[linux-dvb] Re: "Video datastream brocken" - origin (maybe) found

[Wolfgang Fritz <wolfgang.fritz@gmx.net>]

Johannes Stezenbach wrote:
> Helmut Auer wrote:
> 
>>Andreas Share wrote:
>>
>>
>>>after tons of debug-logs i have found (maybe) the reason for the "Video
>>>datastream broken" errors (and maybe UPT errors too).
>>>
>>>The problems, at least with my skystar2 cards, are caused by an 
>>>inconsistend
>>>timing (different runtime) between frontend and demux ioctl´s.
>>
>>Are the DVB-driver developers aware of this problem ?
>>I am surprised to see no comments here. For some VDR-users the UPT- or 
>>datastream broken error is a great pain.
> 
> 
> Andreas' experimental code does arbitrary changes to certain
> timings until it works for *him*. That's not a solution, but
> it certainly indicates where the problem might come from.
> 
> There were posting here suggesting bugs with vdr's handling
> of FE_GET_EVENT, maybe that's the way to go?
> 

I've changed the FE_GET_EVENT handling in VDR to use poll() and in this
case I see short 0x1f-events (FE_HAS_LOCK bit set) of abt 100ms on
channels I can't tune to (I had a bogus entry in my channels.conf).

The original VDR lock detection handles this as a valid lock, which is a
bit sloppy in my opinion, but I would like to know if an application has
to expect such "spikes" and do some filtering on frontend events?

Other question: There _seems_ to be some evidence that it is dangerous
if you set (change?) filters when the frontend is not locked. Could that
be possible?

System: 1 Nexus-s rev. 2.1, one Skystar2 rev2.6c, dvb-kernel 2.4 CVS branch.

Wolfgang


> Johannes
> 
>