DVB EPG problems

[Chris Reynolds]

sub,
I've followed some of the threads on DVB EPG updates and wondered if you've seen a problem like this. I'm getting 'holes' in my schedule. I updated the harvest time to 480 to try to fill as many as possible but there were still some there. I had a log in the gbpvr log and found this error in there:

07/12/2005 21:12:23.937 VERBOSE [2] Date: 2005 12 14 19 0 0
07/12/2005 21:12:23.937 VERBOSE [2] Date: 2005 12 9 1 0 0
07/12/2005 21:12:23.937 ERROR [2] DVB EPG error reading xml: '', hexadecimal value 0x02, is an invalid character. Line 198, position 2.
07/12/2005 21:12:24.453 VERBOSE [2] getValue cached value: /settings/BDAUsePsiParser : true
07/12/2005 21:12:24.453 VERBOSE [2] getValue cached value: /settings/DvbEpgHarvestDuration : 480
07/12/2005 21:20:24.453 VERBOSE [2] getValue cached value: /settings/SaveDvbEpgXML : true

I've attached various logs and XMLs if that helps at all

Cheers

Chris

[sub]

It looks like the transport stream is incorrect at the point of the file, given the garbage in that field. Probably a momentary glitch in the signal.

<programme start="D1D1010000" duration="020000" channel="22080-Sky News">
<title>Sky News On The Hour</title>
<desc>Sky News brings you the latest home and international news, financial updates, top sngENGLISHP
Ăą</desc>
<unique-identifier>5640000001E8</unique-identifier>
</programme>

This would be enough to stop the Microsoft XML parser I use from loading and processing the XML.

This would in thoery be sorted if I was only processing the packets that have a correct CRC values, indicating the packet integrity is fine, but unfortunately I've not been able to calculate the same CRC values, so I'm not currently checking this. It'll be a flaw in the way I've interpreted the DVB specs, but as much as I've looked, the flaw does not seem obvious to me. Hopefully I'll get this in for the next release.

[Chris Reynolds]

sub,
Cool, thanks for the quick reply. It does seem to happen most times when I try to do an EPG update. It has to be said that I'm running off of an analogue aerial which (although amplified) runs about three times round the house via a DVD player, a VHS and a Sky box before it gets to the west wing of the house and the tuner card so I can imagine that the signal is perhaps not the cleanest in the world.
Good luck with the CRC checks and if you need any testing doing then shout.
Cheers
Chris

[sub]

Its actually common to have minor data corruptions in the transport stream, even with good signal strength, which is why they builtin this CRC mechanism so the receiver can determine whether it received a valid packet or not.

[Chris Reynolds]

Thanks for the comments. I'm going to switch back to bleb for the time being as there's too many holes in my EPG using the DVB stream. I know that you're tryin g to take a break from the releases but _if_ you were going to do one could you parse out any non-XML compliant chars from the stream before you load it into the DOMdoc to save it then faling to load? Although the time is probably better spent fixing the CRC check. God knows how you juggle your priorities on this job.

Thanks

Chris

[AlanC]

the generated xml file is trucated and log shows
DVB EPG error reading xml: System.Xml.XmlException: Unexpected end of file has occurred.
Evidence produced by restricting scan in config, but daily EPG scan across all devices and channels gives similar errors on about 50% of xml files.

[sub]

Cheers, I'm aware of this happening. Another user is trying to organise me a transport stream file so I can take a look at it here in the debugger.

[dazzyb2k3]

Nice to hear there's some news on this. I'd love to use DVB EPG but i've had to stay with XMLTV because of holes in the schedule. It's no biggie but nice to know it's being worked on

[sub]

I'm still waiting on that file, so no update yet.