W3C home > Mailing lists > Public > public-xg-audio@w3.org > December 2010

Re: Audio WG Charter, Call for Co-Chairs

From: Doug Schepers <schepers@w3.org>
Date: Wed, 15 Dec 2010 15:28:19 -0500
Message-ID: <4D0924E3.4020001@w3.org>
To: Janina Sajka <janina@rednote.net>
CC: "Penkler, David" <dave.penkler@hp.com>, Noah Mendelsohn <nrm@arcanedomain.com>, Philippe Le Hegaret <plh@w3.org>, "public-xg-audio@w3.org" <public-xg-audio@w3.org>
Hi, Janina-

I recognize the validity of your use case.  However, I think this is 
actually orthogonal to the more pressing and immediately achievable goal 
of an client-side script API for audio.  I think we are best served by 
focusing on solving that problem first, and the charter should reflect that.

However, we will note your use case as one for future consideration, 
possibly for the next charter period.  The sooner we can finish the 
audio API spec and lay the groundwork for device access (microphones and 
speaker channels), the sooner we can tackle a larger class of problems.

I don't think your use case will be hampered by the foundations we lay 
first, since it's actually quite different in nature, and as you 
suggest, may be more in scope for the RTC WG.

Regards-
-Doug Schepers
W3C Team Contact, SVG, WebApps, and Web Events WGs


Janina Sajka wrote (on 12/14/10 12:55 PM):
> Hello Doug and All:
>
> Doug Schepers writes:
>>  Penkler, David wrote (on 12/14/10 10:36 AM):
>>  >>From: Noah Mendelsohn
>>  >>>noting that streaming is out of scope except for coordination
>>  >>>with other groups
>>  >>
>>  >>Could you clarify what is meant by this?
>>  >
>>  >No it refers only to bidirectional real-time audio streams carried
>>  >over RTP/UDP or such connecting two or more users between them or to
>>  >a network interactive voice response unit such as voicemail system.
>>  >This is basically the soft phone in a browser use case. One of the
>>  >specific issues arising out of this use case is the need to
>>  >synchronise the input and output streams in order to perform echo
>>  >cancellation economically. The use cases for listening to a remote
>>  >live performance over the internet with an audio enabled web browser
>>  >or DAW's are not excluded.
>>
> I wonder if we would rather craft the charter more narrowly to exclude
> telephony and not exclude the use case of musicians performing together
> across the net?
>
>
> The latter use case is already well supported in the CELT codec from
> Xiph:
>
> http://www.celt-codec.org/
>
> Quoting this page:
>
>    "The CELT codec is a compression algorithm for audio. Like MP3,
>     Vorbis, and AAC it is suitable for transmitting music
>        with high quality. Unlike these formats CELT imposes very little
>        delay on the signal, even less than is typical for
>           speech centric formats like Speex, GSM, or G.729.
>
> 	   "Using CELT application developers can build software that
> 	    allows musicians to perform together across the Internet, or
> 	       simply build great sounding telephony systems. Why
> 	       shouldn't your telephone sound as good as your stereo?"
>
>
> I confess I have yet to use CELT to add my musical contribution to a
> performance, but I am well satisfied by the high quality of CELT and can
> testify to its low latency from having used it often in Vo/IP calls
> between Washington, DC and Melbourne, Australia. Yes, my experience is
> telephony, not musical performance--but the use case is real, imho, and
> should be supported.
>
> Do we expect realtime communications to support this use case? I don't
> know that I have a preference one WG over another--just that the use
> case get due consideration.
>
> Janina
>
Received on Wednesday, 15 December 2010 20:28:30 UTC

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