[mythtv-commits] Ticket #231: DTV Signal Monitor needs to check PMT for on-air-status

MythTV mythtv at cvs.mythtv.org
Fri Aug 19 15:34:42 UTC 2005

#231: DTV Signal Monitor needs to check PMT for on-air-status
 Reporter:  stuarta at squashedfrog.net  |       Owner:  danielk
     Type:  defect                    |      Status:  new    
 Priority:  major                     |   Milestone:  0.19   
Component:  mythtv                    |     Version:  head   
 Severity:  medium                    |         Cc:                            |  
 I've been testing for the last few days.

 rev 7064 + signal monitoring patch.

 This fixes problem 3 in the list.

 When testing case 2 I was able to watch the other channel which timeshares
 with the channel that went off air, although I was tuned to the logical
 channel that was off air. I'm happy to leave this part as resolved for
 now, since proper handling of this requires finishing off interactive tv.

 (The following I've tested on 7082 + signal monitoring as well.)

 What no longer works is case 1. This is because the channels here in the
 UK logically go off air, but in practice they are still on air. What
 happens is the PMT is updated from a video + audio stream to only a data
 stream(s). So the signal monitoring isn't going to help us here.

 When the backend starts up on one of these "off air" channels, it can
 still get a valid signal lock, but there is no TV service present. There
 used to be a check in dvbchannel.cpp

             if (!chan_opts.pmt.OnAir()) {

                     ERROR(QString("Channel #%1 is off air.").arg(chan));
 return false;


 This did pick up this case. We will need to check something like this when
 entering live tv.

Ticket URL: <http://cvs.mythtv.org/trac/ticket/231>
MythTV <http://www.mythtv.org/>

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