Pixel Aspect Ratios

[Arval]

Ok here's the question:

I have seen that the pixel aspect ratio used in PAL DV is 1:1.067.

That said, what distortion of the image can I expect (if any) when converting an avi or other computer-based video format that is in the VGA aspect ration, 1:1. Will my people be 6.7% fatter?

It's niggling at me that some of the DVD's I have authored may not quite have the correct aspect to them. What makes me suspicious is that TMPGEnc tells me that the input file is '1:1 VGA' and the output file is '4:3 Display.'

It doesn't say whether the 1:1.067 pixel aspect ratio difference is automatically corrected.

Can anyone clear this up for me?

Thanks

[Specialist]

Some articles that you might find helpful:

http://www.creativecow.net/articles/gerard_rick/pixel_madness/

http://www.kenstone.net/fcp_homepage/basic_ps.html

Ben Waggoner also wrote an article for DV MAGAZINE.

His entire article can be read on DV.com.

Here are some good excerpts:

"The good resolution numbers for good square-pixel graphic sources are 768 x 576 pixels for 4:3 projects and 1024 x 576 pixels for 16:9 projects."

"Of course, these numbers work for 486-line NTSC as well as PAL projects, but strictly speaking can lead to a 1 percent vertical squash for NTSC DV with its 480 -line frame, if the image is brought into a 720 x 480 comp."

"For 720 x 480 comps and timelines, a 720 x 533 pixel source is more correct (Adobe uses 720 x 534 in its Photoshop preset, which is close enough)."

The default menu templates in Ulead DVD WORKSHOP 2.0 feature the 768 x 576 frame size.

Hope this helps,

Jerry Jones
http://www.jonesgroup.net