[Wikimedia-l] WMCH resolution about providing a web conferencing system for the Wikimedia Movement

[Manuel Schneider]

Hi Fæ and all,

Richard already contacted me offlist concerning A/V equipment for
conferences, so I thought it makes sense to reply on-list (Richard's in
CC) to make this information available broadly.

Anyway, I am not claiming that I have the best solution nor the best
knowledge on this topic but some experience. Others please add their
solutions and experiences.

For an inexpensive audio and / or video conference we need components
which we can easily connect to a PC and will be recognized by the
operating system as simple audio or video inputs, like a webcam and a
soundcard. If we stick to these standards we can use any conferencing
software we want - be it Skype, Google Hangout or Big Blue Button (which
uses simply Flash).

== Video ==
=== Webcams ===
Built-ins are always inferior to USB webcams, especially the angle due
to their fixed position on the screen is bad.

When buying a USB webcam make sure that it can be used as a standard USB
imaging device. Don't buy webcams with a too high resolution! They have
small lenses catching only a little light and higher resolutions
typically mean darker / noisier images. 720p is good. You can't stream
in HD anyway.
Logitech C310 and C510 are good models.

=== Camcorder ===
Camcorder have much bigger lenses and are much more flexible in their use:
** use a small tripod
** you can set whitebalance, manual focus, shutter...
** optical zoom
** tilting LC-display - turn around so people can see how the camera
image looks like
** they can record simultaneously (on tape or SD card)
Make sure your camcorder as a DV output (Firewire). Plug it into your
computer and you can use the camcorder as a standard imaging device.
Again, you don't need HD for a video conference. At least with the
bigger lense and sensor or a camcorder it doesn't hurt too much.

I use a Panasonic camcorder, a recommendation (and gift) from the
Austrian Broadcaster (ORF): Panasonic NV-GS500.

This little tripod can be expanded up to 1m but fits perfectly in a
small bag and gets through hand-baggage on an airplane:
http://www.amazon.de/Cullmann-50008-Stativ-Digi-Pod-long/dp/B000AM4N10

== Audio ==
=== Microphones ===
Built-in microphones are always inferior. This is true for camcorder
mics, notebook mics... For most applications they are also way too far
away from the audio source (your mouth).

==== Table / Conference Mics ====
Get extra mics. For a conference get a boundary layer microphone.
* http://en.wikipedia.org/wiki/PZM_%28microphone%29
I got this one: http://www.thomann.de/gb/superlux_e304b.htm
Like most professional mics it needs phanton power and comes with a
simmetrical connection (XLR). Symmetrical connections are less prone to
noise and other negative impact on the cabling.

==== Gooseneck Mics ====
If you need better audio quality then you need to get individual mics
for each participant. Goosenecks are best here, especially when you get
them with on-off switches, so they participants can switch themselves to
avoid disturbances.
Bundle, not switchable: http://www.thomann.de/gb/samson_cm_20_p_bundle.htm
Mic stand w/ switch: http://www.thomann.de/gb/km_29375.htm

=== Soundcards ===
Built-in soundcards don't work for professional audio equipment. They
have noise and the line input / mic input jacks don't have the right
impedances. Their power supply for condenser mics is mostly incompatible
to what we want to use.

There are great mixers which have a soundcard integrated. So you can
just plug all audio equipment together in your mixer, check the quality
via headset, plug it into your computer and get the sound right their on
its own audio channels. Just make sure before you buy a mixer that it
supports the USB 1.1 standard! USB 2.0 only means that you need special
drivers and might end up not having a generic sound interface available
in your OS.

For only two mics (eg. PZM / boundary layer) I got myself this little
sound card. It even has a small VU meter, so you can check the volume
without a headset.
http://www.thomann.de/gb/alesis_io2_express.htm
Big advantage is that this device is USB-powered. No additional cables
on you table and no additional source of noise in your audio system!

For bigger setups I got me this:
http://www.thomann.de/gb/behringer_xenyx_x1832_usb.htm
This one also supports 2-track-input so you can do more complicated
things like sound routing - this was needed to handle live translation
of Sue Gardners visit at Wikimedia Deutschlands General Assembly. I
streamed / recorded on two different back planes and switched the input
planes between translation and original audio so we had english always
on one back plane and german on the other.

These soundcards work fine under Linux with the generic USB audio driver.

=== Speakers ====
Better in virtual conferences would be headphones. Everyone knows the
negative effects in Skype meetings if somebody doesn't use a headset.
Echos and other disturbances.

Put the speakers far away from the mics but so you can still hear well
to avoid feedback. Again, individual gooseneck mics make it easier.

You can use standard speakers which can be plugged into the line-out of
your notebook.

== Conlusion ==
* USB soundard w/ 2 mic inputs and phantom power:	100 EUR
* 2x boundary layer mics (60 EUR each)			120 EUR
* pair of speakers					 10 EUR
* small tripod						 30 EUR
* Panasonic camcorder w/ DV out				300 EUR

For 560 EUR you can get yourself a decent video conferencing equipment.

Once you have everything connected to the PC make sure it has installed
all the drivers for camera and soundcards and make a restart to be sure
all devices work before you start the conference.
Once you start Skype, Hangout, whatever, make sure the application uses
the right video device (DV camera), audio input device (USB soundcard)
and audio output device (internal soundcard). Check "Settings".


/Manuel
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