Engineering the 3D OB transition1 March 2010
Routing specialist Axon helps Belgium’s Outside Broadcast adapt to live 3D broadcast productions, reports Neal Romanek.
An axon is the part of a nerve cell that sends one cell’s signal on to the next nerve cell. Without an axon, a nerve cell might be overflowing with great ideas, but its fellows will never know about them. Axon Digital Design, headquartered in The Netherlands, has specialised for years in producing hardware for the transmission, processing, and routing of audio and video signals. Now they’re becoming a key player in getting 3D signals where they need to go.
When Belgian HD producer Outside Broadcast wanted to demo the live 3D transmission of an athletics event at last year’s IBC, it went to its time-tested partner Axon. Outside Broadcast was already using Axon’s Synapse infrastructure. Their challenge for Axon was not “Can we get some new technology which will allow us to do something new?” but “How can we do something new with the technology we already have?”
The Memorial Van Damme, an annual summer event being held in Brussels at the King Baudouin Stadium, concurrently with IBC, provided a perfect opportunity to give professionals a taste of the future of live 3D. “Our Synapse modules are a hot-swappable solution,” explains Axon Chief Technology Officer Peter Schut. “The infrastructure’s already there. For Outside Broadcast, we modified existing hardware to cope with their requirements, so they didn’t have to rewire anything. It’s very convenient if we can add these features to existing hardware.”
The principle requirement for the 3D transmission was to handle two simultaneous signals of left and right eye information provided by the stereoscopic camera rig. Outside Broadcast used a mirror splitter stereo camera rig – and so also added the necessary flipping of the mirrored image. Axon modified their existing HXH150 card.
For the 3D transmission two left eye and right eye sources needed to be combined into a single SDI (HD) video stream. This was accomplished by squeezing both images down to an anamorphic half-horizontal size, then displaying them in a side by side mode compatible with MPEG transmissions.
“It was combining software blocks that we would previously use for other purposes,” Schut says. “The card was designed to provide a 4:3 image with a pillar-box on each side to contain additional, external information. It was already ready to receive data from two sources. It was then just a matter of ‘moving the curtains around’ and the scaling algorithms."
Outside Broadcast’s 3D demo was so impressive that Axon was asked by EuroMedia for support in its wireless 3D broadcast from camera motorcycles 2009 of the Tour De France and the Tour De Paris in what became the world’s first live 3D HD coverage from a motorbike.
For the event a motorbike was equipped with a HD stereoscopic camera system provided by French rig specialist Binocle. The dual signals were combined and synchronised into one HD-SDI video stream as before by the HXH160, mounted onto the motorbike.