MediaKeyStatus "internal-error" raised on platform only supporting up to 7 concurrent PlayReady contexts

[ArktekniK]

On some embedded platforms, there are resource constraints on the number of simultaneous playready contexts that can be created at the same time. For streams that make use of multiple keys, hitting this limit will cause an error.

There are some ways to signal the error it seems.

• Throw an exception during the call to MediaKeys.createSession (Current EME spec, not handled by dashjs)
• Via onkeystatuseschange with a MediaKeyStatus error of "internal-error". See EME Spec
• Via the MediaKeySession.close() call, which returns a Promise with (DRAFT update to spec) MediaKeySessionClosedReason of "resource-evicted"

I'm trying to understand how Dash.js handles this case, but I can't see any reference to the "internal-error" or "resource-evicted" string within the sources. My expectation would be that the player would back off of attempting to create more MediaKeySessions and/or manually close ones not being actively used to decrypt the current representations.

Does dash.js handle this case? If so, what's the behaviour?
Is raising an "internal-error" event the expected way for the user agent to handle this, or is another mechanism expected?

Thanks

[ArktekniK]

It seems that #4238 and #4239 might be related in that any MediaKeySession deemed not "usable" is closed (Including those with a status of "internal-error"). Although because the MediaKeySessionClosedReason is not part of the final spec yet, there's no way to handle resource limitations?