[mythtv-commits] Ticket #12100: Ceton Tuner recording problems

[MythTV]

#12100: Ceton Tuner recording problems
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 Reporter:  Matt <matt@…>         |          Owner:  jyavenard
     Type:  Bug Report - General  |         Status:  infoneeded_new
 Priority:  minor                 |      Milestone:  unknown
Component:  MythTV - Recording    |        Version:  0.27-fixes
 Severity:  medium                |     Resolution:
 Keywords:                        |  Ticket locked:  0
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Comment (by mattlach@…):

 Replying to [comment:21 gigem]:
 > Various, somewhat random, thoughts.
 >
 > The Linux driver is not closed source.  The firmware is, but the
 firmware for the vast majority of cards is too.  In my few dealings with
 Ceton, they have been extremely helpful and cooperative.
 >
 > You don't say what firmware and driver versions you are using.  Make
 sure you have the latest or have very good reasons for not running the
 latest.
 >
 > I seriously doubt that the Windows utility makes any difference of
 consequence.
 >
 > If you suspect MythTV recorder issues, you need to run the backend with
 '-v record,channel' at a minimum.
 >
 > My bets are on intermittent DRM changes or signal quality being the
 cause of the truncated recordings.
 [[BR]]
 [[BR]]

 Don't get me wrong here.  Ceton seems like a good company and they make a
 solid product.   I was just speaking in general about the realities of
 developing commercial software in an environment of multiple priorities.
 In my brief stint as a Software QA guy (which I hope to never do again :p
 ) I have seen this first hand.

 I have not had a chance to look at my own logs, but the logs that OP
 posted clearly shows that something is coming in and changing the tuner
 channel to 0.   This was the big hint to me, as this is exactly what the
 Ceton Windows utility does when you fire it up, as part of its checking
 for a functioning tuner and cable card process.

 Where I suspect (but have not confirmed) the problem lies is in multiple
 networked hosts fighting over the same tuner.

 '''Scenario:'''

 MythTV is recording on tuner 0.  Ceton's Windows configuration utility
 then goes through it's checking routine, and switches the channel to 0.

 This is hardly a huge problem, as it should be up to the user to make sure
 they don't have multiple machines fighting over the same tuner, but what
 stood out to me was that this was happening even when the Ceton utility
 was not actively running, but for me the problem SEEMS to have gone away
 after uninstalling Cetons software and Windows Media Center from the other
 machines on the network.

 '''Theory:'''

 My working theory (which I have yet to confirm, and I am posting here
 hoping someone else will pick up and run with it, as I really don't have
 the time right now (I'm in the middle of both moving and switching jobs)
 is that the Ceton utility interrupts recordings by switching the channel
 to 0 during its testing sequence.  Also, as part of running the setup, the
 Ceton utility configures Windows Media Center to use the tuner, adding an
 additional variable to the equation.   After this, WMC may also be
 fighting with MythTV for the tuners, even when the Ceton utility is not
 actively running on Windows.

 It's just a theory at this time, but it is based on my problem seemingly
 going away (it hasn't been long enough yet) after uninstalling Ceton
 software and WMC from my windows boxes.

 It would be interesting to know how the handoff between tuners works when
 there are multiple hosts competing for tuners.  There isn't by any chance
 a controlled system architecture document for all this is there?  ;)

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Ticket URL: <https://code.mythtv.org/trac/ticket/12100#comment:22>
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