[ortc] If multiple encodings are given, ssrcs are needed

ibc has just created a new issue for https://github.com/openpeer/ortc:

== If multiple encodings are given, ssrcs are needed ==
Once capabilities are negotiated and so on, a browser sends the 
following to a SFU (simulcast with two audio encodings using different
 codecs):

```js
rtpSender.send({
        codecs : [
                {
                        name        : 'audio/opus',
                        payloadType : 101
                },
                {
                        name        : 'audio/pcma',
                        payloadType : 102
                },
                {
                        name        : 'audio/CN',
                        payloadType : 96
                }
        ],
        encodings : [
                {
                        codecPayloadType : 101
                },
                {
                        codecPayloadType : 102
                }
        ]
});
```

Note that SSRCs are not signaled.

Then, the first packet the browser sends is a CN with ssrc '12345678'.
 How does the receiver (the SFU) know which encoding it belongs to?

This applies to other use cases (different encodings with same 
`codecPayloadType` and unset `ssrc`, etc).

Please view or discuss this issue at 
https://github.com/openpeer/ortc/issues/568 using your GitHub account

Received on Monday, 20 June 2016 10:18:02 UTC