IEEE Spectrum July, 2012 - 20

hands on

Teleconferencing
on The cheap
With skype and a
little hacking, you can
teleconference with
a room full of people

A

s a telecommuter, I love
the Internet, for obvious
reasons. Strangely, though,
the teleconferencing system that IEEE
Spectrum editors have long been using
is just one step up from a speakerphone.
It only provides audio-and crummy
audio at that. As a consequence, every
editorial meeting I "attend" is a painful
experience: Imagine trying to pick
out a single voice at a noisy restaurant,
in the dark, while wearing earplugs.
A partial solution is to teleport
into meetings using Skype. Skype's
video capability gives you a window
on what's going on at the other end,
20

NA * iEEE SpEctrum * july 2012

which of course is nice. But the real
advantage is that it provides much
higher bandwidth audio than you get
over phone lines. That makes picking
out voices in a crowd much easier.
Using Skype on a laptop to attend
a meeting has some shortcomings,
though. One is the webcam's field of
view. Don't expect to take in much of
the room this way. Another is following
individual voices, which will vary in
volume and quality with how far away
the person is from the computer's
microphone. Both difficulties could be
overcome by connecting and controlling
multiple microphones and webcams.
And it turns out that with a modest
bit of hacking, you can do just that.
The key is that Skype conveniently
provides an application-programming
interface (API). With it, another
application can access many
of the Skype client's functions,
including its ability to select which
microphone and webcam are active.

Hearing aid: using Skype to
teleconference with a room full
of people works much better
when you're able to adjust which
microphone is live from the far end.
Image: DavID SchneIDer

My first attempt to use the Skype API
to pull together a cheap-but-effective
teleconferencing system used 10 separate
webcams, each with its own microphone.
I wrote a Windows program in C#,
which I dubbed MicPicker, to send
short text messages between two
computers during a Skype session.
Based on what message is received, this
software selects which webcam and
microphone the Skype client uses. So
with this program running at both ends,
a remote attendee can choose which
webcam and mic will be live during
a meeting, changing that selection on
the fly to follow the conversation.
Buying 10 webcams can get pricey,
though. I wanted the system to be
inexpensive, but I also wanted the
spectrum.ieee.org



http://spectrum.ieee.org

Table of Contents for the Digital Edition of IEEE Spectrum July, 2012

IEEE Spectrum July, 2012 - Cover1
IEEE Spectrum July, 2012 - Cover2
IEEE Spectrum July, 2012 - 1
IEEE Spectrum July, 2012 - 2
IEEE Spectrum July, 2012 - 3
IEEE Spectrum July, 2012 - 4
IEEE Spectrum July, 2012 - 5
IEEE Spectrum July, 2012 - 6
IEEE Spectrum July, 2012 - 7
IEEE Spectrum July, 2012 - 8
IEEE Spectrum July, 2012 - 9
IEEE Spectrum July, 2012 - 10
IEEE Spectrum July, 2012 - 11
IEEE Spectrum July, 2012 - 12
IEEE Spectrum July, 2012 - 13
IEEE Spectrum July, 2012 - 14
IEEE Spectrum July, 2012 - 15
IEEE Spectrum July, 2012 - 16
IEEE Spectrum July, 2012 - 17
IEEE Spectrum July, 2012 - 18
IEEE Spectrum July, 2012 - 19
IEEE Spectrum July, 2012 - 20
IEEE Spectrum July, 2012 - 21
IEEE Spectrum July, 2012 - 22
IEEE Spectrum July, 2012 - 23
IEEE Spectrum July, 2012 - 24
IEEE Spectrum July, 2012 - 25
IEEE Spectrum July, 2012 - 26
IEEE Spectrum July, 2012 - 27
IEEE Spectrum July, 2012 - 28
IEEE Spectrum July, 2012 - 29
IEEE Spectrum July, 2012 - 30
IEEE Spectrum July, 2012 - 31
IEEE Spectrum July, 2012 - 32
IEEE Spectrum July, 2012 - 33
IEEE Spectrum July, 2012 - 34
IEEE Spectrum July, 2012 - 35
IEEE Spectrum July, 2012 - 36
IEEE Spectrum July, 2012 - 37
IEEE Spectrum July, 2012 - 38
IEEE Spectrum July, 2012 - 39
IEEE Spectrum July, 2012 - 40
IEEE Spectrum July, 2012 - 41
IEEE Spectrum July, 2012 - 42
IEEE Spectrum July, 2012 - 43
IEEE Spectrum July, 2012 - 44
IEEE Spectrum July, 2012 - 45
IEEE Spectrum July, 2012 - 46
IEEE Spectrum July, 2012 - 47
IEEE Spectrum July, 2012 - 48
IEEE Spectrum July, 2012 - 49
IEEE Spectrum July, 2012 - 50
IEEE Spectrum July, 2012 - 51
IEEE Spectrum July, 2012 - 52
IEEE Spectrum July, 2012 - 53
IEEE Spectrum July, 2012 - 54
IEEE Spectrum July, 2012 - 55
IEEE Spectrum July, 2012 - 56
IEEE Spectrum July, 2012 - 57
IEEE Spectrum July, 2012 - 58
IEEE Spectrum July, 2012 - 59
IEEE Spectrum July, 2012 - 60
IEEE Spectrum July, 2012 - Cover3
IEEE Spectrum July, 2012 - Cover4
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1217
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1117
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1017
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0917
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0817
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0717
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0617
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0517
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0417
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0317
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0217
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0117
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1216
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1116
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1016
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0916
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0816
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0716
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0616
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0516
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0416
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0316
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0216
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0116
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1215
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1115
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1015
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0915
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0815
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0715
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0615
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0515
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0415
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0315
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0215
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0115
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1214
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1114
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1014
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0914
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0814
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0714
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0614
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0514
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0414
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0314
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0214
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0114
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1213
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1113
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1013
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0913
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0813
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0713
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0613
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0513
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0413
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0313
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0213
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0113
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1212
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1112
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1012
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0912
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0812
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0712
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0612
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0512
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0412
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0312
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0212
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0112
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1211
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1111
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1011
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0911
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0811
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0711
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0611
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0511
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0411
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0311
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0211
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0111
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1210
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1110
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1010
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0910
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0810
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0710
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0610
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0510
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0410
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0310
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0210
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0110
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1209
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1109
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1009
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0909
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0809
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0709
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0609
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0509
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0409
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0309
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0209
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0109
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1208
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1108
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1008
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0908
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0808
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0708
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0608
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0508
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0408
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0308
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0208
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0108
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1207
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1107
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_1007
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0907
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0807
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0707
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0607
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0507
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0407
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0307
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0207
https://www.nxtbook.com/nxtbooks/ieee/spectrum_na_0107
https://www.nxtbookmedia.com