Opened 15 years ago

Closed 15 years ago

#1873 closed defect (fixed)

DVB-T radio broken

Reported by: Aidan Thornton <makomk@…> Owned by: danielk
Priority: minor Milestone: 0.20
Component: mythtv Version: head
Severity: medium Keywords:
Cc: Ticket locked: no


Recording of DVB-T radio is broken in latest MythTV SVN trunk (I'm using r10024, but it goes back further than that). Playback in mythfrontend fails (black screen, no sound, then times out) - the final message on each attempt at opening the video file is:

2006-05-27 01:00:41.765 TV Error: nvp->IsPlaying() timed out

mplayer works, but reports no video. Mythbackend prints the following message repeatedly whilst recording a DVB-T radio station:

2006-05-27 00:59:25.871 DVBRec(0): Unknown PID 0x21

AFAICT, the problem seems to be that DVBRecorder::AdjustFilters sets the list of PIDs to be written to the output file from the PMT, then calls StartDummyVideo?(), which is what creates the dummy video PID. A new PMT with the dummy video PID included is created in StartRecording after the call to AdjustFilters returns, but it is never added to the list of PIDs to be written to the output file, so no video is recorded. Not sure how to fix this, though.

Attachments (1)

dvradiofix.diff (1.8 KB) - added by mythdev@… 15 years ago.
Patch to get DVB radio working again

Download all attachments as: .zip

Change History (6)

comment:1 Changed 15 years ago by mythdev@…

Looked at this while trying to understand the new approach - file attached fixes radio but I'm not sure if the fix is in the right place.

Also a) By observation - looking at ProgramMapTable::FindUnusedPID - I believe there are a couple of typos - the patch fixes these, but they were not needed to fix the radio in my case.

b) The existing code suggests the dummy video streams are in the G.A.N.T subdirectory of themes - in my case they are in the themes directory root - I may be out of sync with theme movements - the patch fixes this but ...

c) The actual fix is just to add the dumy pid to the writing pids list - ymmv :)

Changed 15 years ago by mythdev@…

Attachment: dvradiofix.diff added

Patch to get DVB radio working again

comment:2 Changed 15 years ago by Aidan Thornton <makomk@…>

I think the change to not search the G.A.N.T. theme directory is broken - the code to find and open the dummy video file (in DVBRecorder::RunDummyVideo) assumes the list of dirs to be searched contains two items, and it now contains only one, so presumably mythbackend would crash if the dummy video file was missing. Other than that, it seems to work.

comment:3 Changed 15 years ago by mythdev@…

wrt aidan's comments about the path part of the patch - this bit is definitely not needed/is wrong. I completely misunderstood the code :(

comment:4 Changed 15 years ago by danielk

Milestone: 0.20
Owner: changed from Isaac Richards to danielk

comment:5 Changed 15 years ago by danielk

Resolution: fixed
Status: newclosed

(In [10087]) Fixes #1873. Fixes DVB-T Radio, by writing fake video stream pid.

I didn't use the patch because it had some errors in it, but I added a one liner which should fix the problem.

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