From: "Charles Eckel (eckelcu)" <eckelcu@cisco.com>
To: Kevin Gross <kevin.gross@avanw.com>
Thread-Topic: [MMUSIC] Channel descriptions
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Date: Wed, 18 Jul 2012 22:03:22 +0000
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Cc: mmusic <mmusic@ietf.org>
Subject: Re: [MMUSIC] Channel descriptions
Precedence: list

It looks as if RFC 3190 defines some conventions for the channels for L24.
Otherwise, perhaps an extension to RFC 5576, assuming you are using differe=
nt SSRCs for each channel.
In general, there are ongoing discussions ongoing in AVTCORE, RTCWEB, and C=
LUE regarding multiplexing and some mechanism to describe the multiplexed s=
treams will likely result.

Cheers,
Charles

> -----Original Message-----
> From: Kevin Gross [mailto:kevin.gross@avanw.com]
> Sent: Wednesday, July 18, 2012 10:35 AM
> To: Charles Eckel (eckelcu)
> Cc: mmusic
> Subject: Re: [MMUSIC] Channel descriptions
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> Yes. For a multichannel media specification such as:
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> 	m=3Daudio 49152 RTP/AVP 96
> 	i=3DChannels 1-8
> 	a=3Drtpmap:96 L24/48000/8
> 	a=3Dsendonly
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> I get one description ("Channels 1-8") for all 8 channels in this stream.=
 I'd
> like to also have the ability to supply a description per channel.
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> Kevin Gross
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> +1-303-447-0517
> Media Network Consultant
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> AVA Networks - www.AVAnw.com <http://www.avanw.com/> ,
> www.X192.org
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> On Wed, Jul 18, 2012 at 9:58 AM, Charles Eckel (eckelcu)
> <eckelcu@cisco.com> wrote:
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> 	Hi Kevin,
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> 	Just to clarify my understanding of what you are asking, you can
> already have an i-line at the session level and/or at the media level (i.=
e. per
> m-line). Are you looking for something that lets you differentiate betwee=
n
> multiple channels within a single m-line?
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> 	Cheers,
> 	Charles
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> 	> -----Original Message-----
> 	> From: mmusic-bounces@ietf.org [mailto:mmusic-
> bounces@ietf.org] On
> 	> Behalf Of Kevin Gross
> 	> Sent: Tuesday, July 17, 2012 4:58 PM
> 	> To: mmusic
> 	> Subject: [MMUSIC] Channel descriptions
> 	>
> 	> The i=3D attribute provides a means to describe a session. Sessions
> often have
> 	> multiple media streams or channels. Although RFC 3551 (page 8)
> suggests a
> 	> convention for ordering of channels for surround sound
> applications, other
> 	> applications use multiple channels in different ways. It would be
> useful if
> 	> there were a mechanism analogous to i=3D for describing individual
> channels
> 	> in a session. Does such a thing exist anywhere? I've searched the
> archives
> 	> here and didn't find anything.
> 	>
> 	> Kevin Gross
> 	>
> 	> +1-303-447-0517 <tel:%2B1-303-447-0517>
> 	> Media Network Consultant
> 	>
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> 	> AVA Networks - www.AVAnw.com <http://www.avanw.com/> ,
> 	> www.X192.org
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