[mythtv-users] Transcoding using the SVN build now results in a Green Squiggly Mess

[Osma Ahvenlampi]

On Sun, 2006-05-21 at 22:21 +0200, Niels Dybdahl wrote:

>         I have now upgraded to mythtv-0.19-128.rhfc4.at and that seem
>         to have solved the problem.

I just upgraded to that same version, but I still have the same problem.
However, I've managed to isolate a test case!

At http://www.fishpool.org/misc/mythtv-dvb-capture-fails-libmpeg2.mpg
you'll find a 40MB beginning of a DVB-T capture consisting primarily of
commercials with several aspect ratio changes between them. Transcoding
this file from MPEG2 to MPEG4 with mythtranscode will reliably screw it
up on my system. What's more, playback of the original only works with
certain configurations as well!

MythTV - Standard XvMC exhibits error blocks in parts of the recording,
and often crashes due to memory corruption.

MythTV - libmpeg2 changes to "green squiggly mess" at the beginning of
the program (a few minutes into the capture).

MythTV - Standard correctly plays it

"mplayer -vfm ffmpeg" will also play the file, while "mplayer -vfm
libmpeg2" exhibits the exactly same problem as MythTV and libmpeg2.
Videolan-client shows a completely different set of symptoms: it decodes
the entire stream correctly, but between recordings switches the aspect
ratio in places where neither MythTV nor MPlayer do, and does it to the
wrong direction, flattening the picture to half its intended height.

Using the lossless MPE2-MPEG2 transcode results in a slightly smaller
file that has the exact same demonstrable behavior in these programs.

//osma