At work, I have been asked to demo PPI (Pixels Per Inch) value on different video profiles and its effect on the iPad.

Well what is the PPI and how do you calculate that? It was quite simple at the end


W=Width of the video
H=Height of the video
S=diagonal size of the screen
PPI = SQRT(W^2+H^2)/S


Why does this matter? When video becomes available to handhelds such as tablets, broadcasters want to ensure that these new devices are not becoming a substitute to traditional broadcasting experience on large panels at your home. Thus PPI limitations are enforced to ensure video’s available on tablets are not mirrored to your TV screens at home.