1121154 - [EME] Refuse to load GMPs with unsupported APIs in their .info file

Status: RESOLVED INVALID

(Core :: Audio/Video, defect)

Description

[Chris Pearce [:cpearce (Not reading bugmail)]]

If a GMP has an API name in its .info file that gecko doesn't support, we should refuse to load it.

This way, if the CDM is for a newer (or older) version of gecko, we won't expose it as usable to JavaScript, even though it isn't actually usable.

Comment 1

[Chris Pearce [:cpearce (Not reading bugmail)]]

Maybe we should even go as far as deleting the GMP if it supports APIs Gecko doesn't support?

Comment 2

[JW Wang [:jwwang] [:jw_wang]]

I don't quite understand the problem here. Can you give an example?

Take Navigator.requestMediaKeySystemAccess as an example, our code flow will be:
   
   MediaKeySystemAccess::IsKeySystemSupported("org.w3.clearkey")
=> HaveGMPFor(mps, "org.w3.clearkey", "eme-decrypt-v3")

If the plugin's .info file says "eme-decrypt-v2", HaveGMPFor() will return false and reject the promise and the CDM won't be usable to the script.

Comment 3

[Chris Pearce [:cpearce (Not reading bugmail)]]

You're right, thanks to our HaveGMPFor checks we won't load a GMP which is out-of-date. I had forgotten about this. Thanks for checking this!

Comment 4

[Chris Pearce [:cpearce (Not reading bugmail)]]

Mass update firefox-status to track EME uplift.