Re: [mediacapture-image] Clarify meaning of PTZ constraints presence (#256)

> But that is just a note. If that meaning is to be retained, it should be spelled out in the main descriptions and not only in a note.

Agree. Normative statements should never reside solely in notes. Notes clarify normative text or algorithms elsewhere, and  should never directly contradict algorithms.

Here I see spec support for the permission part only, not _"capability request"_ which appears undefined.

> Having to deal with a range that is the union of all floating point numbers, true and false, where true and false have specific meanings that are not translations to a floating-point range is probably going to be harder in terms of implementation 

Implementers come last in the [priority of constituencies](https://www.w3.org/TR/html-design-principles/#priority-of-constituencies). I think we must prioritize preserving web compatible semantics for users (who come first).

> Let's take { video : { pan : 10, width : 1920 } } as an example with a 720p PTZ camera and a 1080p non PTZ camera.
> Which camera will be used? Say PTZ camera current pan value is 3600? or current pan value is 0?

This is a perfect example of why we defined the constraints algorithm in the first place.

What matters is not that I can intuit every corner case, but that it works the same in all browsers. Predictability trumps usefulness at the edges.

The only way to preserve web compatible semantics here is to strictly adhere to an algorithm. I think evidence of poor web compat points to browsers _not_ following the algorithm. 



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Received on Wednesday, 9 September 2020 13:56:12 UTC