RTCRtpSender: setParameters() et al missing scalabilityMode param option

[hamishwillee]

What type of issue is this?

Missing compatibility data

What information was incorrect, unhelpful, or incomplete?

There are some extensions for SVC in WebRTC in https://w3c.github.io/webrtc-svc/ - these were implemented in Chrome in 111 as per
https://chromestatus.com/feature/5769626174619648

The change appears to be an addition to the dictionary RTCRtpEncodingParameters of scalabilityMode

partial dictionary RTCRtpEncodingParameters {
             DOMString scalabilityMode;
};;

RTCRtpEncodingParameters is used in several places including

• https://developer.mozilla.org/en-US/docs/Web/API/RTCRtpSender/setParameters
• https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection/addTransceiver#sendencodings

Param needs to be updated in those

What browsers does this problem apply to, if applicable?

No response

What did you expect to see?

Subfeatures.

Did you test this? If so, how?

By inspection, but you can also test using https://wpt.live/webrtc-svc/RTCRtpParameters-scalability.html

Can you link to any release notes, bugs, pull requests, or MDN pages related to this?

mdn/content#37722 (we report the stats, just don't allow them to be set in this way)

Do you have anything more you want to share?

No response

MDN URL

No response

MDN metadata

No response