[mythtvnz] LiveTV intermittently works for only 6 minutes then stops.

[Steve Nicholson]

With the All Blacks playing this weekend I've been pushed to get MythTV 
working so we can watch the game on Prime (We don't have a TV).

Problem:
Start MythTV front end, select watch TV, choose Prime (doesn't matter 
which channel I tried) after about 5-7minutes screen goes blank, sound 
stops. If I try to change channel at this point (e.g. to TV1), a still 
image of what was last on current channel (e.g. Prime) comes up with the 
OSD "channel info" displayed along the bottom of screen, doesn't change 
channel and no video/sound on current channel. I have to use keyboard 
"esc" key to go back to main menu and click on "Watch TV" again. Note 
I've check screen saver is off:-)

Doesn't appear to matter which channel I choose although, oddly as soon 
as the "Infomercials" came on TV1 at 8:30am (after crashing 3 times from 
8am) it was fine for over an hour. I've never sat through and hour of 
infomercials before and now can't wait for my new robot vacuum cleaner, 
hair condition and ab roller to turn up!:-(. Changing away to TV2, 
liveTV crashed again but then worked fine on C4 for 50 minutes before I 
changed to Prime which then crashed.

Signal 45% with SNR 4.8d/b, local transmitter is only 3km away direct 
line of site with roof antenna.

Only thing I can see in backend logs that means anything is "Changing 
from WatchingLiveTV to None" but I can't see why it changed. e.g.
Jun  5 08:06:22 myth mythbackend: mythbackend[16876]: N Expire 
autoexpire.cpp:641 (SendDeleteMessages) Expiring 0 MB for 1003 at 
2014-06-04T20:01:11Z => "3 News: Firstline"
Jun  5 08:06:22 myth mythbackend: mythbackend[16876]: I TVRecEvent 
tv_rec.cpp:1050 (HandleStateChange) TVRec[1]: Changing from 
WatchingLiveTV to None
Jun  5 08:06:22 myth mythbackend: mythbackend[16876]: I TVRecEvent 
tv_rec.cpp:834 (FinishedRecording) TVRec[1]: 
FinishedRecording(1003_2014-06-04T20:01:13Z) damaged 
recq:<RecordingQuality overall_score="0" key="1003_2014-06-04T20:01:13Z" 
countinuity_error_count="0" packet_count="2210734">#012    <Gap 
start="2014-06-04T18:30:00Z" end="2014-06-04T20:01:13Z" duration="5473" 
/>#012    <Gap start="2014-06-04T20:06:17Z end="2014-06-04T20:30:00Z" 
duration="1422" />#012</RecordingQuality>

Setup:
MythBuntu 12.04.4
MythTV 2.7 with fixes (Frontend and backend on same computer).
Motherboard: Asus P5WDG2 WS Pro,  Intel E7200 2.53GHZ, 3GB RAM.
Video: Galaxy NVIDIA GeForce GT 430 (43GGS8HX3SPZ) 1 GB DDR3 SDRAM PCI 
Express x16.
Tuner: WinTV-HVR-1100 Hauppauge PCI DVB-T Digital TV Tuner Card.

I also have Zoneminder working on this computer with two analogue 
cameras. "top" with LiveTV working CPU usage doesn't go over 30% with or 
without Zoneminder running, with just Zoneminder CPU is about 10% or 
less. I don't think Zoneminder is the problem, I've just watched an hour 
of Prime this evening without an issue and I've started and stopped 
Zoneminder over this time.

OK, looks like it is an intermittent problem since LiveTV has worked 
perfectly this evening for the last 90 minutes on Prime. At least Top 
Gear was worth spending the time on.

What I should be looking at to figure out why LiveTV ramdomly stops working?

Thanks
Steve