As production crews continue to assemble the pieces to fill out the content creation chain for stereoscopic 3-D production that they have come to use in the 2-D world, one of the remaining parts is the wireless transmission of camera signals.
However, one of the biggest challenges when using traditional COFDM wireless camera transmission systems for two synchronized 1080p HD signals for 3-D is the availability of adequate bandwidth and ensuring reliable synchronization of images for the left and right eyes. That takes a bit of software algorithm development, which UK-based Boxx TV has said it has accomplished with excellent results.
The engineers at Boxx TV have developed the Boxx Meridian system in 2-D, which claims less than a 1ms delay and supports the use of bandwidth in the license-free 5GHz spectrum. They simply slap two Meridians together and they’ve got two high-quality HD signals that remain perfectly in sync all the way to the 3-D combiner.
“By using two separate wireless links and genlocking the cameras, everything else in the chain stays in sync,” said Scott Walker, technical director at Boxx TV. “We literally plug two Meridian systems onto each 3-D camera rig and it works. As there's ample bandwidth in the 5GHz spectrum, we just use two transmitters.”
With most COFDM systems on the market, two encoders are required, but with the Meridian system, encoders are not used. Instead, the company transmits the video in an uncompressed form with, they say, zero delay (less than 1ms).
“The Meridian transmits signals using OFDM, but because it uses a completely different way of sending video, it does not actually have a data rate,” Walker said, adding that the company has published a white paper on the technology.
The Boxx Meridian wireless camera transmitters are popular with sports and entertainment productions, including the 2010 Winter Olympics in Vancouver, and since then, they have been used on shows such as “Australia's Got Talent.” They've also been used on several Hollywood feature films shot in 3-D.
As for the demand to use wireless cameras for 3-D projects, Walker said most of the requests he’s getting for 3-D systems are for video assist capability.
“It is only a matter of time until wireless 3-D seeps into live productions,” he said. “People are talking about 3-D, and we are starting to see people looking for 3-D solutions.”
At the upcoming NAB Show in April, Boxx TV will demonstrate Meridian along with two prototype systems in action.
The first is the Boxx TV Nano, which includes a miniaturized transmitter that’s about the size the size of a cigarette pack. It leverages technology and features from the Meridian. Walker said Nano is focused on the needs of the video assist market, providing ease of use and versatility. It can be mounted on anything from a full-sized production camera to a DSLR. Boxx TV also will be showing Zenith, a new H.264 compression platform that provides greater coverage from the camera back.
“(Zenith) lets the user increase the distance covered by installing additional access points,” Walker said. “It trades a bit of latency for increased coverage and allows Boxx to provide a comprehensive microwave solution for any environment. While use cases for Meridian are generally confined to installations requiring no delay over a shorter range, Zenith has been designed for longer range requirements where a nominal delay is not normally an issue.”
