Although I don't yet have a Blu-Ray burner, I've been experimenting a little bit with creating Blu-Ray images and folders from Encore CS3, and testing those out a bit with.

I'm working with a project that contains 1920x800 content, which I render to 1920x1080 without stretching the video at all. What I'm wondering though is why, when I choose to render as MPEG-2 using the "Blu-Ray 1920x1080-24p, 25mbps" default profile, is the aspect ratio set to 16x9 Display?

I'd always assumed this setting controlled the pixel aspect ratio of the rendered video, and that setting resulted in the 1.2 PAR used for anamorphic DVD content. However, I thought 1920x1080 Blu-Ray content is square-pixel.

I tried rendering the same project twice using both settings, and ironically the one rendered as the 16x9 setting displayed properly in PowerDVD, while the square pixel render was distorted and pillar-boxed. Encore also refused to recognize the latter as widescreen (it was 4x3, and the selection area was grayed-out, so I couldn't change it), whereas it behaved properly with the former.

So, what's going on with this? Is the function of the Aspect Ratio in Vegas' render settings changed when working with 1920x1080 to some kind of flag that tells the player to go widescreen or fullscreen?