Though I didn't investigate it much, is it possible to use the software setting and tell it to get it from the DVD player software? This seems it would be the optimal config, right?

This is the whole point of Total Recorder. The idea is that it's a driver layer between the application and the sound card.

The application sends digital data bytes to the sound card. The Total Recorder driver pretends to be a sound card, intercepts those digital data bytes, and sends them to the hard disk before passing them on to the real sound card.

If you can't configure Total Recorder this way, then there's not really much point in using it. At that point, you might as well just plug a consumer DVD player into the line-in jack on the sound card because you won't get much benefit going the analog route.

So yeah, you should check its online help and make sure it's Doing The Right Thing.