add support for aspectRatio constraint in videoResolution

[lukasIO]

No description provided.

[davidzhao]

Is this needed when both width and height are required? What is the use case?

[lukasIO]

setting aspectRatio explicitly can have an influence on the order/importance of applied constraints.
An example would be

const constraints = {
  width: { max: 1280 },
  height: { max: 720 },
  aspectRatio: { exact: 1.5 }
} 

in order to get any video smaller than 1280x720 that has a 1.5 aspect ratio.

Side note: apparently constraints are applied in order, if all of them are set as a plain number/value instead of specifing min/max/exact.

The prioritization of the properties is simple: if two properties' requested values are mutually exclusive, then the one listed first in the constraint set will be used.
https://developer.mozilla.org/en-US/docs/Web/API/Media_Streams_API/Constraints#requesting_a_specific_value_for_a_setting

So setting

const constraints = {
  width: 1280,
  height:  720,
  aspectRatio: 1.5
} 

would potentially have a different result than

const constraints = {
  aspectRatio: 1.5,
  width: 1280,
  height:  720
} 

[davidzhao]

ah interesting.. that makes sense.. lg.