Pre Padding fails for 10pm recordings (starts late instead of early)

[Stereodude]

This one is odd, but it's burned me two nights in a row.

I have GB-PVR (1.4.7) set to pad recordings by 3 minutes at the start and end. Yesterday and tonight I had shows set to record at 8pm, 9pm, and 10pm. Tonight, the 8pm show recorded 7:57-9:03pm. The 9pm show recorded 8:57-10:03pm. The 10:00pm and 10:01pm shows both recorded from 10:03-11:03pm. Last night the exact same scenario was setup and the same thing happened except they were both 10:00pm recordings (instead of a 10:00pm and a 10:01pm). :mad:

I have 4 total tuners (2 HDHR) and have "Enable Multi-Record support" checked.

I've been using GB-PVR for a long time and never encountered this issue in the past. :confused:

I also ran a test earlier today where I set the system to record 3 hours in a row on two channels simultaneously and it worked fine.

[Stereodude]

Ok, well I went through the logs and found a pile of errors. I have copied and pasted them into a file and attached it to this post.

These two errors occur at ~9:57pm

Code:

2010-09-21 21:57:00.189    ERROR    [5]    Unexpected error checking tuning on back-to-back multirecords
2010-09-21 21:57:00.189    INFO    [5]    Found new programme requiring recording: NCIS: Los Angeles *    (158)
2010-09-21 21:57:00.189    VERBOSE    [5]    Changing to channel (GBPVR.Backend.Common.NullTunerController): 0
2010-09-21 21:57:00.189    VERBOSE    [5]    Requesting IRecordingSource to start recording: D:\HDTV\NCIS Los Angeles\NCIS Los Angeles_20100921_22002300.mpg
2010-09-21 21:57:00.189    VERBOSE    [5]    start recording @1
2010-09-21 21:57:00.189    VERBOSE    [5]    start recording @2
2010-09-21 21:57:00.189    VERBOSE    [5]    BDARecordingSource about to start recording  oid:1 channel: file:D:\HDTV\NCIS Los Angeles\NCIS Los Angeles_20100921_22002300.mpg
2010-09-21 21:57:00.189    ERROR    [5]    Error starting recording: System.ArgumentOutOfRangeException: Length cannot be less than zero.
Parameter name: length
   at System.String.InternalSubStringWithChecks(Int32 startIndex, Int32 length, Boolean fAlwaysCopy)
   at System.String.Substring(Int32 startIndex, Int32 length)
   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, Int32 commonInterface)
   at NativeUtilities.BDARecorder.StartRecording(String cardType, Int32 board, String filename, IntPtr hwnd, ChannelTuning channelTuning, Int32 lnbLOF1, Int32 lnbSwitch, Int32 lnbLOF2, Int32 diseqc, Boolean powered, Int32 commonInterface)
   at GBPVR.Backend.Common.BDARecordingSource.startRecording(IRecordingSourceConfiguration config, Int32 qualitySetting, String filename, ChannelTuning channelTuning, Int32 minutes, Boolean useStreamingEngineIfAvailable)
   at GBPVR.RecordingService.x93f60a55016d55c4.xcba1f05fb5a46d5f()
2010-09-21 21:57:00.204    ERROR    [5]    Unexpected error checking tuning on back-to-back multirecords
2010-09-21 21:57:00.267    VERBOSE    [5]    BDARecordingSource about to start multi-record  oid:2 channel: file:D:\HDTV\Detroit 1-8-7\Detroit 1-8-7_20100921_22002300.ts
2010-09-21 21:57:00.267    ERROR    [5]    Caught unexpected exception: System.ArgumentOutOfRangeException: Length cannot be less than zero.
Parameter name: length
   at System.String.InternalSubStringWithChecks(Int32 startIndex, Int32 length, Boolean fAlwaysCopy)
   at GBPVR.Backend.Common.BDARecordingSource.StartMultiRecord(String filename, ChannelTuning channelTuning)
   at GBPVR.RecordingService.x93f60a55016d55c4.xcba1f05fb5a46d5f()

Then the follow error repeats every ~250ms until 10:03pm when the 9pm recording stops.

Code:

2010-09-21 21:57:00.939    ERROR    [5]    Unexpected error checking tuning on back-to-back multirecords
2010-09-21 21:57:00.939    VERBOSE    [5]    BDARecordingSource about to start multi-record  oid:2 channel: file:D:\HDTV\Detroit 1-8-7\Detroit 1-8-7_20100921_22002300.ts
2010-09-21 21:57:00.939    ERROR    [5]    Caught unexpected exception: System.ArgumentOutOfRangeException: Length cannot be less than zero.
Parameter name: length
   at System.String.InternalSubStringWithChecks(Int32 startIndex, Int32 length, Boolean fAlwaysCopy)
   at GBPVR.Backend.Common.BDARecordingSource.StartMultiRecord(String filename, ChannelTuning channelTuning)
   at GBPVR.RecordingService.x93f60a55016d55c4.xcba1f05fb5a46d5f()
2010-09-21 21:57:01.142    ERROR    [5]    Unexpected error checking tuning on back-to-back multirecords
2010-09-21 21:57:01.142    VERBOSE    [5]    BDARecordingSource about to start multi-record  oid:2 channel: file:D:\HDTV\Detroit 1-8-7\Detroit 1-8-7_20100921_22002300.ts
2010-09-21 21:57:01.142    ERROR    [5]    Caught unexpected exception: System.ArgumentOutOfRangeException: Length cannot be less than zero.
Parameter name: length

Any help would be appreciated. Thanks!

[sub]

You could try disabling multi-record to see if the padding works more like you'd expect.

[Stereodude]

You could try disabling multi-record to see if the padding works more like you'd expect.

I recorded 3 hours in a row on two channels simultaneously with back to back to back to back recordings yesterday morning and it worked perfectly with the expected pre & post padding. I have attached the log here. I went back and took a look at the logs for it and I did notice that the same "ERROR [5] Unexpected error checking tuning on back-to-back multirecords" appears when the recordings start on a tuner that's not already in use. I'm not sure that's the problem since that error occurs during both successful and unsuccessful sessions.

If I disable multi-record will it need 4 tuners to record two channels with back to back shows?

I will try that, but I guess I'm trying to understand what's special about recording two shows at 10pm that would cause the "length" to be less than zero for one since that seems to be the important error here.

Thanks!

[Stereodude]

Well, I recorded one show at 8pm, one at 9pm and two at 10pm without any error last night with "multi-record" disabled. Unfortunately though, it does use two tuners to record back to back shows on the same channel if you're using padding.

I'm not sure if 4 tuners is enough for the shows I want to record this year if I can't use "multi-record". I don't really want to buy another HDHomerun because "Length" is less than zero. :p

[sub]

Unfortunately there isnt really much we can do about it now. I stopped development on GBPVR a year ago.

I think the same problem occurs with NPVR, but I do intend to fix it in the near future, so it might be worth planning to move to NPVR in the near future to correct this.