[mythtv] DB Error (blank frame list insert) and ERROR:file I/O

Chris cisip at sprintmail.com
Wed Mar 26 20:08:13 EST 2003


My system just switched to recording 2 different shows since there were
two different shows scheduled at 8 pm.  It did the Changing from None to
REcordingOnly twice without any DB error.  I expect both shows will be
fine when I seek while playing them later.  So it seems the problem only
occurs if I have one show scheduled for recording.  Some how it is not
cleared off the record list and is being handed to the second
encoder.    Also "top" did not show any significant change in CPU usage
indicating that it was recording 2 shows after all at 7 PM when it
should have been recording only one (the second show being the first
show all over again).  

On Wed, 2003-03-26 at 19:50, Chris wrote:
> As far as I can tell, (i am looking at it on the tv screen) there is
> only one "mythbackend" under the COMMAND column. It says 16 for FRI, 0
> for NI, 82536 for SIZE, 64M for RSS, 6720 for SHARE, S for STAT, 75.4
> for %CPU, 12.8 for %MEM.
> 
> I am running an AMD Athlon XP 2400+ with 512 MB RAM.  I think a cpu
> usage of 74 percent is a bit high if mythbackend is only recording one
> show.  I think you are right, mythbackend might be recording the show
> twice and simultaneously to the same file.  I am not a programmer but I
> wonder if it is a timing issue.  Maybe if a delay is introduced before
> the second encoder is handed the next show to be recorded?  
> 
> 
> On Wed, 2003-03-26 at 18:27, Bruce Markey wrote:
> > Chris wrote:
> > > I am using one pc with two tuners.  Sometimes, i do get only one current
> > > recording in the Watch a Recording menu and at the same time not be able
> > > to watch live tv (it claims all tuners are busy even though Watch a
> > > Recording only shows one currently being recorded show).  Interestingly,
> > > though, this problem  does not happen all the time.  I can play all the
> > > shows I record. I cannot seek on about half of them.  
> > 
> > When you notice this again, run "top" and see if there are
> > two mythbackend processes using significant CPU time. If
> > this happens on a two tuner machine, both processes would
> > be trying to write to the same file. Disk writes are in big
> > clusters of blocks  and the process that writes last would
> > win so the file might almost be viewable. But if different
> > parts of the file were written by a different process the
> > frame alignment, timecodes and frame numbers would be messed
> > up and playback would certainly be terribly broken.
> > 
> > --  bjm
> > 
> > 
> > 
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-- 
Chris <cisip at sprintmail.com>



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