SAR for 544x576 4:3?

[kodec]

What would be SAR for a 544x576 4:3 PAL source?

[poisondeathray]

For 4:3 Exactly, it would be 24/17

4/3 = 544/576 * 24/17

[kodec]

Thanks posion. How do you do that? I got somehow to 1.411 which is the same but had no idea how to make 1.411 look like 24/17. Searched for an online converter for such but couldn't find any.

Now I would need another SAR, for a 480x576 4:3?

[jagabo]

Universal relationship:

DAR = FAR * SAR

DAR = Display aspect ratio, the final shape of the picture
FAR = Frame Aspect Ratio, frame_width:frame_height
SAR = Sampling Aspect Ratio, relative distance between pixels horizontal:vertical

algebraic rearrangement gets:

DAR / FAR = SAR

Numeric substitution gives:

4/3 / (480/576) = SAR
4/3 * 576/480 = SAR
2304 / 1440 = SAR
(divide both by 32 gives)
72 / 45
(divide both by 9 gives)
8 / 5 = SAR
8:5 = SAR

Or starting at 2304 / 1440 = SAR, calculate all the prime factors calculator yourself, or use a calculator:
https://www.calculatorsoup.com/calculators/math/prime-factors.php

2304 / 1440 = SAR
(2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 3 x 3) / (2 x 2 x 2 x 2 x 2 x 3 x 3 x 5) = SAR
(remove common values)
(                    2 x 2 x 2        ) / (                            5) = SAR
                     8                  /                              5  = SAR
8:5 = SAR

[somespirit]

Thanks posion. How do you do that? I got somehow to 1.411 which is the same but had no idea how to make 1.411 look like 24/17. Searched for an online converter for such but couldn't find any.

Now I would need another SAR, for a 480x576 4:3?

we have 480x576 4:3 resolution, so first we do 576x1.3333333(4:3)= 768, this means our real resolution is 768x576, then final operation is to compare (divide) two resolutions 768x576 and 480x576 ---> 768/480 = 1.6 (16/10) --> SAR is 16/10 or 8/5 (both will work)