[mythtv-users] Re:Transcoding advice (long)

[Chris Petersen]

> Tried to use nuvextract

It's "nuvexport"

> Tried adding the --fifosync (or is it --syncfifo?) option to the
> mythtranscode command line. It seems to hang after transcoding a small
> portion. I expect the --fifosync option is not valid.

This has NOTHING to do with av sync..  like the paramater says, it's a
fifo sync.  You *need* to enable this if you have two programs accessing
the fifos, or mythtranscode will buffer the audio/video streams as each
fifo gets read - the audio usually encodes a LOT faster, which leaves
you with a HUGE video buffer (600+ megs depending on encode speeds and
how long your recording is).  However, when you enable fifosync,
mythtranscode sends data slowly to the fifos, and won't write more until
each has "emptied out".  If you only have one program reading the fifos,
it will appear to hang because both it will be waiting for data on one
fifo while mythtranscode is waiting for the program to finish reading
data from the other fifo.

I wish I could offer advice or help about transcoding, but since I only
have a bttv card, I don't have much to test with.  AV sync issues plague
all encoding, though - it's just a matter of finding the right
parameters for the encoders (though it's weird since mythtranscode sends
the same kind of raw data with mpeg-based nuv files that it does with
rtjpeg/mpeg4 ones).

-Chris