[mediacapture-main] Pull Request: Clarify what happens to non-applicable constraints.

henbos has just submitted a new pull request for https://github.com/w3c/mediacapture-main:

== Clarify what happens to non-applicable constraints. ==
Fixes #533.

Some of the constrainable properties are said to be "defined to apply only to [video/audio] MediaStreamTrack objects". It is not clear whether specifying a constraint that doesn't apply for the type (e.g. {audio:{exact:640}}) would cause an OverconstrainedError or simply be ignored. Both are valid interpretations.

This PR says to ignore such constraints, because...
- This is what current implementations do.
- This requires less code to be updated when new constraints are added.
- If a constraint is not recognized by a User Agent it is ignored (because constraints are passed as dictionaries, anything not in the IDL would be ignored); this is consistent with "constraint is not implemented for this type".
- This would allow editorial changes such as splitting audio and video constrainable properties into separate dictionaries without implicitly causing change in behavior.

See https://github.com/w3c/mediacapture-main/pull/542

Received on Wednesday, 3 October 2018 15:35:27 UTC