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Re: PR for API to do simulcast with RID according to Plan X

From: Peter Thatcher <pthatcher@google.com>
Date: Thu, 29 Oct 2015 05:40:01 -0700
Message-ID: <CAJrXDUGTLU+y19LgzCsEu9BsnF3t3Wa-eCkcRTCTY=3+908ggg@mail.gmail.com>
To: Bernard Aboba <Bernard.Aboba@microsoft.com>
Cc: "public-webrtc@w3.org" <public-webrtc@w3.org>, Erik Lagerway <erik@hookflash.com>, Robin Raymond <robin@hookflash.com>
1.  I think encodingId and RID are exactly the same.  It's just a question
of the name is.  I think it would make sense for both WebRTC 1.0 and ORTC
to have the field name be "rid", just like we have "payloadType" and "SSRC"
for IETF names.  But I'm don't feel strongly about it, so I'd also be happy
with "encodingId".

2.  Lots of people wanted "down" in the name to make it clear this is an
inverse.  I agree ORTC and WebRTC 1.0 ought to be consistent, but we have
to at least fit "down" in there somewhere, which probably means changing
ORTC.

On Wed, Oct 28, 2015 at 10:45 PM, Bernard Aboba <Bernard.Aboba@microsoft.com
> wrote:

> Some questions:
>
>
>
> 1.       I am wondering if we actually  need a distinct rid attribute or
> whether an encodingId attribute couldn’t serve the same purpose (and be
> more compatible with future functionality).  For example, both rid
> attribute and an encodingId attribute are DOMStrings, and both attributes
> differentiate simulcast encodings.   As a result, in the ortc-lib
> implementation, the encodingId attribute is actually used to populate the
> RID header extension so they are effectively the same thing.
>
> 2.       For consistency, I’d prefer resolutionScale instead of
> scanDownResolutionBy.
>
>
>
>
>
> Peter Thatcher said:
>
>
>
> I have written a PR reflecting "Plan X", which allows the app to specify
>
> encodings in addTransceiver:
>
>
>
> https://github.com/w3c/webrtc-pc/pull/353
>
>
>
>
>
> Obviously, this isn't of full value until addTransceiver PR has been
>
> merged, but I believe this PR is complete enough to review.  There is an
>
> example of how it can be used in the PR, where this is the relevant part:
>
>
>
>             pc.addTransceiver(track, {
>
>                 send: true,
>
>                 receive: false,
>
>                 sendEncodings: [
>
>                     {
>
>                       rid: "f",
>
>                     },
>
>                     {
>
>                       rid: "h",
>
>                       scaleDownResolutionBy: 2.0
>
>                     },
>
>                     {
>
>                       rid: "q",
>
>                       scaleDownResolutionBy: 4.0
>
>                     }
>
>                 ]);
>
>
>
>
>
> I choose the names "sendEncodings" and "scaleDownResolutionBy", but if
>
> anyone has a better idea of what to names those, suggestions are welcome. I
>
> erred on the side of verbose.
>
>
>
Received on Thursday, 29 October 2015 12:41:08 UTC

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