[mythtv-users] Seeking problems with RTJPEG->MPEG4 transcoded files in 0.18.1-r2

Tom Felker tcfelker at mtco.com
Fri Jul 8 00:42:24 EDT 2005

Hi everyone,

I just upgraded from MythTV 0.15 to 0.18.1, and the frontend is having 
problems seeking.  If you don't seek, everything plays fine, but when you 
skip forward, it either just shows a black screen or skips forward way too 
far (41 minutes seems common).  If you then skip back into the gulf, it hangs 
briefly and then resumes playback at where it first skipped to.  If you skip 
forward, it hangs.  Thankfully, I can always press Escape to get back to the 

I record in RTJPEG due to a slow computer, and then transcode to MPEG4.  
Nothing else, I don't cut commercials by hand or do any editing before 
transcoding.  The problem doesn't effect files that haven't been transcoded.  

Scouring over verbose output from mythfrontend, one difference is that the bad 
output has some messages like the following.  (I could post full outputs, but 
they're long.)

2005-07-07 23:16:44.246 DoFastForward: Not enough info in positionMap, we need 
frame 75867 but highest we have is 32880
2005-07-07 23:16:44.429 SyncPositionMap prerecorded, from DB: 1097 entries
2005-07-07 23:16:44.429 DoFastForward: Still Not enough info in positionMap, 
we need frame 75867 but highest we have is 32880.  Will seek frame-by-frame

It may just be correlation, but just now deleting one of the affected shows 
seems to have caused other affected shows to work fine, for the time being.

Probably unrelated, but mythbackend does crash from time to time.

I've seen similar problems in the mailing list archives, but these referred to 
older versions, so this may be a new problem or perhaps the old ones weren't 
completely fixed.

Anyway, that's about all the info I have for now.  At the moment I'm fine just 
not transcoding.  Any help would be appreciated, though.

Have fun,
Tom Felker, <tcfelker at mtco.com>
<http://vlevel.sourceforge.net> - Stop fiddling with the volume knob.

Life is like an analogy.

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