Occasional zero-length recordings

[SP0]

Generally GB-PVR records fine for me, but sometimes I get zero-length files instead of a recording.

Setup:
- Hauppauge Nova-TD Tuner (dual)
- Nebula DigiTV board
- Vista
- initiating recordings from recurring settings in the web interface
- my own postprocessing.bat to do videoredo, but the problem is before that (I put a DIR command into the batch file and can see that on call to this, the file is zero length)

Log entries in GBPVRRecordingService.exe.log:
[SIZE="1"]2008-09-28 13:30:00.088 INFO [5] Found new programme requiring recording: EastEnders (306)
2008-09-28 13:30:28.510 INFO [5] Recording is unusually small. Giving second chance: D:\TVRadio\NEW\EastEnders_20080928_13301525.mpg (0)
2008-09-28 15:26:01.719 INFO [15] Running postprocessing.bat on: D:\TVRadio\NEW\EastEnders_20080928_13301525.mpg
2008-09-28 15:26:06.719 INFO [15] Commercial Detection has completed.[/SIZE]

I don't know what this "second chance" means ... and the programme is probably about 2 hours long so the call to the postprocessing.bat is at about the right time. Maybe it's successfully rerecording but messing up the file operations so I get the failed one not the right one?

Then postprocessing.bat found this:

[SIZE="1"]28/09/2008 15:26 0 EastEnders_20080928_13301525.mpg
1 File(s) 0 bytes
0 Dir(s) 71,586,164,736 bytes free[/SIZE]

In GBPVRRecordingService.exe-native.log I see this (you can see that it was recording something else in parallel):
[SIZE="1"]2008-09-28 13:20:00.479 INFO BDARecorder:::StartRecording(Nebula PCI BDA DVB-T (1.02), 1, D:\TVRadio\NEW\Roswell_20080928_13201415.mpg, T:C22,481834,0,0,8~NID:12293~ONID:9018~TSID:8197~P:8448~V:570~A:571~L:eng~PMT:267~LCN:29~PCR:8190~N:>E4)
2008-09-28 13:30:00.088 INFO BDARecorder:::StartRecording(Hauppauge Nova-TD Tuner 1, 1, D:\TVRadio\NEW\EastEnders_20080928_13301525.mpg, T:C25,505834,0,0,8~NID:12293~ONID:9018~TSID:4100~P:4164~V:600~A:601~L:eng~PMT:4164~LCN:1~PCR:600~N:>BBC ONE)
2008-09-28 13:30:29.994 INFO BDARecorder:::StartRecording(Hauppauge Nova-TD Tuner 1, 1, D:\TVRadio\NEW\EastEnders_20080928_13301525.mpg, T:C25,505834,0,0,8~NID:12293~ONID:9018~TSID:4100~P:4164~V:600~A:601~L:eng~PMT:4164~LCN:1~PCR:600~N:>BBC ONE)
[/SIZE]

I also noticed this but it may be unrelated (is it something I have to fix also?):

[SIZE="1"]2008-09-28 00:06:01.010 INFO [10] Auto-Updating EPG
2008-09-28 00:18:43.416 ERROR [10] Unexpected failed in DvbEpgReader.LoadChannels(): GBPVR.Backend.Common.GbpvrException: Failed to locate configured BDA capture device
at NativeUtilities.BDARecorder.StartRecording(String cardType, Int32 board, String filename, IntPtr hwnd, ChannelTuning channelTuning, Int32 lnbLOF1, Int32 lnbSwitch, Int32 lnbLOF2, Int32 diseqc, Boolean powered, Boolean previewMode)
at NativeUtilities.BDARecorder.StartRecording(String cardType, Int32 board, String filename, IntPtr hwnd, ChannelTuning channelTuning, Int32 lnbLOF1, Int32 lnbSwitch, Int32 lnbLOF2, Int32 diseqc, Boolean powered)
at GBPVR.Backend.Common.DvbEpgReader.LoadChannels(IEpgUpdateProgressCallback callback)[/SIZE]

Ideas welcomed!
Thanks

[sub]

Its most likely because the device has failed to lock onto a signal, so no data has been delivered to GB-PVR for writing to the file.

Zip and attach the GBPVRRecordingService.exe.log/GBPVRRecordingService.exe-native.log, and the name/time of a failed recording and I'll take a look.

[SP0]

Logs attached. Look for "Eastenders" as shown in the message above.
[ATTACHMENT NOT FOUND]

[sub]

Sorry, you'll need to reset your logging level back to debug, and repost the logs next time it happens. Those logs previous dont have enough info.

[SP0]

OK, I set up three simultaneous recordings - the one called "test2" came out zero length. Logs attached.

[martint123]

There looks to be a number of these, which looks like bad news.

2008-09-28 23:07:03.500 VERBOSE locked=0 present=0 strength=105 quality=-100

[SP0]

Can you give me slightly more hints about what "bad news" this might imply and how to fix? Thanks

[whurlston]

It's not locking onto the signal. Do you have an amplifier on the line? If so, try removing it. The numbers seem to indicate that the signal is overamped.

[martint123]

With my Hauppauge nova-t-500 If it show no lock, then the strength figure is a bit random.
-100 for quality would indicate to me a tuning or signal problem.

Can you try scanchannelsbda from http://www.hauppauge.co.uk/board/showthread.php?t=12082 to see what it reports for each MUX to see if one may be on reduced power or something?

[SP0]

scanchannelsbda ... to see what it reports for each MUX to see if one may be on reduced power or something?

Thanks, all.

That was very helpful - I found that there was an antenna problem and that the dual-tuner had somehow reverted to "diversity" mode, taking out another channel. I fixed the cabling and reset to dual-tuner mode - all seems fine now.