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Converting NTSC to PAL 16:9 Anamorphic

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Jim McMahon
Converting NTSC to PAL 16:9 Anamorphic
on Apr 27, 2009 at 10:44:55 pm

OK, this seems like a very basic question, but I searched for it and have had no luck so far. Here we go:

I am submitting a NTSC full-frame (4:3) spot to an awards show in France, and they are requiring that the spot be sent to them as a quicktime with the following specs:

•720 x 576 anamorphic 16:9 - D1 PAL 25 fps.

I double checked, and yes, they definitely want the clips anamorphically, so that they can just throw them all together, 16:9, 5:4 and 4:3, and play them all without any problems.

OK, fine, but I'm very confused as to how to get the best image quality out of this process. As far as I can tell, my best bet is to stretch&squeeze the footage to 480x576, and then add black bars to the left and right.

I came up with 480x576 in the following way:

•Stretched the entire clip while maintaining NTSC aspect ratio, from 720x480 to 854x576.
•Divided width (854px) by 1.78 (16:9), which equals 480px wide. This accounts for the 16x9 squeeze.
•Maintained 576px as final height.
•Final size is 480x854, but when unsqueezed on a 16:9 screen, the frame size will be 854x576.

Here's a big question:

Does the PAL TV have the same type of non-square pixels as NTSC TVs? The strategy I have to maintain my aspect ratio rests on my assumption that PAL pixels are the same ratio as NTSC pixels.

I feel that the above process is the best way to maintain my correct aspect ratio, assuming PAL TVs do have non-square (vertical) pixels.

When I simply resize the image to PAL WITHOUT maintaining my aspect ratio, it makes the images skinnier. What I'm most worried about is that, once this image is played on a PAL TV, the images will be EVEN SKINNIER, to a point of being absurd.

I tried resizing the image up to 720x576 while mantaining aspect ratio (crop), but then I'm losing the info on the sides. I'd rather that the image is a bit wider than normal to retain that info. After all, they ARE projecting it in 16x9, so that shouldn't matter.

Sorry for the long post. Thanks for the help!

Best,

Jim


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Dave LaRonde
Re: Converting NTSC to PAL 16:9 Anamorphic
on Apr 28, 2009 at 3:04:54 pm

Hey, if it works, it works.

It sounds like you have the frame rate conversion issues squared away -- it isn't exactly a piece of cake to convert 29.97 to 25 in AE: you might need third-party plugins or look for Andrew Kramer's Frame Rate convertor tutorial. Look for it on videocopilot.net.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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Asmund Voll Tesdal
Re: Converting NTSC to PAL 16:9 Anamorphic
on May 2, 2009 at 12:30:32 am

If I remember correctly, the aspect ratios of NTSC and PAL are not the same. I'm guessing they're pretty close (and yes, PAL is also non-square), so I don't know if you'll actually be able to see the difference.

[Jim McMahon] "•Divided width (854px) by 1.78 (16:9), which equals 480px wide. This accounts for the 16x9 squeeze."

Since the image is already 4:3, dividing by 1.78 is too much. If you have a PAL 4:3 image, dividing width by 1.33 (75%) should give a correct aspect for anamorphic.

Also, I didn't quite get what you mean here:

[Jim McMahon] "•Final size is 480x854, but when unsqueezed on a 16:9 screen, the frame size will be 854x576."

When you say final size, do you mean the frame size of the final video? Unless I'm completely missing something, that needs to be 720x576.


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