[mythtv-users] DVB-C: Problems with just couple of multiplexes

[Kari Salmela]

Hi

I am experiencing some severe picture quality problems (errors at rate
sometimes >10/second) with certain channels with svn 10856 (and earlier
also)
Most of the channels work ok though. It would be easy to think it's a
signal quality problem, but when I czap to one of the problematic
channels, BER is 0 all the time and signal is at same level than the
channels which work ok. These are encrypted channels, so I moved CAM to
another card just to exclude bad card. CPU load is ~20% when watching
live tv and ~1% when only recording, so it should not be a performance
problem either. (how one could tell whether system really is performing
too slow??) Sometimes cpu load is >1, but other channels work just fine.

The picture has dropouts, sound has clicks and bleeps and I get errors
in console look like this:
[mpeg2video @ 0xb74247e4]*ac*-*tex* damaged at 0 14
[mpeg2video @ 0xb74247e4]skipped MB in I frame at 2 20
[mpeg2video @ 0xb74247e4]invalid mb type in I Frame at 0 14
..

I have two Technotrend DVB-C 1500 cards. The channels which do not work
ok are defined like this in channels.conf:
CANAL+:266000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_128:518:686:309
CANAL+ FILM:266000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_128:512:650:301
CANAL+ FILM2:266000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_128:515:682:308
CANAL+ SPORT:266000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_128:514:670:305
C MORE FILM:266000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_128:519:689:313
Cartoon
Network:266000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_128:700:701:402

however fairly similar channels do work ok.. (has encryption, has QAM128
etc)

Discovery:138000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_128:900:901:406
Animal
Planet:138000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_128:1000:1001:407
Sky News:138000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_128:515:652:1013
Bloomberg English
TV:138000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_128:1560:1520:5
TV4:138000000:INVERSION_AUTO:6900000:FEC_NONE:QAM_128:1049:1048:1040

266Mhz is the same frequency my motherboard fsb runs (Asus A7V266-EX)  ;-)

Any ideas how to debug this?

--Kari