Mediahaus delivers the first SRT live-streaming sports production over 5G with URSA Broadcast G2

Watching the live broadcast on Austrian sports streamer LAOLA1.TV, as well as YouTube and Facebook, you’re struck by three things: the gruelling races take place over a massive area, it all looks freezing, and it can be very dark on those summits. None of these factors are beneficial to sports broadcasting.

Nevertheless, this was the arena that host broadcaster Mediahaus GmbH chose for a proof of concept remote production of live SRT streaming from Blackmagic USRA Broadcast G2 cameras over a 5G network.

Need for speed

Mediahaus, based in Salzburg has been the host broadcaster for the past dozen years, but this year for the first time, it was able to send live H.264 streams from its URSA Broadcast G2 race cameras using SRT, a protocol optimised for live video streaming, down the mountains to its outside broadcast truck in Saalbach. 

Working with Hutchinson, Mediahaus utilised a standalone 5G network to bring live camera feeds with incredibly low latency from the mountaintops to the production team and the director, Wolfgang Angermüller, in the Mediahaus OB van.

“Eleven years ago, when we started working with the race founder Roland Kurz, it was quite a challenge just to get two cameras on two summits,” recalls Angermüller, CEO of Mediahaus.

“Last year, we had four cameras on four summits, each connected through SDI to an encoder and then via an IP connection provided by a modem in the infrastructure of the cable car. We also had two mobile cameras on skidoos using bonded cellular from Mobile Viewpoint. But it took us two days to set up all the cameras and encoders on the mountaintops.

The Mediahaus proposal to use SRT and 5G was inspired by new technology from Blackmagic Design and the fact that Hutchison, one of the supporters and sponsors of the event, was building a standalone 5G network in the valley below Saalbach. 

“The skiing world championship takes place in the valley next year, and the 5G private network was ready in December,” recalls Angermüller. “But we were also lucky that Blackmagic’s new Camera 8.5 beta release allowed SRT streaming out of our URSA Broadcast G2s; we would just need to plug in a mobile phone to send the H.264 feeds.”

Uphill trial

Mediahaus conducted tests of SRT over 5G, first in the lab with Hutchinson in Vienna, then with Blackmagic Design’s ATEM Streaming Bridges as receivers in the OB truck.

These compact video converters receive and decode the SRT streams, with those feeds then fed into an ATEM Constellation 8K live production switcher via SDI while sending camera control and tally signals back up to the camera using the same data link.

Two weeks before the event, a real-world test took place in Saalbach. “We got up to a summit, and with just a normal Samsung mobile phone connected via USB-C to the camera, we were streaming SRT at 5Mb/s output. We had a latency of half a second, which is nothing,” Angermüller says.

The mountains blocked certain positions from the 5G antennas in the valley, so a connection to the Starlink satellite network was deployed on one summit. “That worked well, with just half a second latency,” says Angermüller. “On another summit, we had two WiFi access points, so if there were no 5G, the mobile phones would switch to the public internet. But it’s always the same SRT connection via a mobile phone.

At the finish line, the OB gallery using an ATEM Constellation 8K for vision mixing had all the camera telemetry data to hand, giving them control over the camera’s colour grading, shading, and shutter speed through the ATEM Camera Control panel. “It was as though it was connected directly via cable,” says Angermüller. “The other significant advantage was that we now had tally lights on the summit cameras to let the operators know they were live.

“One of the hardest summits to reach turned out to be the summit where 5G worked without any problems,” he continues. “Our operator took his camera and the mobile phone and headed up there. It was so much easier not needing to bring an encoder and SDI cables; the camera battery powered the phone. We saved a whole day of working time with this approach.

Conditions in the mountains were as low as -15 °C with heavy snow, and as the races started at 4pm, they ended at night. However, despite the conditions, the colour science, the resolution and the dynamic range of the URSA Broadcast G2 served Mediahaus well in this unforgiving environment.

Dramatic live coverage of the Mountain Attack race certainly proved the case for live production using SRT streaming out of the URSA Broadcast G2, but Angermüller says the best moment took place one hour before the race. “All the cameras were on the multiview in the OB van, and the vision engineers said they’re all connected, they have tally, and everything is working,” he concludes. “When they said, ‘we got them all’, it all came together.”