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Re: [codec] possible issues to track

Michael Knappe <mknappe@juniper.net> Thu, 25 March 2010 23:45 UTC

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From: Michael Knappe <mknappe@juniper.net>
To: "hoene@uni-tuebingen.de" <hoene@uni-tuebingen.de>, "bens@alum.mit.edu" <bens@alum.mit.edu>, "codec@ietf.org" <codec@ietf.org>
Date: Thu, 25 Mar 2010 16:33:53 -0700
Thread-Topic: [codec] possible issues to track
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Subject: Re: [codec] possible issues to track
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Just to clarify, is #3 what's sometimes called a fold-down scheme? (DVD-Audio for instance could generate stereo mixdowns from multi-channel content on the fly)

Mike


----- Original Message -----
From: codec-bounces@ietf.org <codec-bounces@ietf.org>
To: bens@alum.mit.edu <bens@alum.mit.edu>; codec@ietf.org <codec@ietf.org>
Sent: Thu Mar 25 19:08:56 2010
Subject: Re: [codec] possible issues to track

>I agree with Stephen Botzko that the mechanism should not be part of the requirements.  However, we
>will need to agree on an interface, i.e. the abstraction barriers.  I think:
>
>1. The codec should provide an interface for coding a pair of closely coupled channels with the
>presumption that they represent something like a stereo pair.
>
>2.  The format should provide an efficient way to pack multiple independent synchronized codec
>channels into a single stream.
>
>3. The format should provide a way to specify N named output channels as linear combinations of the
>coded channels.

Later would make the mixing in a conference server also quite easy. Just pack the encoded active streams and set the linear equation
according to the placement of the participants. Very efficient!

Christian


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