Question: can plex use wtv files?
Answer: While Plex "may" be able to play and transcode your WTV files, it will have to do heavy transcode of the MPEG2 format into h264 format on-the-fly. If you have a really powerful Plex server, this can work, but it will still eat your CPU. You're better of transcoding first, before trying to play them through Plex.