[vdr] Re: Can't record MPEG1 ?

[Andreas Schultz <aschultz@cs.uni-magdeburg.de>]

On Tuesday 30 July 2002 12:45, Klaus Schmidinger wrote:
> Karsten Mueller wrote:
> > Hi again folks,
> >
> > while editing a recorded movie, some strange errors appeared in my

The syslog indicates that zou where recording something. What do you mean by 
"editing a recorded movie"? Did you just go through it and set cut marks or 
did you already start the acctual cutting thread?

 syslogs:
> >  > Jul 29 23:08:09 player vdr[3033]: recording VDR file to
> >
> >    '/video/%Frau_2_sucht_Happy_End/2002-07-28.00.40.99.99.rec/002.vdr'
> >
> >  > Jul 29 23:08:34 player kernel: VFS: Disk change detected on device
> >
> >    ide0(3,64)
> >
> >  > Jul 29 23:08:34 player kernel: VFS: Disk change detected on device
> >
> >    ide0(3,64)
> >
> > I did NOT change neither DVD nor CD during the editing process, I did
> > not even touch it...
>
> I also observed this once or twice, but have no explanation for them.
> They don't come from VDR, though.

I would guess that something (most probably a script activated by cron) hit an 
auto-mount point for a cd or similar. This would result in the kernel trying 
to access the device and thus detecting any previous media change.

> >  > Jul 29 23:08:34 player vdr[2951]: ERROR: can't record MPEG1!
> >
> > What the heck is this ? Of course VDR can't record MPEG1 and nobody
> > wanted it to do so ...(?)
>
> Looks like you have a weak signal, so the data is somewhat distorted
> and while scanning it, VDR "believes" it found an MPEG1 header.

It could also be related to the "Disc change" message. Accessing an empty CD 
ROM drive can sometimes take a considerable amount of time. This would also 
fit in with previous report about MPEG1 errors under heavy system load, 
especialy when you did have a cutting _and_ a recording thread running at 
that time.
It would appear as if we are loosing TS packets under such circumstances.

Andreas
-- 
Andreas Schultz <aschultz@cs.uni-magdeburg.de>
Student of computer science

"In accordance with plans for Linux OS world domination
      infiltration of governments is vital (:-))."