If you can guys, try and calculate "everything" as a fraction, because converting fractions to decimals and back to fractions again "can" produce conflicting Aspect Ratio Signalling (ARS) values.
If your NTSC movie has an aspect ratio of 1.33:1, then this can be represented as a fraction of 4/3. Meaning: -
Code:
4 480 1920 8
- x --- = ---- lowest dominator - Giving an ARS value of 8:9
3 720 2160 9
If your NTSC movie has an aspect ratio of 1.77:1, then this can be represented as a fraction of 16/9. Meaning: -
Code:
16 480 7680 32
-- x --- = ---- lowest dominator -- Giving an ARS value of 32:27
9 720 6480 27
If your NTSC movie has an aspect ratio of 1.85:1, then this can be represented as a fraction of 37/20. Meaning: -
Code:
37 480 17760 37
-- x --- = ----- lowest dominator -- Giving an ARS value of 37:30
20 720 14400 30
If your NTSC movie has an aspect ratio of 2.35:1, then this can be represented as a fraction of 47/20. Meaning: -
Code:
47 480 22560 47
-- x --- = ----- lowest dominator -- Giving an ARS value of 47:30
20 720 14400 30
If your NTSC movie has an aspect ratio of 2.40:1, then this can be represented as a fraction of 12/5. Meaning: -
Code:
12 480 5760 8
-- x --- = ---- lowest dominator - Giving an ARS value of 8:5
5 720 3600 5
For working out the "Aspect Ratio Signalling" values of PAL sources, simply substitute 480/720 to 576/720 and recalculate.
The same formula can be used to work out the "Aspect Ratio Signalling" values of cropped and re-sized encodes too by entering the relevant resolutions.
Cheers