TMPGEnc MPEG Editor 3 from Pegasys Inc. now has wtv input support with their latest software revision (ver. 3.1.2.108). The MPEG editing software allows users to import their wtv files, edit them with frame-level accuracy, and output them in MPEG video, DVD, DVD-VR, or Blu-ray (BDAV) formats (input format must be compliant with output formats).

Apparently, only MPEG-2 wtv files are supported (makes sense since this program only supports MPEG sources). Includes burning capability for DVD-Video, DVD-VR and Blu-ray (BDAV). When outputting to DVD-Video, you can include a simple DVD menu for easy viewing. Smart rendering feature will only re-encode sections that are edited, leaving video quality intact with no degradation.

Update is free for current users. Free trial available for new users and prices start at $39.95.

Product webpage:
http://tmpgenc.pegasys-inc.com/en/product/tme3.html