[Cin] SAR, DAR, PAR - oh, my!

[Andrea paz]

I don't quite understand how ffmpeg considers the various aspect
ratios. However from the site lurkertech you pointed to (and from
which I had taken some definitions put in the manual) PAR and SAR are
not the same thing: PAR is about pixel shape and size; SAR is about
frame shape and size.

To change the manual I would like to be sure that ffmpeg really
considers PAR=SAR.