Tools of the Trade
Training Products
Personal Consulting
Listen to the Podcast
Free NewsletterStudio
I recently started working on developing podcasts and videocasts (and some new online video products) with friends from around the country. A challenge is that most are not co-located with me.
The Problem
The problem was how to do a live podcast and videocast when you don’t have the participants in the room? I wanted to bring in guests from around the country – ideally several at a time to have roundtable discussions with myself, cohosts and guests.
A short time ago you would have needed a satellite link, studio, and many hundreds of thousands of dollars of equipment. The solution I picked was not inexpensive, but cost a few thousand dollars – well within the reach of many small businesses.
Finding a Solution
I based my studio system on Leo Laporte’s This Week in Tech studio setup at twit.tv – Leo is a legend in the podcasting community and uses skype to interview and include guests from around the country with live video on his shows. Over the years Leo has moved up to more expensive equipment (a Tricaster and high end digital audio processor), but his basic setup provided the template.
Skype is a free video chat program that runs over the internet from skype.com. Of all of the internet video chat programs, skype provides the best overall video and audio quality. Another advantage of skype is that it requires very little hardware for the guests. A typical guest needs only a USB headset, inexpensive web camera, and a high speed internet connection to join the show with live video.
The problem with skype is that it only allows one-on-one video chat. Though there is a beta version out now that does have some limited teleconferencing capability, it does not support the video switching needed for a show.
Skypeasaurus
The solution twit.tv came up with to allow multiple guests is to simply have four computers, with each running its own copy of skype – each hosting one guest. They call their system “skypeasaurus”. The computers themselves are very cheap Atom based processors in micro cases. I used the intel 945 micro motherboard in very small micro ATX cases.
- 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 (use one per computer)
- Hauppauge Impact VCB Video Capture card – low profile – $39.99
The hard drives were salvaged from old computers, and I used old copies of Windows XP I had laying around. The total cost was about $200 per machine including shipping, and I bought three to support up to three guests.
Since each computer has both SVideo out on the motherboard and a Impact VCB card to capture SVideo input, all of the guests can share their video and also see the show captured live as it occurs. This makes for a much more interactive show than a pure audio dial-in.
As an update, I later moved away from SVideo inputs, and now use primarily composite inputs for all of my video. The problem was that the SVideo connectors had a tendency to fall out when bumped, making them unreliable. The standard RCA composite cables have been more reliable and it was not difficult to transition as the video switch and most of the computer cards had both inputs available.
Leo has four dedicated monitors hooked up to his machines with a large display stand, but I decided to use a single monitor with a four port KVM switch from Amazon so I could have one monitor and keyboard, but switch them between the four machines as needed. I switch between the computers to connect the guests, but after that I can use my video switch to monitor all of the guests.
The Audio Setup
Skypeasaurus provides 3-4 skype guests with the ability to dial into the show, but we need to combine the audio from all of their machines with my personal microphone and PC (for intro music) into one audio stream for the live show.
While any good six channel audio mixer could mix the channels there is one additional complexity. You see we can’t just send the output of the show back to our skype guests. The reason is that if we just mix all of the channels together and feed it back to a given guest, he will get an echo of his own voice.
Anything they say via skype will be fed over the internet, through the mixer and right back to them via skype – delayed by a second or so. This would be impossibly annoying for the guests.
The solution is to provide what is called “mix-minus” in the audio world – essentially a mix of all of the channels except for the guest who is dialed in. The problem of course is that you need a mix-minus for each skype guest – which means three to four dedicated mix channels providing everything but the guest’s own voice back to them.
The easy way to provide mix-minus on a mixer is to use what is called the auxiliary channels on the mixer. Each auxiliary channels is essentially its own independent mix, so all one needs to do is set the knobs for all of the channels on except for the one the person is talking on to get mix-minus from the auxiliary channel.
You need one auxiliary channel for each skype machine, so for a 3-4 guest setup you need a mixer with four aux channels. This generally drives you to a larger mixer, as small mixers have only 1-2 aux channels.
The mixer I settled on was a Mackie Onyx 1620i FireWire Recording Mixer
, which is a 16 channel mixer with four aux channels to support up to four skype guests. It also has firewire built in for every channel, so I can independently record each guest’s audio channel along with my own, the aux channels and the master mix. This is a huge benefit in post processing if one of the guests has poor quality audio as I can separately correct their channel using software and then remix it after the fact.
My microphones and PC each get their own channel input on the mixer, as does each skype machine. The auxiliary outputs from the mixer provide the mix-minus needed to go back to the skype machine guests. I also use a compressor-gate-limiter on my live microphones to minimize live noise, but this is not a hard requirement.
The Video Setup
Video adds a lot to a live show, and adds an element of interactivity for the guests even if you are not recording the live video. Leo Laporte uses a $12,000+ NewTek Tricaster broadcast, which provides switching and video effects for up to six S-Video channels at once.
I did not want to spend $12,000, so I went with the poor man’s video switch Datavideo SE-500 Digital A + V Switcher, Composite & S-Video Switcher – 4 Inputs
The SE-500 has four input signals that can be either S-Video or composite. I feed the output from my in-studio video camera into one channel, and the three video outputs from the skype machines into the other three channels. Using the control panel you can switch between any of the four inputs as well as display split screen, picture-in-picture or even quad channel view to show all four people on the output at once. It also supports simple transition effects such as fades, swipes, etc – all live.
There are two main outputs – one shows a split screen quad view which you can feed into a TV if you want to monitor all of the guests at once. The other is the main output which shows the live video feed output.
This main output on my system is fed into a cheap S-Video splitter so I can send the live SVideo output back to each of the guest skype machine’s capture cards as well as a TV monitor to watch the live feed. To record the show or broadcast it live over the internet you can also push the live output to a laptop or computer with a video capture card.
One item I forgot to mention is that you do need good bandwidth coming into the studio. I have Verizon FIOS (which is fiber optic) running at 25Mb both up and down. This provides good performance, but you will find that many cable providers provide a very limited upstream bandwidth – this can be a real problem if you are trying to push three skype video channels upstream plus potentially a live video and audio stream for broadcasting. You need a minimum of 2-3Mb upstream to do this, with 5Mb being much better. For most providers this is considered business class service.
How Well Does it Work?
The system looks like a monster once you have all the wires hooked up (many dozens of wires), but when you consider the cost (~$2,600), and the capability to do a live audio and video broadcast with three guests who can be just about anywhere in the world, its a pretty amazing setup.
I’ve done a number of recorded podcasts, and have the ability to stream live as well- just like the system it is modeled after at live.twit.tv. While I have not published a lot of video primarily due to time constraints from other projects, I plan to start offering more video later this year.
The system is easy to use once it is set up. I bring the skype guests in one at a time on the skype machines, start recording the audio and video, and after that I can run the whole show using the video switch by moving from guest to guest as they talk.
Since I have a four channel compressor-gate-limiter on the audio channels and full control over audio levels, I usually have to do only minimal post processing on the audio to create a podcast. The video transitions are also captured live, so video post processing is also minimal. Essentially the output is very close to what you see on live.twit.tv, except I don’t have the ability currently to do live captioning of the guest’s names.
I like the ability to display all four guests live on my TV-monitor as well as the ability to do picture-in-picture and professional transitions with the video switch. When I have less than three skype guests, I can use my extra PC to do a live view of the internet and computer, which is great for showing a web page, online video, doing an ad or demonstrating some software. I could use the same setup effectively for software training videos or other product demos.
Overall I’m very happy with the studio. I’m planning to add a second in-studio mic and camera to support a live guest and also give the studio a full workout in the fall when I start broadcasting at least twice weekly.
Contact us if you have any questions, comments or thoughts!
—–
Upchuckr.com Internet Web Directory
