DigiTek Systems

TriCaster and Skype integration at Inside Carolina studio installation

We recently installed a new studio facility forInside Carolina in Chapel Hill, NC. Inside Carolina follows football and basketball at UNC Chapel Hill. While well-established as a print, radio and web entity, live video-streaming was an entirely new venture for Inside Carolina. Buck Sanders at Inside Carolina contacted Matt Drabick at NewTek-dealer DigiTek Systems for hands-on information about using the TriCaster for streaming high-definition live video. After some intensive research, including visiting various local facilities using a TriCaster purchased from DigiTek Systems, Buck decided to go with the TriCaster 450 EXTREME and TriCaster 450 CS control panel as the heart of his new live-streaming facility.

Buck visited the Wake Forest, NC studio of Vance Willis, part of the TTFN organization, which produces a live weekly program on streaming and production equipment. Buck liked what he saw at Vance’s operation and used it as a model for his new facility. Besides the TriCaster, Buck went with three Canon Vixia HF G10 hi-def video cameras, a full green-screen wrapped around the back wall of his studio space plus a Mac mini with a Blackmagic Intensity Extreme Thunderbolt box as his Skype computer.

While DigiTek Systems has installed a number of new and existing studios with TriCasters over the years, the Inside Carolina studio was the first time for integrating a Skype computer that would allow a remote caller to be part of a live show. Additionally, the Inside Caroline studio talent and guests would always be inserted into a virtual set, requiring studio lighting that allowed a clean chroma-key.

Several challenges immediately presented themselves during the design of the studio. First was the size and shape of the actual room used for the studio, approximately 16 by 10 feet with a relatively low ceiling. Knowing that at least two, up to four, people would be on camera at the same time required using the 10-foot back wall of the room where the talent and guests would sit or stand. The limited 10-foot width of the room required moving the three video cameras to the other end of the room.

Initially one Canon HF G10 camera was center-mounted on a tripod while the other two HF G10 cameras were wall-mounted on either side of the room. Ultimately we lowered the two wall-mounted cameras about 10-inches to avoid “looking down” on the talent. The tripod camera, while working well for the wide-shot, was eventually mounted on a ceiling pole that allowed the camera to be repositioned up and down to allow the talent and guests to be sitting or standing up. 

Originally the room walls were painted a glossy white. Knowing that green light would bounce back onto the talent and guests and make it difficult to obtain a clean chroma-key for the virtual set, required painting all of the walls (fittingly enough) a flat Carolina blue to avoid green bounce-back.

While the room’s fluorescent lighting required adding of studio lights for a clean chroma-key, the room’s air-conditioning air handler was loud enough to be heard by an open microphone. This meant that the AC had to be turned-off during a live show, which required pre-cooling the room before each show AND not using studio lights that give off any appreciable heat. 

Phil Johnson of DigiTek Systems recommended using Cool Lights which offers both broad and focusable lights that give off very little heat. We used a pair of ceiling-mounted Studio Flo lights with two lamps each to light the green screen and four CDM 70 Fresnel lights ceiling-mounted in each corner of the room to act as two back lights and two key lights. All six lights were balanced for 5600K/5400K or daylight. Given the relatively small size of the room, the six lights gave off plenty of light to help generate a clean video signal from each camera, resulting in a clean chroma-key without heating up the room.

The Skype computer was the biggest challenge for this installation. We needed to see and hear the Skype caller as a video input to the TriCaster. We needed to send the live show feed back to the Skype caller without adding any audio feedback. And the studio talent and guests needed to see and hear the Skype caller in the studio during the live show.

The Mac mini outputs HDMI video. We added a Blackmagic Intensity Extreme Thunderbolt to bring audio into and out of the Mac mini. (You need to purchase the Thunderbolt cable separately). We added a Behringer Shark to allow for audio delay (the video gets delayed behind the audio so you need to “slow down” the audio to get both in sync with each other).

Another audio issue is the need to subtract the Skype caller from the audio mix that is sent back to the caller from the TriCaster. This requires using an audio mixer that allows for a mix minus (a sub-mix without the caller added in). We used a Mackie 1604-VLZ3 and it worked flawlessly.

To send the Skype caller’s video to the TriCaster plus the studio’s Skype monitor and to the Mac mini’s own monitor, we connected a Blackmagic HDMI to SDI mini-converter to the Mac mini’s HDMI port. One of the SDI feeds from the miniconverter was sent to the TriCaster as the fourth switcher input (the three Canon HF G10 video cameras were the first three inputs on the switcher). The miniconverter’s second SDI output was sent to a Blackmagic SDI to HDMI miniconverter. The HDMI output of the miniconverter was sent to a generic 1-in, 4-out HDMI distribution amplifier or DA. One HDMI output from the DA was sent to the room’s Skype monitor, while a second HDMI feed was sent to the Mac mini’s monitor.

We discovered that you can’t split the HDMI output of the Mac mini more than twice. Originally we went from the Mac mini to the 1-in, 4-out HDMI DA and then to the HDMI to SDI miniconverter to feed the TriCaster, the Skype monitor and the Mac mini monitor, but it didn’t work.

Some important notes about the Skype computer. Some XML coding was required to make the Mac mini work properly as a Skype computer. (Fortunately, Vance Willis was able to perform the required XML coding plus train the Inside Carolina staff on using their TriCaster for live streaming). We used an older driver for Skype. And you must connect a Webcam to the Mac to make it all work ever though you don't use the Webcam as a video source with the system. Be sure the Webcam you choose works with a Mac and not just Windows.

All in all, it was a very interesting installation. We learned a lot about setting up Skype to work with the TriCaster. I look forward to the next installation.

Matt Drabick, 
DigiTek Systems