[mythtv] FFmpeg sync

David Engel david at istwok.net
Tue Oct 14 01:27:54 UTC 2008

On Mon, Oct 13, 2008 at 11:17:44PM +0200, Janne Grunau wrote:
> On Saturday 11 October 2008 21:30:46 David Engel wrote:
> > When I played an HDPVR 480p H.264 recording using mythfrontend, the
> > video played fine but I got no audio and the following log messages:
> >
> > 2008-10-11 13:43:40.745 Opening audio device 'default'. ch 1(1) sr
> > 12000 2008-10-11 13:43:40.745 Opening ALSA audio device 'default'.
> > 2008-10-11 13:43:40.763 AudioOutput Error: Unable to get period size
> > for playback: Invalid argument 2008-10-11 13:43:40.763 AudioOutput
> > Error: Unable to set ALSA parameters 2008-10-11 13:43:40.763 NVP:
> > Disabling Audio, reason is: Unable to set ALSA parameters
> Is that a recording with AAC audio? please send a complete log, the 
> error looks unrelated to the ffmpeg merge.

None of these problem occur without the ffmpeg patch.  This is with
svn r18673, BTW.

It looks like AAC.  It's whatever the HD-PVR generates by default from
the analog inputs.

See attached hdpvr.log.

Also see attached hdpvr2.log.  It's from a different recording and
results in an infinite loop.

> > This was with mythtv configured with "--enable-debug".  When I
> > rebuilt later with "--compile-type=debug", audio worked.
> could you try with with --compile-type=profile? --enable-debug shouldn't 
> be used.

What's wrong with just --enable-debug by itself?  What's the
recommended way to get debug symbols without losing optimzation?  If
that's suppoed to be compile-type=profile then it's very mislabeled.

> > When I played a QAM 720p MPEG2 recording using mythtv, it segfaulted
> > with with "--enable-debug" and "--compile-type=debug".  The backtrace
> > from the "--compile-type=debug" version is attached.
> The backtrace is useless, it looks if it is for two separate processes 
> and it misses symbols for libmythavcodec. And please don't cut the 
> message in which thread and function the segfault occured. If the error 
> with that recording is reproduceable a sample would help.

See attached mpeg2hd.log and mpeg2hd.gdb.

It happens with the kdfw2.mpg file I gave you for the other problem.
I'll send you the URL privately in case you don't still have it.

David Engel
david at istwok.net

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