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Full Version: NRecord tried to tune my QAM tuner to an ATSC channel, and vice-versa!
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Ok, this one is very weird. It's tough to follow myself, much less explain, so I'll just go explain the tuner setup and then list the events:

Tuners, in priority order:

Digital 1523: Hauppauge WinTV 885 BDA Tuner/Demod (QAM) - this is an HVR-1250 -
Digital 1524: WinTV HVR-950 BDA Tuner (ATSC) - this is an HVR-850 -
Analog 1: USB 2883 Device
Analog 2: Happauge WinTV 885 Video Capture (same device as digital 1523)

(only the digital tuners are involved with the issue, the analog tuners listed for sake of completeness.)

All channels involved here are merged between the QAM and ATSC tuners. I have verified that the tuning entries are correct in Devices, and that each channel works on each tuner.

Logical Channel 7 = QAM 92.546, ATSC 7.1
Logical Channel 11 = QAM 92.548, ATSC 13.4
Logical Channel 13 = QAM 93.553, ATSC 13.3


  1. At 18:58:58, Started watching Live TV on QAM tuner (1523). This is logical channel 7, QAM channel 92.546
  2. At 19:00, The Big Bang Theory started recording on the QAM tuner, on logical channel 11, QAM channel 92.548. All is well.
  3. At 19:30:00, The Big Bang Theory stops recording. LiveTV is still active. All is well.
  4. At 19:30:01.236, NRecord wanted to record "How I Met Your Mother" (logical channel 13) on the QAM tuner, but had to move because of LiveTV.
  5. At 19:30:01.338, NRecord determines correctly that it can move the recording to the ATSC tuner (1524), where it should be on ATSC 13.3.
  6. At 19:30:01.554, NRecord asks NDigitalHost-1524 to start the recording.
  7. NDigitalHost-1524: At 19:30:05.355, NDigitalHost tries to tune the ATSC tuner with a QAM tuning request!!! It tunes QAM channel 93.553, when it should tune ATSC 13.3! It even reports a signal lock, though to what I have no clue, there's nothing there...
  8. At 19:30:05.808, NRecord wanted to record another "Big Bang Theory" (logical channel 11); says it needs to move it because of LiveTV (this isn't really correct, it was provisionally scheduled on ATSC Tuner 1524, which is now in use for a recording; tuner 1524 SHOULD be recording on ATSC 13.3, and this new recording needs ATSC 13.4 so it should use the same tuner... but NRecord is confused, and has tuned 1524 to QAM 93.553)
  9. At 19:30:05.823, NRecord determines that it can move the recording to QAM Tuner 1523, which is still running LiveTV on physical channel 92, the same QAM channel needed for The Big Bang Theory (just like the 19:00 recording that just finished).
  10. At 19:30:05.876, NRecord asks NDigitalHost-1523 to start the recording.
  11. NDigitalHost-1523: At 19:30:05.877, NDigitalHost tries to tune the QAM tuner with an ATSC tuning request!!! It tunes ATSC channel 13.4, when it should stay on QAM 92 and access stream 548.
  12. NDigitalHost-1523: At 19:30:06.493, NDigitalHost determines that the LiveTV stream is no longer valid, since the tuner has changed frequencies, and stops handle 23.
  13. At 19:30:06.491, NRecord fails to renew the LiveTV lease on handle 23, and stops the stream. LiveTV ends.

So at this point, two shows are recording on separate tuners delivering no data, each tuned with a tuning string meant for the other tuner. As expected, both recordings are zero length, and get marked "Failed: No errors reported, but no data delivered."

At 20:00, both recordings end, other recordings begin, and the correct tuners are used with the correct tuning strings and all is well again.

Logs attached, along with my npvr.db3, so that you can check all the tuning and channel detail in my database. This seems like a bug which I've never run into before because until now I only had ATSC channels, and the tuning strings were exactly the same across my tuners. However, I know I'm not the only one with channels merged across tuners of different types, so maybe the problem is just in my setup. Yet the scenario to make this happen isn't going to occur every day, and we do see reports of mysterious "no data delivered" recordings from time to time, so maybe I've found something... only sub can know!

(edit: I got curious, having never looked in my npvr.db3, so I downloaded SQLiteSpy and had a look. Everything looks good to me in the CHANNEL_MAPPING table. Logical channel 11 is channel_oid 7036, and 13 is channel_oid 6940. Each has 4 tuning entries, each is correct for the given tuner. Tuner 1522 is disabled, it's the ATSC version of 1523)
sub, have you been able to look into this? I was hoping a fix for this scenario would make it into the upcoming release...
I tried to read through this the other day but my brain gave out about half way through Big Grin

I just had another look now and I'm pretty sure I've found the cause and fixed for the next release.
sub Wrote:I tried to read through this the other day but my brain gave out about half way through Big Grin
lol, sorry.... Big Grin
Quote:I just had another look now and I'm pretty sure I've found the cause and fixed for the next release.
cool, thanks!