how is addTrack without a stream signalled in the sdp?

[fippo]

from here in the infamous #1128 issue:
addTrack allows adding a track without a stream

How is this signaled in the SDP? https://tools.ietf.org/html/draft-ietf-mmusic-msid-16#section-2 doesn't allow an empty msid-id

The pragmatic solution is probably to generate a random stream id. This also means that ontrack always has event.streams with a length > 0.

In the steps to create addTrack this would need to be handled here:

Let streams be a list of MediaStream objects constructed from the method's remaining arguments, or an empty list if the method was called with a single argument.

[fippo]

cc @henbos @jan-ivar

[jan-ivar]

I'll reiterate the idea I mentioned in here:

If we used the same random id for both the stream and the track in this case, then the remote browser could omit creating a stream in this case.

Unless we care about this edge-case in non-browser end-points, we might not even need to involve ietf. Unless there's something in ietf that says stream ids and track ids are in the same namespace?

[taylor-b]

"-" is used in the "a=msid" to represent "no stream". So I don't think this is an issue. This was a change from version 15 to 16, and is described in section 3.