[mythtv-commits] Ticket #13247: Backend won't change inputs with PVR-150 - regression from 27.6

[MythTV]

#13247: Backend won't change inputs with PVR-150 - regression from 27.6
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     Reporter:  ltskinol@…            |      Owner:  jyavenard
         Type:  Bug Report - General  |     Status:  new
     Priority:  major                 |  Milestone:  needs_triage
    Component:  MythTV - Recording    |    Version:  v29.1
     Severity:  medium                |   Keywords:
Ticket locked:  0                     |
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 I have mythtv 29.1 installed on Arch Linux with a PVR-150 card.  That card
 has multiple inputs and I'm using the Tuner and Composite 1 inputs for two
 different sources of TV.  When I upgraded from a Gentoo 28/fixes release
 to 29.1 on Arch, Myth has refused to consistently switch between the two
 inputs - always insisting on recording on the first-defined input.
 Neither live TV nor recordings worked.

 For the PVR-150, you define two tuners (both with the same /dev/video0
 device), then associate two listing sources, one per tuner.  If the
 listing sources have different ranges of channels (with the tuner, say,
 being 2-99 and the composite being 100-199), Myth should (and did) switch
 between inputs based on changing the channel number.

 After _much_ banging of head, I decided to dive into the code, and found a
 mistake/regression from the release of 27.6 to 28.0.  It's in tv_rec.cpp,
 around line 3540.  The change is:

      if (!inputname.isEmpty())
      {
 -        curCardID = channel->GetInputID();
 -        newCardID = channel->GetInputID();
 +        curInputID = channel->GetInputID();
 +        newInputID = channel->GetInputID();
          LOG(VB_GENERAL, LOG_INFO, LOC + QString("HW Tuner: %1->%2")
 -                .arg(curCardID).arg(newCardID));
 +                .arg(curInputID).arg(newInputID));
      }

 -    if (curCardID != newCardID ||
 !CardUtil::IsChannelReusable(genOpt.cardtype))

 This is 108d12d6507a9b6f61c81a7335e9c40fba96dce5 ( gigem committed on Jul
 12, 2015 ) and it's obviously incorrect.  curInputID and newInputID now
 grab the same value, and therefore are always the same.  The last if()
 statement then doesn't execute, which causes the input change to not
 happen.  This looks like a mistake in the refactoring.

 I don't know what the proper fix is, but if I hack in "curInputID = 55;",
 thus ensuring that the last if() statement executes, the input changes as
 expected.

 Please fix.

 One other thing: this fixes the input switch when starting a recording,
 but doesn't address a (perhaps) related bug in that inputs also don't
 switch when changing channels with live TV.  I don't know where to look
 for that bug.

 Also, tv_rec.cpp is identical in this area from version 28.0 through the
 current head.

 Thanks.

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Ticket URL: <https://code.mythtv.org/trac/ticket/13247>
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