Re: [AVT] Audio Level Indicators - new versions submitted
Stefan Sayer <stefan.sayer@iptego.com> Thu, 22 October 2009 10:52 UTC
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Date: Thu, 22 Oct 2009 12:52:35 +0200
From: Stefan Sayer <stefan.sayer@iptego.com>
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Cc: "Audio/Video Transport (AVT) WG" <avt@ietf.org>
Subject: Re: [AVT] Audio Level Indicators - new versions submitted
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Hello, o Emil Ivov [10/22/09 11:25]: > All, > > As requested by the chairs several weeks ago, Jonathan, Enrico and I > have submitted new versions of the client-to-mixer [1] and > mixer-to-client [2] audio level indication drafts. Both documents Why not use the (so far unused) MSB of the audio level in the mixer-to-client extension header as voice activity flag (live the V in client-to-mixer) ? While it is possible for the mixer, it may be impossible for the client to accurately determine voice activity of the participants (e.g. the spectral information is lost). The format would then look like this: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ID | len |V| level 1 |V| level 2 |V| level 3 ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: Audio level indicators extension format An open question would be whether this is mandatory, or how a mixer could signal that it is not doing voice activity detection (i.e. V will be zero all the time). Stefan > [1] - http://tools.ietf.org/html/draft-lennox-avt-rtp-audio-level-exthdr > > [2] - http://tools.ietf.org/html/draft-ivov-avt-slic > _______________________________________________ > Audio/Video Transport Working Group > avt@ietf.org > https://www.ietf.org/mailman/listinfo/avt -- Stefan Sayer VoIP Services stefan.sayer@iptego.com www.iptego.com IPTEGO GmbH Wittenbergplatz 1 10789 Berlin Germany Amtsgericht Charlottenburg, HRB 101010 Geschaeftsfuehrer: Alexander Hoffmann
- [AVT] Audio Level Indicators - new versions submi… Emil Ivov
- Re: [AVT] Audio Level Indicators - new versions s… Stefan Sayer
- Re: [AVT] Audio Level Indicators - new versions s… Stefan Sayer
- Re: [AVT] Audio Level Indicators - new versions s… Enrico Marocco
- Re: [AVT] Audio Level Indicators - new versions s… Enrico Marocco
- Re: [AVT] Audio Level Indicators - new versions s… Emil Ivov
- Re: [AVT] Audio Level Indicators - new versions s… Emil Ivov
- Re: [AVT] Audio Level Indicators - new versions s… Stefan Sayer