[whatwg] Change request: rules for pixel ratio

[Charles]

> Does this mean the implementation must retrieve the self-described
> pixel aspect ratio from the stream and supply it as part of the DOM?

Offhand, I can't think of any use cases where it'd be useful to expose pixel
aspect ratio.

(Before folks chime in, note that pixel aspect ratio <> picture aspect
ratio.  A typical video encoded for PC viewing would have a pixel aspect
ratio of 1:1 and a picture aspect ratio of 4:3 or 16:9.)

-- Charles