Hi.
1:
If I use ffdshow as audio decoder and microsoft dtv-dvd as video decoder Mediaportal freezes when I change channel from a mpeg2 to a mpeg4 channel (see logs). But if I start tv on a mpeg2 channel and then turn off tv then I can start a mpeg4 channel without problems..
If I choose microsoft dtv-dvd as video and audio decoder all works fine.
I would suggest you to use MS audio decoder (as it has been designed to work with live tv. MS uses it in MCE).
Germany