Actually it is possible to use AccessDTV and DScaler at the same time, but independantly, if you have enough CPU power. For example, sometimes I start timeshifting an HD show with AccessDTV but pause it so I can start watching late and skip commercials. Meanwhile I'll run DScaler and watch some other TV program coming thru a regular capture card from my TiVo. You would need to disable the overlay in AccessDTV (called "application video") to do this.
AccessDTV won't care what your desktop resolution is. It uses a separate output at the user selected HD resolution (when in fullscreen mode). For fullscreen viewing with AccessDTV you can choose between 480p, 720p, 1080i, and a couple other modes meant for computer monitors. The program will be scaled to the selected resolution by the AccessDTV hardware (or not scaled if it's the same).
- Dave