Scalable Video Coding example needs update

[opusonline]

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Browser affected

Browser name including version (e.g. Chrome 64.0.3282.119)
no specific version, but I have tested it with Chrome 111.0.5563.64

Description

Thank you for having the Scalable Video Codec sample, but unfortunately it relies on using an outdated and non-working feature, so the sample can't be used.

https://github.com/webrtc/samples/blob/gh-pages/src/content/extensions/svc/js/main.js#L108

The sample uses the SVC extension of .getCapabilities(), but this has been removed. It should be replaced with the current working method navigator.mediaCapabilities.encodingInfo with video scalabilityMode parameter.

Here's the discussion about "getCapabilities() vs. MediaCapabilities":

• SVC getCapabilities() is redundant with Media Capabilities query w3c/webrtc-svc#49
• Remove extension to getCapabilities() in favour of MediaCapabilities w3c/webrtc-svc#76

Steps to reproduce

Open https://webrtc.github.io/samples/src/content/extensions/svc/ in any browser that supports SVC (currently Chrome since v111, see https://chromestatus.com/feature/5769626174619648) and select any codec that should support scalability modes, like VP9 or AV1.

Expected results

The "Scalability Mode" dropdown should act accordingly and contain supported scalability modes for each selected codec.

Actual results

The "Scalability Mode" dropdown will always stay disabled and only contain the option "NONE".

[alvestrand]

Florent, can you take on the task to update this?

[alvestrand]

the fix shoujld be a fine example of how to use MediaCapabilities to work around the lack of an enumeration feature.

[Orphis]

Fixed by #1595.