The Skypesaurus Story
Monday, March 16, 2009 at 4:08PM 
We're still working on incorporating Skypesaurus into the work flow at TWiT Live. For those who haven't seen the beast, Colleen has combined four independent Windows PCs to run four instances of Skype into one monster beast: The Skypesaurus. Rawr!
We had to do this because Skype only allows one video-caller at a time and some of our shows have as many as four online panelists. We tried software solutions like Oovoo and iChat but they didn't give us good enough audio and video - Skype really is the king for that.
Here are the specs for each PC (with the Newegg SKU numbers and price):
- 11-234-020 Case: WINSIS|WI-01 RT $43.99
- 13-121-359 Motherboard: INTEL BOXD945GCLF2 945GC ATOM330 $79.99
- 20-145-098 RAM: 1Gx2|CORSAIR VS2GBKIT667D2 R $24.99
- 22-148-231 Hard Drive: 80G|SEAGATE 7K 8M SATA2 ST380815AS $34.99
That's about $175 per computer. Add four Acer V173B 17" LCD monitors for $107 each. and a $285 Ergotron Quad-Monitor desk stand and the total rig cost just under $1500, minus Colleen's time and miscellaneous cabling.
On shows with multiple hosts (like TWiT, MacBreak Weekly, and the Gillmor Gang) we use Skypesaurus to call as many as four participants and put their audio and video on the air. This requires some hairy routing, and those of you who have tuned in in the past couple of weeks have probably noticed an hour of sweating, crawling under the desk, and general gnashing of teeth before each show. I start by setting up the audio. Each machine's output has to be routed into our mixer, and a mix-minus has to be sent back to it (that's the full audio mix minus the audio from the particular Skype we're feeding it back to, so there's no echo). Our Mackie Onyx 1620 mixer only has four AUX busses so we have to repatch audio each time we want to use Skypesaurus. Something similar happens with video. The Tricaster Studio switcher we use only has six inputs, all of which are used by cameras now. I disconnect four of those cameras and connect the four Skype boxes each time I want to use Skypesaurus. But we've come up with a solution. Today Colleen is installing a new mixer: a $1300 Mackie Onyx 1640. It's a bit bigger but it has six AUX busses and four sub-mixer channels so we won't have to repatch audio each time we use Skypesaurus. I wish I had bought this mixer three years ago - it's a beauty. We'll keep the 1620 for roadshows, but the 1640 is going to be our day-to-day mixer. For a while.
I say "for a while" because Telos called last week after hearing about our issues with Skypesaurus audio and offered to lend us one of their new Axia IP-mixers which automatically does mix-minus to every channel! An IP mixer uses Ethernet to route audio and is fully digital. There's really no mixer at all, just two IP head units in a rack and a control surface that only looks like a mixer. All-digital production means we don't have to do the noisy digital->analog->digital conversion we're doing for all our Skype audio right now. We'll just take digital audio from the PCs and pump it directly into the Axia. Putting in this puppy is going to require major reengineering for our entire audio chain. Instead of the Firewire audio we're passing from the mixer into Audition, for instance, the Axia just sends packets to Audition which uses a custom driver to see all the channels. I think a fully digital production workflow will really improve the overall quality of all our audio, but it's a big change and might take a while. In the meantime, I'm very happy with the Onyx 1640.
I also want to stop crawling under the desk to switch the video cables, so we're going to buy an Matrix Video Router. I'm about to order a $1000 Knox Video Technologies 8x8 Matrix Switcher. This takes eight video inputs and switches them to any eight video outputs so I can just push buttons and switch-in the Skype output for a camera (and out again on the fly if I need more shots). In effect this gives us four more cameras. If there are any TV broadcast engineers who have some suggestions here I'd love to hear them. Everything is S-Video so this seems like the best way to do it but we're babes in the woods when it comes to this stuff.
So there you have it. Problem: how to get four hosts' audio and video on the air at once via Skype. Solution: Skypesaurus, a $3500 monster designed and built by the amazing Colleen. We're pretty excited about it - it's not the CNBC Octobox, but it's pretty close and for a heck of a lot less money.
Skype, Skypesaurus, TWiT Live in Blog 
TWiT started as 
bear has set up a Jabber server for us at twit.im. That's the engine that would power this river. Now it's time to think about how we'll implement the user interface, both for readers and contributors. I'd like to make it easy enough to use that readers naturally become contributors.
Aside from installing a server and buying the domain twit.im, we haven't done anything else. So the following is purely speculative. I'd like to get your comments on it before we begin implementation. Consider the following an RFC.
The best interface to this river would, I imagine, be an IM client, but as with any stream there might be other ways to view it, in a Friendfeed room, on a dedicated web site, as a ticker on live.twit.tv, etc. I think these instances can be created by the TWiT community as needed over time. And since the river is just an XMPP stream it should be very simple - the API already exists. I would also like to have a real-time RSS feed of the full-river - that should make it pretty easy to write viewing tools. But initially, any Jabber-compatible IM client, 
I would also like to be able to create special-use instances of the river. For example, at my Macworld keynote, I'd like to be able to create a one-time use backchannel, say macworld@twit.im, that attendees could post to and follow, and that, perhaps, I could put up on screen.
At this time we don't have any plans to let users register for twit.im accounts. I don't want to bog the server down with additional duties. It's going to be busy enough as it is. But if you have an existing GTalk or Jabber account you'll be able to use that.
What do you think? Have I missed anything? Is there any functionality you'd like to add? Please add your comments below. Thanks!