[mythtv] DVB: playback and live TV

Kenneth Aafloy ke-aa at frisurf.no
Fri Aug 22 19:16:25 EDT 2003

Neil Symington wrote:
> card. Are there any patches I should have applied for DVB watching?

CVS should contain what you need.

> When watching live TV, sometimes it gives me the same symptoms as for
> playback, and sometimes it works. When it works, changing channel will
> usually mess things up - the screen goes black and I see these messages
> mythbackend:
> IOBOUND - blocking in ThreadedFileWriter::Write()
> Backend stuffed up in RequestRingBufferBlock

Which version of QT are you using?
The recomended is 3.2 as it contains a lot of fixes.
I'm a bit stumped by the playback of recording not working,
do you have any suggestions on this, Isaac?

> The recorded files are excellent when viewed with mplayer, so the DVB
> is OK. I'm running an Athlon 1700XP with Mandrake 9.1. Myth is compiled
> 'pentiumpro' and I've compiled with debugging flags. If I'm not missing
> patchees, could someone look at these to see if they understand what's
> happening?

I'm trying...

> [New Thread 131081 (LWP 5471)]
> [New Thread 147466 (LWP 5472)]
> 2003-08-21 23:20:16 adding: sym as a player 1
> Program received signal SIGINT, Interrupt.

What happens if you try to wait a little longer here?
"Backend Stuffed up in....."?

A missing message: 'filtering pids: <Same numbers as SetPID>'
Indicates that the card is not feeding data to the backend.
Also, right after that you should see Audio/Video parameters.
That is what you see when it's working, right?

Could you try this patch?


Index: dvbchannel.cpp
RCS file: /var/lib/mythcvs/mythtv/libs/libmythtv/dvbchannel.cpp,v
retrieving revision 1.4
diff -u -r1.4 dvbchannel.cpp
--- dvbchannel.cpp      23 Jul 2003 16:01:42 -0000      1.4
+++ dvbchannel.cpp      22 Aug 2003 16:10:11 -0000
@@ -118,12 +118,7 @@
             // FIXME: This hurts no-one, but really,
             //   there should be a video/audio pair in the database.
-            if (i==0)
-                 set_ts_filt(demux_fd[i], pid[i], DMX_PES_VIDEO);
-            else if (i==1)
-                 set_ts_filt(demux_fd[i], pid[i], DMX_PES_AUDIO);
-            else
-                 set_ts_filt(demux_fd[i], pid[i], DMX_PES_OTHER);
+            set_ts_filt(demux_fd[i], pid[i], DMX_PES_OTHER);

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