[mythtv] DVB corruption for 5 seconds when recording

[Brian May]

Hello,

Two DVB shows I recorded had extreme picture+sound corruption for the
first 5 to 10 seconds.

One of these shows, the corruption was too much for the frontend and
it repeatedly crashed while trying to play it. This rendered the
entire show unviewable. The show was still being recorded at the time.

Today, when trying to play the same video, all I get is extreme
corruption, but no crashes. Arrghh! I had gdb all set up to catch
it...

Stepping through the frames one at a time, I get a "good" (or at least
better) frame every now and again, followed by a number of 15-20 bad
frames. At first I thought it might be I frames that are OK, but I am
not entirely convinced with this theory.

By extreme curruption, I mean extreme blocking artifacts. By "good"
frames, I mean frames that have no blocking artifacts. The top half of
this frames is perfect, the bottom half seems to be the last row of
pixels repeated down the screen, ie. almost looks like a water
reflection. I don't think this scene was suppose to have this
effect...

Any ideas on:

1. What is causing this extreme curruption? As far as I can tell, it
   doesn't appear to be reception problems, as it only occurs at the
   start of shows.

2. What is causing the frontend to crash when watching these shows,
   but only when running it via gdb is inconvenient?
-- 
Brian May <bam at snoopy.apana.org.au>