by mplayer and a one hour show test was fine from start to finish.

Playing with the internal player stuttery, audio out of sync.  Live TV generally starts stuttery, cleans up shortly (as the buffers fill my guess) and then over time (say a minute or two) the audio starts to cut out getting progressively worse.  The weird thing is that sometimes only some of the audio disappears, we will be watching the news and hear the background music (intro stuff that they talk over) but the vocals are either gone or extremely low volume.  Once that happens things don't seem to get better.  

I have tested the card with azap and a 10 minute recording via "cp /dev/dvb/adapter0/dvr0 test.mpg" which resulted in a perfect recording. I've also watched live TV via vlc with no trouble at all, although as of yet I have not watched it via vlc for an extended period of time only 2-3 minutes.

As this was an upgrade from 0.21, I'm wondering if I've got 'cruft' in the recording or playback profiles that may be causing this?  I looked over the profiles and they 'seem' okay, I set the playback profile to CPU+ (from Normal I believe) and that seemed to have no affect.  

Now that I've upgraded to a video card that supports VDPAU, I'll likely upgrade to that.. however considering that everything except the internal player plays live and recorded streams from the HD-5500 just fine.. I doubt that'll help.

I'm thinking my next step is to dump all the recording and playback profiles, and pump in the defaults for 0.23.

Any other suggestions?


Actresses will happen in the best regulated families.
		-- Addison Mizner and Oliver Herford, "The Entirely
		New Cynic's Calendar", 1905

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