[mythtv-users] Missed Recordings on One DVB Tuner

[James Crow]

Hello list,

  I am having a problem with missed recordings on a single input on
one DVB adapter. I have a total of 12 inputs on several physical
devices. The first four inputs are on a HVR-2250 dual tuner (single
coax connection which eliminates cabling problems) PCI-E card.
Multi-rec is enabled and each physical tuner has two inputs in Myth. I
am using the beta driver from Steven Toth that includes analog support
and those inputs are 11 and 12. All inputs from each tuner are in
their own input group. I am running Mythbuntu 10.04 amd64 on both my
BE machines. I have seen no failed recordings on my SBE which has a
HD-PVR and another different DVB card. Myth version is:

james at james-desktop:/var/log/mythtv$ mythbackend --version
Please attach all output as a file in bug reports.
MythTV Version   : 5aa7665
MythTV Branch    : fixes/0.24
Network Protocol : 63
Library API      : 0.24.20101129-1
QT Version       : 4.6.2
Options compiled in:
 linux debug using_alsa using_jack using_oss using_pulse
using_pulseoutput using_backend using_bindings_perl
using_bindings_python using_directfb using_dvb using_firewire
using_frontend using_hdhomerun using_hdpvr using_iptv using_ivtv
using_joystick_menu using_lirc using_mheg using_opengl_video
using_opengl_vsync using_qtdbus using_qtwebkit using_v4l using_x11
using_xrandr using_xv using_bindings_perl using_bindings_python
using_mythtranscode using_opengl using_vdpau using_ffmpeg_threads
using_live using_mheg

Since the last system restart I have had several failed recordings on
input 3 (first multi-rec input on second physical tuner on HVR-2250).
All recordings from inputs 1 and 2 are fine. I rarely need input 4,
but I have seen a few recordings with no problems from that input. I
also have some recordings from input 3 that worked.

I really only have two channels (on different multi-plexes) that fail.
The two channels also happen to be the newest recording rules. Prior
to the failed recordings I think only inputs 1 and 2 were being used.
When I added more recording rules I think Myth began using input 3 and
recordings started to fail.

Right now I am running with standard logging but will be increasing it
when I can restart the MBE. I have lots of these errors in my logs:
2011-01-04 10:22:56.811 ProgramInfo(1071_20101223135900.mpg), Error:
GetPlaybackURL: '1071_20101223135900.mpg' should be local, but it can
not be found.
2011-01-04 10:22:56.817 ProgramInfo(1071_20101222135900.mpg), Error:
GetPlaybackURL: '1071_20101222135900.mpg' should be local, but it can
not be found.
2011-01-04 10:22:56.894 ProgramInfo(1071_20101228135900.mpg), Error:
GetPlaybackURL: '1071_20101228135900.mpg' should be local, but it can
not be found.
2011-01-04 10:22:57.023 ProgramInfo(1071_20101224135900.mpg), Error:
GetPlaybackURL: '1071_20101224135900.mpg' should be local, but it can
not be found.
2011-01-04 10:22:57.029 ProgramInfo(1071_20101221135900.mpg), Error:
GetPlaybackURL: '1071_20101221135900.mpg' should be local, but it can
not be found.
This particular block is errors from one channel and show that often
fails. It recorded on 2011-01-03, but failed for the other 7 episodes
that should be recorded.

Filtering out errors related to missing files from the failed
recording gives me these errors:
2011-01-03 21:04:14.721 DevRdB(/dev/dvb/adapter0/frontend0) Error:
Driver buffers overflowed
2011-01-03 21:04:14.721 DevRdB(/dev/dvb/adapter1/frontend0) Error:
Driver buffers overflowed
2011-01-03 21:29:27.557 DevRdB(/dev/dvb/adapter1/frontend0) Error:
Driver buffers overflowed
2011-01-03 21:29:27.557 DevRdB(/dev/dvb/adapter0/frontend0) Error:
Driver buffers overflowed
2011-01-03 21:29:29.060 DevRdB(/dev/dvb/adapter0/frontend0) Error:
Driver buffers overflowed
2011-01-03 21:32:31.218 MainServer, Error: PREVIEW_SUCCESS but no receivers.
2011-01-03 21:51:33.125 DevRdB(/dev/dvb/adapter0/frontend0) Error:
Driver buffers overflowed
2011-01-03 21:51:33.125 DevRdB(/dev/dvb/adapter1/frontend0) Error:
Driver buffers overflowed
2011-01-03 21:52:26.587 [ac3 @ 0x7fdd594335a0]frame sync error
2011-01-03 21:52:26.596 AFD Error: Unknown audio decoding error
2011-01-03 22:02:31.581 MainServer, Error: PREVIEW_SUCCESS but no receivers.
2011-01-03 22:02:31.897 MainServer, Error: PREVIEW_SUCCESS but no receivers.

I also noticed a few MythSocket errors like this:
2010-12-28 23:00:11.232 MythSocket(e12be0:-1): writeStringList: Error,
socket went unconnected.
			We wrote 0 of 662 bytes with 1 errors

Any ideas are greatly appreciated.

I think any sort of signal issue can be ruled out because the card has
a single coax connection and then splits the signal internally. Also
recordings on the same mplex and even same channel work at other times
from the input that fails.

Thanks,
James