I have tested out some 15 different converstion packages to convert the ReplayTV MPEG2 to an AVI format to view shows on the IRiver PMP. The only one I found that worked and was extremely easy to use is the DR DivX (
http://www.divx.com/) at $49.99. This has the option to preform batch conversion. I have found that the "Choose Personal Setting" of "TheKid's ReplayTV Encoding" is exceptional, with a resolution of 640 x 352 and DivX video of 1000 kbps average Bitrate. The certified DivX Protable video selection was pretty poor as the audio and video didn't match very well, and the video was incrediblly poor with the conversion. It cuts the size of the MPEG file down to about 1/2 in the AVI format. It does take quite a while to convert.
I use DVArchive to download the files off of the ReplayTV, which can be found at
www.dbarchive.org for free.
Hope you find this helpful.
Bill