Thanks to Markus’ help I’ve manage to get 480px2 working on the VP50 Pro. Here’s the settings you need to use.
*Adjust H.backporch as necessary to centre the image.
With these settings I get an image that’s quite badly squashed on the vertical, but by using the vertical zoom control on the VP50 this can mostly be corrected. This does mean the scaling is not pixel perfect. 480p scanlines don’t look too good, but I dug out my SLG3000 and paired it with my Dreamcast and, 240p scanlines as added by something like a SLG3000 look great. The checkerboard test (as featured in my early screenshot with the DVDO Edge) looks perfectly acceptable.
This is Zero Gunner on the Dreamcast using 480pX2 mode, Allow Upsample 2x on. No softening done by the VP50 Pro.
When I used 480p X2 mode before I pretty much dismissed it as not for me. The over-sharp sawtooth edges were just too much and not to my taste, but honestly it looks really great here (the iPhone camera doesn’t do it justice).
I’m definitely a 480p X2 convert, I need to get my Edge down from the loft and see how that looks too.