[mythtv] A/V sync problems (bug?)

[Torbjörn Jansson]

I have a epia m10k that i use as a frontend.
I use mythtv 0.15.1 and not cvs (yet)

On some recordings i have some wierd a/v sync problems, for example if
someone talks first i see them saying something, then i hear the sound.
The compression settings is the same for both working and non working
recordings, mpeg4 640x480 and mp3 audio.

I have turned on the experimenta av sync setting and jitter reduction.
If i turn off experimental av sync and jitter reduction, the picture first
playse fast for a few seconds and then it plays slow and then fast again.
Another thing that coud happen is that the audio gets choppy, like it has
some tiny pauses.


One thing all problematic files have in common is that the audio timestamps
on the first few audio samples is some realy large negative value, like
this:

A problematic file:
Orginal AudioTimeStamp: -2026130406
Orginal AudioTimeStamp: -15
Orginal AudioTimeStamp: 9
Orginal AudioTimeStamp: 32
Orginal AudioTimeStamp: 78

Antother problematic file:
Orginal AudioTimeStamp: -1161189719
Orginal AudioTimeStamp: -1161189696
Orginal AudioTimeStamp: -1161189672
Orginal AudioTimeStamp: -18
Orginal AudioTimeStamp: 1
Orginal AudioTimeStamp: 48

A working file:
Orginal AudioTimeStamp: -8
Orginal AudioTimeStamp: 11
Orginal AudioTimeStamp: 34
Orginal AudioTimeStamp: 57
Orginal AudioTimeStamp: 80

As you can see the first few audio samples is realy weird.
I don't know if this is the cause of the problems or not, but it's the only
common thing I can find.
The keyfram and filters field in rtframeheader didn't look right on the
samples with weird timestamp.
Maybe the rtframeheader struct isn't initialized properly?