[mythtv] digging into the mplayer/mencoder problems with RTjpeg

[Aran Cox]

I started looking into my problems when playing back (or transcoding)
RTJPEG/nuv files created by MythTV with mplayer.  Basically, it seems
that mplayer/mencoder misinterprets the V/1 frames.  That is, the frames
with a frametype of V (video data) and a comptype of 1 (RTJpeg) cause
mplayer to show the dread green blotches.  

The majority of the video frames created by MythTV on my system have a
comptype of 2, RTJpeg with lzo afterward.  However, every now and then a
small cluster of comptype 1 frames appear and so does the corruption.

Now, the question is how do I get mplayer to interpret these frames
correctly.  It seems that the RTJpeg code in MythTV shares an origin
with the mplayer code, and I think somthing in RTjpenN.{c,cpp} is
probably to blame for the fact that MythTV can shows these files and
mplayer cannot (correctly at least.)  

Frankly I'm a little bewildered at the RTJpegN code... so could someone
possibly confirm that I'm on the right track here?  

Can someone tell me why MythTV uses V/1 occasionally and V/2 most of the
time?  

Cheers,
Aran