4:3 PAL source will look vertically stretched on a 1:1 PC screen, scaling it to 720x488 will look even more stretched on a PC screen but on a 16:9 screen it will look correct (with the borders making it 720x576).

I've ripped a few scenes of different PAL anamorphic widescreen 2.35:1 movies (including star wars the phantom menace and gangs of new york) and opened the m2v files in virtualdub mod. The black bars are between 69 and 73 pixels leaving between 430 and 438 pixels for the movie. So 488 is too much.

It would've helped if you supplied the correct numbers in the first place

693x324 PAL letterboxed when scaled to PAL anamorphic 720 width is 720x448, not 720x488

For creating anamorphic PAL footage from letterboxed PAL footage I've done a few calculations.

I'd like to try some things out, but have just gotten started with avisynth. Can someone give me an example for a script to do this? Thanks a lot.

Try:

crop(0, 126, 720, 324)
Lanczos4Resize(720,432)
addborders(0, 72, 0, 72)

Alright thanks. That exactly what came out of my calculation btw:

720/4*3=540
720/16*9/540*576=432

I can't make sense of your calculation; what you've basically done is 576/(4/3). Now if you used 576 because it's the total number of lines in the PAL image, then the method is incorrect. However, the answer is right because, by coincidence, 576 is also equal to the number of active lines in the letterboxed picture 324 * (16/9).

My result was based on 324 * (16/9) / (4/3) = 432.

This was my train of thought. The original image is 720*576, at a 4:3 aspect ratio. You want to go to a 16:9 aspect ratio of 720*x. If the pixel ratio would match the aspect ratio you would expect it to be as easy as this: 720/16*9=405. But they don't match: 720/4*3 is not 576, but 540. So to go from the aspect ratio to the pixel ratio you'd have to multiply it by 576/540. If you apply that to the 405 you got from the previous calculation you get 432. So there's that. But where did you get your 324 from?

I see what you've done now, you've calculated how to turn a 16:9 anamorpic image into a 4:3 letterboxed image - compress 576 lines down to 432 and add 72-line thick bars top and bottom.

That's not what we're doing here. The image starts off in 4:3 and we want to make it 16:9. To do that it must be stretched vertically by (16/9)/(4/3)=1.333.

After cropping out the black bars with crop(0, 126, 720, 324) we have 324 lines left.

324 * 1.333 = 432.

I just noticed we were doing the same thing, only I was creating an anamorphic image, original black bars included. Which is something you don't want to do, I know now. 324*1.33=432 and 432*1.33=576 you see? We were just thinking in different directions.

I don't apply the same script on the whole movie btw, because of the vertical shifts. My DVD versions don't have them.