Unmanned Systems Technology 038 l Skyeton Raybird-3 l Data storage l Sea-Kit X-Class USV l USVs insight l Spectronik PEM fuel cells l Blue White Robotics UVIO l Antennas l AUVSI Xponential Virtual 2021 report

6 Mission-critical info for UST professionals Platform one A video transcoder maker is supplying a system for the Mayflower Autonomous Ship (MAS) that is due to sail across the Atlantic soon (writes Nick Flaherty). Videosoft has developed a system that can deliver video from multiple cameras on the ship over a satellite link back to mission headquarters in the UK via IBM’s cloud computing network. Stewart McCone at Videosoft said, “We put a video source processor next to each camera. That ingests the video, whether it’s HDM, HD-SDI or compressed, and takes it back to its raw state and then recompresses the video. Then we make that video available to the comms protocol and a server that distributes the video. “The system can be used on its own for viewing live video from a camera, or dovetailed into a wider system. Built into it is the ability to automatically measure the network bandwidth and adapt to that. That’s critical, as you don’t want any delay. We have techniques to increase or decrease the bandwidth automatically to keep a feed live. The system compresses data from the camera to a rate of 1 Mbit/s down to 6 kbit/s. “We do decompression and scaling on the fly depending on the scene, and the bandwidth can be allowed to drop if the scene is static,” McCone said. This is typically at CIF and quarter-CIF resolution. “For the MAS we will use a mix of H.264 and H.265 compression standards, and there are other things on the market we can bring into this. The MAS has given us a target of 200 kbit/s for six cameras. We give the client a switch to change the profile, so they can run 6 kbit/s on one camera or use the whole 200 kbit/s for one camera.” The inputs are not related to the output stream, so each stream is an independent bandwidth-managed channel and can switch any of those streams to the output. “In the MAS we have six streams configured, and whenever a user wants they can increase the bandwidth coming from a camera,” said McCone. “At the same time, we are recording at the source. “When the AI system controller on the Mayflower detects an event it tells the video system to bookmark it in storage, and that will be replayed from the storage over the link so you can determine whether you want that event and then download at native quality.” The system for the MAS has been optimised for satcom links. “Latency is a big issue with satcom, so we have to break the data into packets,” McCone said. “The content is repackaged into a standard protocol so the link is transparent to the client.” Marine vessels Live look-out on voyage June/July 2021 | Unmanned Systems Technology The Mayflower’s live video system is designed to adapt to changes in bandwidth

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