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Re: Simulcast V1

From: Bernard Aboba <Bernard.Aboba@microsoft.com>
Date: Fri, 14 Aug 2015 17:31:02 +0000
To: Stefan Håkansson LK <stefan.lk.hakansson@ericsson.com>
CC: Adam Roach <abr@mozilla.com>, "public-webrtc@w3.org" <public-webrtc@w3.org>
Message-ID: <567241F9-C938-4C15-9966-9A9DE1ECB45F@microsoft.com>
On Aug 13, 2015, at 23:21, Stefan Håkansson LK <stefan.lk.hakansson@ericsson.com> wrote:
> 
> We already have a form of "poor man's" simulcast: create several tracks 
> that connect to the same source, attach them to individual RtpSender's, 
> and apply different constraints and different sender settings to them.
> 
> In my personal opinion we should determine whether or not this would be 
> sufficient before adding new functionality.

[BA] That depends on what assumptions are being made about Selective Forwarding Unit (SFU) behavior and simulcast multiplexing. 

As an example, if the SFU is assumed to send only a single stream to the receiver, there is only "simulcast" being sent, not received. In that case the only potentially relevant parameter is the maximum number of streams that can be sent.

Of course it is also possible for the SFU to send multiple streams and SSRCs to the receiver, with or without distinct payload types for each.  In that case an RtpReceiver needs to be able to receive multiple streams and produce a single track from them, so it is considerably more complex. 
Received on Friday, 14 August 2015 17:31:30 UTC

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