[mythtv] DVB recording issues

[Jason W]

On 2005/03/20 09:15, Hamish Moffatt wrote:
> I'm running 3 cards also. Anything interesting in your kernel log?
> (dmesg). If you have bt878 cards, some of your glitches may be
> non-signal related.

All 3 of my cards are VisionPlus DVB cards and are indeed BT878 based. 
nForce2 chipset with PATA disks. I am running 2.6.10 at the moment, 
system froze when booting on 2.6.11 when loading DVB drivers (forget 
which module). I intend on trying 2.6.11.5 when I get the chance.

I had another audio loss today on a recording while only 1 card was 
active. The 2nd audio stream was fine. It was almost certainly trigged 
by bad signal as the picture has noticeable artifacting around 11:54:55 
where the drop out occurred.

/var/log/syslog:
Mar 23 11:53:01 sentry kernel: Unknown EII protocol 86DD: csum at 16
Mar 23 11:53:32 sentry last message repeated 73 times
Mar 23 11:54:00 sentry last message repeated 69 times
Mar 23 11:54:01 sentry kernel: Unknown EII protocol 86DD: csum at 16
Mar 23 11:54:32 sentry last message repeated 72 times
Mar 23 11:55:01 sentry last message repeated 71 times

Not sure what this is about but it seems to be happening often.

/var/log/mythbackend.log
2005-03-23 11:54:11.641 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 512
2005-03-23 11:54:22.544 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 660
2005-03-23 11:54:22.866 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 512
2005-03-23 11:54:27.104 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 512
2005-03-23 11:54:27.470 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 512
2005-03-23 11:54:28.692 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 512
2005-03-23 11:54:36.811 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 512
2005-03-23 11:54:42.447 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 512
2005-03-23 11:54:44.383 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 512
2005-03-23 11:54:44.499 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 512
2005-03-23 11:54:49.354 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 512
2005-03-23 11:54:56.687 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 660
2005-03-23 11:54:57.153 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 650
2005-03-23 11:55:01.616 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 512
2005-03-23 11:55:06.900 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 660
2005-03-23 11:55:09.505 DVB#1 WARNING - Transport Stream Continuity 
Error. PID = 512

Seems I get a lot of continuity errors. This is from ABC Brisbane. 512 
is video, 660 is AC3 and and 650 is MP2 if at all useful.

The signal from the antenna cannot be too bad as a Teac DV-B300 STB runs 
perfect on it. I have an amplifier on the line at the moment which I 
need for SBS. Attenuating the VHF frequencies or removing the amp all 
together do not affect anything besides my ability to receive SBS at 
all. (i.e. same number of signal errors).

Right now I am doing a test by recording 3 different channels at once. 
Initially, watching the recordings as they are in progress on a remote 
frontend, it seems fine without any visible errors. Within a few minutes 
I am having buffering problems. Load average is up to 18 and peaked at 
23 before I canceled the recordings. my myth log shows a lot of

2005-03-24 00:28:02.644 IOBOUND - blocking in ThreadedFileWriter::Write()

as well as the continuity errors from above occurring on all cards. 
Nothing different in syslog (i.e. still Unknown EII protocol messages).

This seems to be wrecking havoc on my recordings. Does anyone have any 
thoughts on this? The load average skyrocketing is disturbing. When not 
recording my load average is almost always under 1.

It certainly looks like the audio problem is to to with corrupted 
transport streams.

Any hints/tips people can provide would be most appreciated.

Thank you and regards,

Jason