I recently installed my PVR-350. I was going to go IVTV with a linux install, but yielded to Windows for my wife and her photography software.

Anyway, I've been really floored by cygwin and got most of what I need from it. I got it working last night, and I'll update this post as I get it more refined. To get this to work, install cygwin and the dvdauthor gui's on this forum. They give you the binaries mentioned in the script. I had to recomple mplex though... I'll see if I can't fix that. The cool thing about this it goes strait from mpg to vob without having to carve another 4 gigs out for each step.

==convert.cmd==
@echo off
bash convert.sh %*
============

==convert.sh==
#!/bin/bash
file=$1
mkfifo audio video mpeg
echo Starting audio with a delay to buffer fifo
mpeg2desc -a0 < $file > audio &
sleep 3
echo Starting video with a delay to buffer fifo
mpeg2desc -v0 < $file > video &
sleep 3
echo Starting mux to add NAV points to mpeg stream.
mplex -f 8 -o mpeg audio video &
sleep 3
echo Starting dvdauthor to write the fifos back to disk in VOB format
dvdauthor -o dvd_dir mpeg
rm $file
dvdauthor -T dvd_dir
echo All done!
============

To burn...
1) get the size by using 'mkisofs -print-size dvd_dir'
mkisofs -dvd-video dvd_dir | cdrecord-prodvd -dao dev=0,0,0 tsize=${size}s
rm -rf dvd_dir

Now if you want the mpeg back to make a compilation DVD (assuming your dvd is d: )
cat d:\\VIDEO_TS\\*.VOB > original.mpeg

The use of fifo's from a cygwin bash shell will also allow you to use this method with dvdauthor xml files. You just name the fifo as a file= in the xml.