Until I read some boards online, I thought why couldn't the sports networks
on the radio get Internet into the stadiums or other remote broadcast sites
and Skype it back to the main studio, but they must've found that it
wouldn't be worth the chance that you get bad audio or drop the connection
even though it should, in theory, work if there is enough bandwidth at both
places.
----- Original Message -----
From: "Bob Seed" <bobs...@tbaytel.net>
To: "PC Audio Discussion List" <pc-audio@pc-audio.org>
Sent: Monday, January 19, 2009 10:36 AM
Subject: Re: Article: Skype's new super-wide band codec
Radio stations are using a Integrated Services Digital Network system or
specially designed broadcast software that has been designed to be used
for remote broadcasting away from the main studio. Most broadcast software
packages have the remote capability built in to them, and they sound
pretty good to the human ear. .
----- Original Message -----
From: "Kevin Wassmer" <commanderlumpy2...@earthlink.net>
To: "PC Audio Discussion List" <pc-audio@pc-audio.org>
Sent: Monday, January 19, 2009 10:28 AM
Subject: Re: Article: Skype's new super-wide band codec
This sounds very interesting. I wonder if radio stations will ever
boradcast
using Skype. I will talk to you later.
----- Original Message -----
From: "Steve Pattison" <s...@internode.on.net>
To: "PC-Audio" <pc-audio@pc-audio.org>; "vip-l" <vi...@softspeak.com.au>
Sent: Monday, January 19, 2009 4:59 AM
Subject: Article: Skype's new super-wide band codec
This article is taken from
tp://www.wirevolution.com/2009/01/13/skypes-new-super-wideband-codec. -Steve.
January 13, 2009
Skype's new super-wideband codec
I spoke with Jonathan Christensen of Skype yesterday, about the new
codec
in the
latest Windows beta of Skype:
MS: Skype announced a new voice codec at CES. What's different about it
from the
old one?
JC: The new codec is code-named SILK. Compared to its predecessor,
SVOPC,
the new
codec gives the same or better audio response at half the bit-rate for
wideband,
and we also introduced a super wideband mode. SVOPC is a 16kHz sample
rate, 8kHz
audio bandwidth. The new codec has that mode as well, but it also has a
24
kHz sample
rate, 12 kHz audio bandwidth mode. Most USB headsets have enough capture
and render
fidelity that you can experience the 12 kHz super wideband audio.
MS: Is the new codec an evolution of SVOPC?
JC: The new codec was a separate development branch from SVOPC. It has
been under
development for over 3 years, during which we focused both on the codec
and the echo
canceller and all the surrounding bits, and eventually got all that put
together.
MS: What about the computational complexity?
JC: The new codec design point was different from SVOPC. SVOPC was
designed for use
on the desktop with a math coprocessor. It is actually pretty efficient.
It's just
that it has a number of floats in it so it becomes extremely inefficient
when it's
not on a PC.
The new codec's design goal was to be ultra lightweight and embeddable.
The vast
majority of the addressable device market is better suited to fixed
point,
so it's
written in fixed point ANSI C - it's as lightweight as a codec can be in
terms of
CPU utilization. Our design point was to be able to put it into mobile
devices where
battery life and CPU power are constrained, and it took almost 3 years
to
put it
together. It's a fundamental, ground up development; lots of very
interesting science
going into it, and a really talented developer leading the project. And
now it's
ready. It's a pretty significant jump forward.
MS: Is the new codec based on predictive voice coding?
JC: SVOPC has two modes, an audio mode and a speech mode, and the speech
mode is
much more structured towards speech. The new codec strikes little bit
more
of a balance
between a general audio coder and a speech coder. So it does a pretty
good
job with
stuff like background noise and music. But to get that kind of bit-rate
reduction
there are things about speech that you can capitalize on and get huge
efficiency;
we didn't toss all that out. We are definitely using some of the model
approach.
MS: Normally one expects with an evolution for the increments to get
smaller over
time. With the new codec you are getting a 50% improvement in bandwidth
utilization,
so you can't be at the incremental stage yet?
JC: I don't think we are. We were listening to samples from various
versions of the
client going back to 2.6, now we are at 4.0. In the same situation -
pushing the
same files in the same acoustic settings through the different client
versions -
in every release there's a noticeable (even to the naked ear) difference
in quality
between the releases.
We are not completely done with it. There are many different areas where
we can continue
to optimize and tweak it, but we believe it's at or above the current
state of the
industry in terms of performance.
Beta 4 of Skype for Windows has the new codec. The current Mac beta
doesn't yet support the new codec.
Regards Steve
Email: s...@internode.on.net
Windows Live Messenger: internetuser...@hotmail.com
Skype: steve1963
Jonathan Mosen List Founder
Audio List Help, Guidelines, Archives and more...
http://www.pc-audio.org
To unsubscribe from this list, send a blank email to:
pc-audio-unsubscr...@pc-audio.org
Jonathan Mosen List Founder
Audio List Help, Guidelines, Archives and more...
http://www.pc-audio.org
To unsubscribe from this list, send a blank email to:
pc-audio-unsubscr...@pc-audio.org
--------------------------------------------------------------------------------
No virus found in this incoming message.
Checked by AVG - http://www.avg.com
Version: 8.0.176 / Virus Database: 270.10.8/1897 - Release Date: 1/16/2009
6:52 AM
Jonathan Mosen List Founder
Audio List Help, Guidelines, Archives and more...
http://www.pc-audio.org
To unsubscribe from this list, send a blank email to:
pc-audio-unsubscr...@pc-audio.org
Jonathan Mosen List Founder
Audio List Help, Guidelines, Archives and more...
http://www.pc-audio.org
To unsubscribe from this list, send a blank email to:
pc-audio-unsubscr...@pc-audio.org
