sorry for my lame kick in, again. maybe i'm a dumbass but i feel some 'overcomplication' here. imho, u don't need anything else than the par value for making correct resizing.
the equation considered is :
dar = par x sar
where
dar : display aspect ratio (what ratio to be displayed)
sar : stream/sample aspect ratio (the original/non-cropped aspect ratio of the stream)
par : pixel aspect ratio
note, these all are given if your source can be played correctly !
actually, par is a multiplier giving how much the image must be expanded horizontally so as to get the correct/intended dar. that's what all players (should) do.
if the stream is cropped (whatever way !), the resulting dar value stays correct if the same par is used for resizing. of course, the picture will be higher or lower but not distorted.
it's quite easy to demonstrate. take your favourite dvd, make some different arbitrary but player compliant (say, mod16) cropping and than some short anamorphic encodes. (to go up to the studio logo is far enough for checking) set par value according to what shown on the dvd cover (can be 4:3 or 16:9only !). won't see any ratio distortion. (if someone would tell me how to upload images to doom9, i would show some demo pics, but it's worth to try personally
)
the bests
y
ps if i get wrong what u're talking about, pls, forgive me
