[mythtv-users] deadlock in mythtranscode

[Yeechang Lee]

Robin Neatherway <robthebob at gmail.com> wrote back on 23 May:
> I'm using 0.19-fixes, and have a problem when trying to perform a
> lossless mpeg2 transcode:
> 
> mythtranscode -m -i topgear.mpg -o topgear_trans.mpg
> 2006-05-23 13:32:52.689 Using runtime prefix =3D /usr
> 2006-05-23 13:32:52.710 New DB connection, total: 1
> 2006-05-23 13:32:52.722 Enabled verbose msgs: important
> 2006-05-23 13:32:52.723 Couldn't deduce channel and start time from topgear
> Mux rate: 6.93 Mbit/s
> 2006-05-23 13:32:53.750 Deadlock detected.  One buffer is full when
>                 the other is empty!  Aborting

I also get this error message when lossless transcoding HD MPEG2
programs on my remote backend running 0.19-fixes (the ATrpms-128
version) on Fedora Core 3. This occurs whether I run the transcode
from mythfrontend or the command line.

To clarify, I don't *always* get it when lossless transcoding, but I
usually do. In my experience, lossless transcoding will usually fail,
but I've had a few programs for which transcoding succeeds (if it
fails, it fails and future retries don't make a difference). The ones
for which lossless transcoding succeeds fails are *usually* 1080i
programs, but I've had at least two 1080i transcodes
succeed. Conversely, the few successful transcodes have mostly been
with 720p.

I also get the error message when transcoding to MPEG4 but have only
tried once or twice here. (Correction: As it turns out the system was
still trying--and failing--to do lossless MPEG2 transcoding here. I've
set TV Settings|General|General (Jobs)|Default Transcoder to "High
Quality," and I've made what I thought are the appropriate changes to
the "High Quality" Transcoding recording profile to use MPEG4, but
according to the log messages on MythWeb the transcoding is still
doing "Autodetect," which of course is the lossless. What am I
missing?)

For what it's worth, the same remote backend happily commflags
(sometimes the commflagging doesn't pick up anything, typically on WB
or UPN programs, but I think that's an issue with the logo detector
routines). Speaking of which, another (very minor) issue with
transcoding, whether successful or not: While commflagging properly
provides updates to the status screen in mythfrontend ("35% completed
@ 41.1847 fps"), transcoding always sits at "0%" until just before it
completely finishes.

Suggestions?
-- 
Yeechang Lee <ylee at pobox.com> | +1 650 776 7763 | San Francisco CA US