Aspect ratio confusion

[Mikael]

This might just be a terrible misunderstanding on my part, but I have serious aspect ratio problems with burning my PAL DV files to DVD. The programs I use (Ulead MovieFactory and Sonic Soundry) give you the option of a ratio of 720x576, which, as far as I can see, is considered the same as 4:3. But 4:3 would be 720x540! And the image gets to "high" on my TV when played on my standalone. And it seems impossible to modify the aspect ratio manually in the programs.

Please make this a bit clearer for me!

[--juggernaut--]

I don't have any experience with the software you mentioned, but you might try reading DJRumpy's guide on aspect ratios...very informative.

https://www.videohelp.com/forum/userguides/174200.php

[House de Kris]

Yes, DJRumpy's guide is quite nice and deserves a read. But to address your specific question, you are assuming square pixels as in computer displays. Video almost always uses rectangular pixels which makes your simple math go out the window. Recall that not only is 720x576 considered 4:3, so is 720x480 for NTSC. And 480x576 is 4:3 on an SVCD, with numbers like that you wouldn't think that it should be wider than it is tall, but it is. Remember, rectangular pixels.

[DJRumpy]

Remeber that full D1 resolutions (720x576, 720x480) can also have a 16:9 MPEG aspect ratio. PAL vertical Pixels are 1.2 times higher than NTSC pixels (their taller), which is why the ratio doesn't look right when you did the math.