[mythtv] Prebuffer wait time out with LiveTV on svn 7936

[Bob Cottingham]

I upgraded to svn 7936 and found that I quickly get the following with LiveTV:

2005-11-19 19:08:42.999 TV: Changing from None to WatchingLiveTV
2005-11-19 19:08:43.003 Realtime priority would require SUID as root.
2005-11-19 19:08:43.337 Video timing method: SGI OpenGL
2005-11-19 19:09:03.458 NVP: prebuffering pause
2005-11-19 19:09:04.106 New DB connection, total: 3
2005-11-19 19:09:04.108 New DB connection, total: 4
2005-11-19 19:09:05.093 Prebuffer wait timed out 10 times.
2005-11-19 19:09:05.844 NVP: prebuffering pause
2005-11-19 19:09:09.568 NVP: prebuffering pause
2005-11-19 19:09:21.193 NVP: prebuffering pause
2005-11-19 19:09:23.128 NVP: prebuffering pause
2005-11-19 19:09:24.763 Prebuffer wait timed out 10 times.
2005-11-19 19:09:26.245
RingBuf(/var/mythtv/tv/1003_20051119190848.mpg): Waited 4 seconds for
data to become available, waiting again...
2005-11-19 19:09:26.415 Prebuffer wait timed out 10 times.
2005-11-19 19:09:28.066 Prebuffer wait timed out 10 times.
2005-11-19 19:09:29.718 Prebuffer wait timed out 10 times.
2005-11-19 19:09:30.247
RingBuf(/var/mythtv/tv/1003_20051119190848.mpg): Waited 4 seconds for
data to become available, waiting again...
2005-11-19 19:09:31.369 Prebuffer wait timed out 10 times.
2005-11-19 19:09:33.021 Prebuffer wait timed out 10 times.
2005-11-19 19:09:34.249
RingBuf(/var/mythtv/tv/1003_20051119190848.mpg): Waited 4 seconds for
data to become available, waiting again...
2005-11-19 19:09:34.672 Prebuffer wait timed out 10 times.
2005-11-19 19:09:36.324 Prebuffer wait timed out 10 times.
2005-11-19 19:09:37.976 Prebuffer wait timed out 10 times.
2005-11-19 19:09:38.250
RingBuf(/var/mythtv/tv/1003_20051119190848.mpg): Waited 4 seconds for
data to become available, waiting again...
2005-11-19 19:09:39.628 Prebuffer wait timed out 10 times.
2005-11-19 19:09:41.279 Prebuffer wait timed out 10 times.
2005-11-19 19:09:42.251
RingBuf(/var/mythtv/tv/1003_20051119190848.mpg): Waited 4 seconds for
data to become available, waiting again...
2005-11-19 19:09:42.931 Prebuffer wait timed out 10 times.
2005-11-19 19:09:44.583 Prebuffer wait timed out 10 times.
2005-11-19 19:09:46.235 Prebuffer wait timed out 10 times.
2005-11-19 19:09:46.253
RingBuf(/var/mythtv/tv/1003_20051119190848.mpg): Waited 4 seconds for
data to become available, waiting again...
2005-11-19 19:09:47.886 Prebuffer wait timed out 10 times.
2005-11-19 19:09:49.537 Prebuffer wait timed out 10 times.
2005-11-19 19:09:50.254
RingBuf(/var/mythtv/tv/1003_20051119190848.mpg): Waited 4 seconds for
data to become available, waiting again...
2005-11-19 19:09:51.190 Prebuffer wait timed out 10 times.
2005-11-19 19:09:52.841 Prebuffer wait timed out 10 times.
2005-11-19 19:09:54.255
RingBuf(/var/mythtv/tv/1003_20051119190848.mpg): Waited 4 seconds for
data to become available, waiting again...
2005-11-19 19:09:54.256
RingBuf(/var/mythtv/tv/1003_20051119190848.mpg): Waited 14 seconds for
data to become available, aborting

This happens with both my local and remote frontends (both at 7936). 
LiveTV works for a couple minutes, then freezes on the frontend with
the above error.  I believe that each time it froze it was during a
channel change.  If I restart the frontend or use a second frontend I
find that the LiveTV file is fine and continued recording for several
minutes.  I can play the file without any problem.  I occasionally saw
prebuffering waits with LiveTV prior to the LiveTV change, but it
wasn't like this and didn't freeze up. I'm using ivtv-0.4.0.

When I try to run the frontend under gdb, I get the following:

Starting program: /usr/local/bin/mythfrontend
[Thread debugging using libthread_db enabled]
[New Thread -1247824160 (LWP 12870)]
Qt: gdb: -nograb added to command-line options.
         Use the -dograb option to enforce grabbing.
2005-11-19 19:33:24.805 Using runtime prefix = /usr/local
2005-11-19 19:33:24.941 XScreenSaver support enabled
2005-11-19 19:33:25.101 New DB connection, total: 1
2005-11-19 19:33:25.114 Total desktop dim: 800x600, with 1 screen[s].
2005-11-19 19:33:25.117 Using screen 0, 800x600 at 0,0
2005-11-19 19:33:25.119 Enabling Settings Cache.
2005-11-19 19:33:25.119 Clearing Settings Cache.
[New Thread -1250350160 (LWP 12878)]

Program received signal SIG33, Real-time event 33.
[Switching to Thread -1250350160 (LWP 12878)]
0xb63aebc8 in clone () from /lib/tls/i686/cmov/libc.so.6
(gdb)
[2]+  Stopped                 gdb mythfrontend

Both my frontends are running on Kubuntu 5.10. Running mythfrontend
normally works.  I'd be happy to provide a backtrace if someone could
help me get it working.

Thanks for any help anyone could provide.

Thanks,
Bob C