[mythtv] DVB recording issues

Jesper Sörensen jesper at datapartner.se
Wed Mar 16 13:47:56 UTC 2005

Peter wrote:

>1) Using PS mode, sometimes I loose sound in a recording. If I rewind
>a bit I still loose sound at the same point, leading me to believe
>there is no sound in the recording. It appears to affect recordings
>randomly, on either of my two DVB-T cards on (seemingly) any channel.
>>From reading this and the -user list, it sounds as though running in
>TS mode might help this issue, and TS mode is the way forward anyway.
>2) So onto TS mode, while playing back the recording in myth and
>pressing the 'i' key, the display says the recording is only ~30sec to
>2 mins (the time varies). However the file on the file system appears
>to have a valid end time and size, suggesting that the recording
>should be longer than the ~2mins that the osd claims it is. Playing
>the same file in mplayer, and mplayer crashes at approx the ~30sec to
>2mins timeframe. This leads me to believe the recording is corrupt
>(for some reason), rather than a playback issue.

Peter, and all other DVB users out there:

I think both of these issues are "known problems", but all the devs are 
busy people and as far as I know noone really knows what's causing these 
probs (and therefore it's naturally hard to fix them). Also with all 
these bug reports flying around on the mailing list it's a bit hard to 
get the big picture and things tend to get lost in the noise so may I 
suggest that you go to http://www.mythtv.org/bugs/ and we take it from 
there? You can always drop a note to the -dev list with a link to the 
bug to wake everyone up if there's something new.

It sounds like #2 could be related to 
"http://www.mythtv.org/bugs/show_bug.cgi?id=221". Not sure if #1 is 
related to e.g. "http://www.mythtv.org/bugs/show_bug.cgi?id=199" or not 
(create a new bug if unsure).

Then people could add comments with data points which hopefully will 
help us figure out where the problem lies. Some things that would be 
interesting to know is:

1) Any kind of pattern to the problem: TS/PS? Only certain channels 
(PCRPID different from video PID?) Certain times (commercial break? 
format change? pid change?)
2) Is the problem in the recorder/backend or in the player/frontend? If 
possible try playing a recording with mplayer/xine etc. and see if it 
works there. Also try playing an old recording in Myth to see if the 
player can handle that?
3) Is it a DVB only problem or does it happen with ATSC, ATSC with DVB 
drivers, analog cards?
4) Interesting log msgs when the problem occurs? Backend log? Frontend 
log (-v all)? Mysql log? Syslog? Dmesg? And please don't spam us with 
logs, pick the interesting parts, if there are any... :-)

I'm sorry if I'm stating the obvious or something but I just feel it 
would be nice with a better structure for all the info flying around. 
Good bug reports => quicker fixes :-)

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