Re: [maitai] Roles of Sender and Receiver

["Duckworth, Mark" <[e-mail]>]

Peter,

That is a very good question.  I think we don't have an easy answer yet, it needs some discussion.  The issue gets a bit more complicated for multipoint, when there could be an MCU in the middle that is also part of the decision process.

>Consider a three display, 3 camera (3d3c) room A sending to a 1d1c room B.
>Does A offer all three streams to B and let B pick?

That is certainly a good possibility.  If B can choose dynamically, changing the choice during the session, it is similar to the current standard ability for B to select a video source from A using the H.281 SELECT VIDEO SOURCE message.  But the list of possible sources supported in H.281 isn't good enough for this application.

Maybe B wants to receive something like "current speaker stream" or "presenter stream", no matter which of A's three cameras it comes from.  I think of this as B making a higher level choice, and delegating the specific choice to A.

Maybe A is capable of sending a single stream that includes all the people in the room (perhaps by zooming out a camera, or combining three camera images into a single stream).  B might prefer to receive that type of stream.

I tend to agree an approach that gives B some control is more powerful and useful.  But I also think there are use cases where we want everything to be automatic, so we should not require a human user at site B to do anything in order to receive useful streams.

Mark Duckworth

-----Original Message-----
I have been pondering possible ways of representing a room configuration - but I think I need to back up and ask a question about basic interop architecture. 

In the selection of content on a stream, who is the active decision making entity, sender - or receiver - or both?

Consider a three display, 3 camera (3d3c) room A sending to a 1d1c room B. 

Does A offer all three streams to B and let B pick? (This leads in the direction of dynamic changes based on B, which is powerful but leads us into continuous control...)
Does A determine B has only one display and select which video B should get and send only one stream?

IHMO an approach which lets B have control over what it gets is more powerful. e.g. If I have heard the pitch from the speaker 100 times, I want to watch the customer and see if they are engaged, rather than watch the active speaker blather on....

Peter