You don’t have to do the 1.33 one if you don’t want to.
It’s 576p not 540p.
storage resolution = 720x576
display resolution = 768x576. 768 divided by 576 = 1.33
A user on Myspleen said 576p has 20% higher resolution than 480p.
https://en.wikipedia.org/wiki/576p
Google - 720x576
Okay, yes 720x540 is 1.33 but PAL is 576p and what stated above is correct.