RTCRtpReceiver.getParameters() needed

[ibc]

Related to #355:

Yes, to stop sending an encoding, call send() with parameters.encodings[j].active set to "false". Setting active to "true" and calling send() again will start sending again.
In WebRTC 1.0, getParameters() is used to retrieve RTCRtpParameters, and then setParameters() can be used with active set to "false" or "true" to accomplish the same thing.

If ORTC does not provide such a getParameters() method, then switching from active:true to active:false and vice-versa becomes very hard given that the user/app should keep the rtp parameters object previously passed to receive() in order to switch the active flag.

[robin-raymond]

Why do we need? is supposed to be identical to what was specified in the send so it would just return what was sent in previously... the danger in adding is the expectation that parameters start getting filled in, like RTP SSRCs, etc... and gathering that would make things async potentially. Unless it just returns what we passed in and then I question its value...

[ibc]

In short: IMHO we need a way to enable/disable receiving media in the track. Maybe a setter rtpReceiver.active = boolean.

[robin-raymond]

Change flag in parameters encodings local copy, call send() again with updated structure... ? this is more a way to keep the encodings stable so objects don't get created destroyed while being able to turn on / off a particular encoding.

[ibc]

That requires that the user holds the rtpParameters forever somewhere with no reason other than changing a subfield and passing again the entire object to receive() or start(). There is no other reason to keep such a complex rtpParameters object.

That's why a single active setter in both RTCRtpSender and RTCRtpReceiver objects makes sense IMHO.

[ibc]

To be more clear: I wouldn't like that my JavaScript ORTC client implementation needs to hold datas such as:

this.rtpReceiversStuff = {
  receiver1: {
    rtpReceiver   : INSTANCE_OF_RTCRtpReceiver,
    rtpParameters : object
  },
  receiver2: {
     [...]
  }
};

[ibc]

While I may agree with the negative to rtpReceiver.getParameters(), don't you agree that we deserve a simpler way for enabling/disabling a RTCRtpSender/RTCRtpReceiver without having to provide the entire RTCRtpParameters again? I mean:

rtpSender.pause();
rtpSender.resume();