[linux-dvb] Audio Dropout on DVB recordings - Air2PC

Blammo blammo.doh at gmail.com
Thu Mar 24 00:20:11 CET 2005


I apologize for the partial crosspost, but of the two halves of this
problem, the DVB one is causing me the most grief.

I'm using MythTV to record from an Air2PC card, latest CVS DVB
drivers, 2.6.10 kernel, Fedora Core 3.

I'm getting audio dropouts, part-way through a recording, which then
fail to correct. This leaves me with recordings which have perfect
video the entire length, but no audio after the point of no recovery.

Closing and re-opening the card re-init's the stream, and the audio
returns, which makes me think this is correctable.

I have a nice strong signal. I've tried both PS and TS mode, no change.

Here's the majority of my other post. ( I realize my logs are from
3/1, but the behavior has not changed)

-------------------------

In all cases, either stopping and starting the recording, or leaving
and coming back to live TV restored the audio. There were NO
detectable video artifacts, breaks, etc, to make me think it might be
signal quality related.

One dropout, while watching LiveTV, was at 21:46:55, so I'm going to
post the logs from then. The audio dropped out after a commercial
break, and didn't come back. Exiting to menu, and back to LiveTV
restored the audio.

I'm going to post back to 21:30 when we started, so you can see the
signal strength, that it didn't lose signal, etc. From what I can tell
fda0 is a strong signal:


2005-03-01 21:30:51.456 DVB#0 DVB Signal Monitor Stopped
2005-03-01 21:30:55.432 DVB#0 DVB SI Table Parser Started
2005-03-01 21:30:55.433 DVB#0 Using DVB card 0, with frontend Nextwave
nxt2002 VSB/QAM frontend.
2005-03-01 21:30:55.435 DVB#0 DVB Signal Monitor Starting
2005-03-01 21:30:55.438 DVB#0 Signal Locked
2005-03-01 21:30:55.878 DVB#0 Signal Lost
2005-03-01 21:30:56.135 DVB#0 Signal Locked
2005-03-01 21:30:56.437 DVB#0 DVB signal fda0 | snr e47e | ber    0 | unc    0
2005-03-01 21:30:56.442 DVB#0 Status: LOCK.
2005-03-01 21:30:56.444 DVB#0 Multiplex Locked
2005-03-01 21:30:57.563 DVB#0 Successfully tuned to channel 15_1.
2005-03-01 21:30:57.569 DVB#0 Recorder: Card opened successfully
(using PS mode).
2005-03-01 21:30:57.575 DVB#0 AutoPID selecting PID 49, MPEG-2 Video
2005-03-01 21:30:57.577 DVB#0 AutoPID selecting PID 52, AC3 Audio
2005-03-01 21:30:57.578 DVB#0 AutoPID Complete - PAT/PMT Loaded for service
2005-03-01 21:30:57.583 DVB#0 Service is FTA
2005-03-01 21:30:57.585 DVB#0 Adding pid 49
2005-03-01 21:30:57.586 DVB#0 Adding pid 52
2005-03-01 21:30:57.591 DVB#0 Data read from DMX - This is for
debugging with transform.c
2005-03-01 21:39:08.769 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:39:08.801 DVB#0 PID 52 _continuity_count 4 cc 9
2005-03-01 21:41:09.300 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:41:09.338 DVB#0 PID 52 _continuity_count 1 cc 7
2005-03-01 21:41:09.387 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:41:09.390 DVB#0 PID 52 _continuity_count 15 cc 1
2005-03-01 21:46:36.433 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:46:36.474 DVB#0 PID 52 _continuity_count 6 cc 12
2005-03-01 21:46:36.517 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:46:36.519 DVB#0 PID 52 _continuity_count 4 cc 1
2005-03-01 21:46:36.522 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:46:36.523 DVB#0 PID 52 _continuity_count 9 cc 1
2005-03-01 21:46:52.909 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:46:52.914 DVB#0 PID 52 _continuity_count 3 cc 1
2005-03-01 21:46:55.799 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:46:55.805 DVB#0 PID 52 _continuity_count 4 cc 10
2005-03-01 21:46:55.884 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:46:55.885 DVB#0 PID 52 _continuity_count 3 cc 1


At this point the audio is gone, so I flipped out to the menu, and back in again


2005-03-01 21:47:06.594 Closing DVB recorder
2005-03-01 21:47:06.596 Closing DVB channel
2005-03-01 21:47:06.752 DVB#0 DVB Signal Monitor Stopped
2005-03-01 21:47:08.822 DVB#0 DVB SI Table Parser Started
2005-03-01 21:47:08.824 DVB#0 Using DVB card 0, with frontend Nextwave
nxt2002 VSB/QAM frontend.
2005-03-01 21:47:08.825 DVB#0 DVB Signal Monitor Starting
2005-03-01 21:47:09.398 DVB#0 Signal Locked
2005-03-01 21:47:09.829 DVB#0 DVB signal fe10 | snr e44e | ber    0 | unc    0
2005-03-01 21:47:09.834 DVB#0 Status: LOCK.
2005-03-01 21:47:09.836 DVB#0 Multiplex Locked
2005-03-01 21:47:11.018 DVB#0 Successfully tuned to channel 15_1.
2005-03-01 21:47:11.023 DVB#0 Recorder: Card opened successfully
(using PS mode).
2005-03-01 21:47:11.026 DVB#0 AutoPID selecting PID 49, MPEG-2 Video
2005-03-01 21:47:11.028 DVB#0 AutoPID selecting PID 52, AC3 Audio
2005-03-01 21:47:11.029 DVB#0 AutoPID Complete - PAT/PMT Loaded for service
2005-03-01 21:47:11.029 DVB#0 Service is FTA
2005-03-01 21:47:11.031 DVB#0 Adding pid 49
2005-03-01 21:47:11.033 DVB#0 Adding pid 52
2005-03-01 21:47:11.112 DVB#0 Data read from DMX - This is for
debugging with transform.c

It was fine until 21:59:05, when the station flipped aspect (I hate
seeing them do that before the end of the show) at which time we lost
audio again:


2005-03-01 21:59:05.039 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:59:05.070 DVB#0 PID 52 _continuity_count 7 cc 13
2005-03-01 21:59:05.124 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:59:05.125 DVB#0 PID 52 _continuity_count 6 cc 1
2005-03-01 21:59:07.920 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:59:07.926 DVB#0 PID 52 _continuity_count 10 cc 0
2005-03-01 21:59:08.004 DVB#0 WARNING - Transport Stream Continuity
Error. PID = 52
2005-03-01 21:59:08.009 DVB#0 PID 52 _continuity_count 9 cc 1
2005-03-01 22:00:19.900 Closing DVB recorder




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