[vdr] Re: Multiple crashes while recording

[Emil Naepflein <Emil.Naepflein@philosys.de>]

On Thu, 30 May 2002 13:55:00 +0200, Norman Beck <norman.beck@web.de>
wrote:

> May 26 23:57:52 vdr vdr[1837]: ERROR: video data stream broken
> May 26 23:57:52 vdr vdr[1837]: initiating emergency exit
> May 26 23:57:52 vdr vdr[589]: emergency exit requested - shutting down

This is exactly the problem I had sometimes. I now changed the length of
the timeout and also just exit the thread when this happens. This at
least doesn't harm the other recordings running.

> This happened a few times while recording but each time caused 
> by a broken video stream.

This shouldn't happen during normal recordings. Please check whether the
SNR is high enough. I find patches showing the SNR in the archive.

> 
> At the moment I'll try the hack suggested by Emil -- thanx to him :-)

My hack targets only the case where stations stop sending during
recordings like Kinderkanal. It will also help on reception problems in
avoideing the restart, but the recording which caused the the exit
previousely will be broken.

I also thought about a different recovery strategy. It seems to me that
sometimes on poor reception the DVB card just stops to deliver data even
the reception is ok again. The emergency exit fixed this. But my
experience with the primery card is that switching to a different
channel and back is just good enough to fix that. May be just retuning
the station is enough. 

With this strategy we could use a much shorted timeout because when the
DVB card stops delivering data for a few seconds we really know that
something bad is going on here. Retuning the channel would be fast. And
if this tuning problem persists for some time the corresponding threads
can be stopped. 

As I currently don't know the corresponding code good enough I didn't
implement anything yet. But may be Klaus can improve the recovery
strategy in the future.

Emil