Get rid of @maxWidth and family

[sandersaares]

v4 section 3.2.4 has wording along these lines:

[...] the following attributes shall be present:
@MaxWidth (or @width if all Representations have the same width)

Plus similar for other "max" attributes.

These maxABC attributes seem to be a potential source of conflict and overall seem unnecessary. I have seen conflicting data in the real world and even created such content by accident!

I propose we remove the requirement and make an inverse recommendation: @maxWidth and family (all the other max) SHOULD NOT be present in an MPD. Clients are expected to calculate max values and SHALL NOT rely on @maxWidth and similar attributes.

This seems like a useful simplification to me.

PS. I looked at a few players and found zero usages of these "max" attributes. I think it is trivial for players to just iterate representations to find the max in any case.

PPS. The explanation about "target display size" in the same chapter seems rather dubious to me but if we get rid of these attributes we get rid of any potential misunderstanding there, too, so I guess not worth getting into this.

[haudiobe]

I agree that max is not a good idea. I believe we should change the MAX values to be used for intended display setup. This is proposed in CTA WAVE.