From 5:4 to 4:3

[humanoid86]

If input and output PAR differ, Hybrid will adjust the height/width to maintain the same display aspect ratio while taking the changed pixel and storage aspect ratio into account.

Ok, but why the input resolution is 720x576 ( Hybrid detect 1:1 anspect ratio)  and if i change the input par to 16x15 , the output is again 720x576? there is a resize to the same size? i can add the PAR values on a 2nd time after rendering? (are these values just something hardcoded on the CLIP to make players able to understand what "kind" of pixels geometry is used?)

mi question is: if i leave unchanged the PAR / DAR (these will be copied from original)... that are from a VHS (recognized as 5:4) .. anyone watching the video is seeing not circles but vertical ellipses (because the original footage are for OLD CRT with rectangular pixels) .. i want to be sure that who is watching the clip can see' circles on car wheels .. maybe i need to leave PAR /DAR  original and resize to 768 using modern algorith to obtain a 768x576 final video that can be played on TV - PCplayers - video editors without any horizontal strecthing issue?

try it - x264 < quantizer

PS
DAR/PAR is in the codec