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In the Field: Teradek Live:Air

Live:Air gives the user the ability to switch among up to four cameras while mixing in titles, graphics, and pre-recorded b-roll. While the theoretical capabilities of such a setup are very exciting, the technological limitations of current iPad models are keeping the system from reaching its full potential.

Event Day

Once the kinks in setup were all worked out, it was time to start testing the app's capabilities and performance. Live previews from the three VidiU units came through clear and very close to the frame rates the cameras were sending.

We set up a test stream on YouTube Live using RTMP, which ran beautifully. Occasionally we would see a “stream not available” message pop up in red over one of the sources, but it would only be up for a second or two before the camera feed came back. Later, we realized that this was probably due to the older iPad’s lack of processing capability. After a few hours of testing under different circumstances, we had a good idea of how we would set up for our live event.

Stream not available. Click the image to see it at full size.

Event day arrived with more challenges than our test run had led us to expect. Using all of the same equipment except for our wireless router, we had significant connectivity problems. The VidiUs had trouble connecting and staying connected to the iPad which caused us to have to restart the entire system repeatedly.

Due to the aforementioned long startup times for each unit, we spent several hours just starting and restarting VidiU units. Once we established what seemed to be a reliable connection among everything, we tested a 720p stream to YouTube Live. Everything checked out OK, but it was tenuous. We were still getting intermittent “stream not available” messages from units.

When the broadcast began, things fell apart entirely. It was quickly apparent that we could not maintain three 1080p camera feeds as well as the iPad’s built-in camera. The stream was completely unwatchable and laggy with broken audio. Jacob started eliminating cameras, and ended up going down to just one camera, 720p and broadcasting a 480p signal to YouTube. That finally provided a stable stream.

CPU load maxed out on iPad at 1080p

CPU load normal with 720p

Teradek’s Take

After a discussion of our problems with Teradek, it was again recommended that we try our setup on an iPad Air 2. They suggested that most if not all of the problems were related to the iPad’s inability to process all of the data being thrown at it. So after a trip to Best Buy, I returned to our “lab” with a brand new Air 2, and we attempted to re-create our scenario.

This time, we tried just two and three cameras (including the iPad’s built-in camera) at 1080p. Despite the business class dual-band router and completely isolated network, we still had an unusable stream at 1080p. Reducing all resolutions in and out to 720p made a mostly stable stream possible with occasional audio drops. It was at this point that Jacob and I found what we believe to be the weak link in the entire system.

Jacob grabbed screenshots of the Live:Air interface on the iPad so we could compare stats later. As you can see, the 1080p stream was very taxing on even the powerful iPad Air 2. The processor usage ranged between 90% and 100% the entire time. Dropping things down to 720p made a dramatic difference, lowering the CPU load down to 10%-20%. Not surprisingly, this gave us a stable stream with few audio drops. Our conclusion: the iPad isn’t capable of handling everything the Live:Air app can dish out.

A conversation with Corey Behnke of Live X helped put a few things in perspective about this system as well. He has an article in an upcoming issue of Streaming Media magazine where he’ll go into depth about his experience with the Live:Air app on a shoot for the Green Bay Packers.

When Corey first heard about the Live:Air app on an iPad his reaction was, “No way!” Although he knew the prospect of live switching multiple H.264 feeds on an iPad was probably not going to work very well, he also knew he’d buy into it since it enabled him to be more mobile and portable than ever before. Plus it was a cool selling point to his clients: “Live switching on an iPad?! Yes, please!”

Teradek’s Gabe Phan confirmed some of the issues we found and provided some explanations. He agreed that their products lack documentation and clear setup instructions but that they are working on improving that. Phan said, “In the latest release, we included a FAQ in the app to answer some of the questions that our customers were having. It also includes a matrix of what is capable with each iOS hardware.” He also stated that they will be limiting the app’s stated capabilities in future updates. They haven’t done this yet because “right now, there is not a clear line of what is capable or not.”

An iPad Issue

While I left this project feeling very underwhelmed by the capabilities of the Live:Air/VidiU system as a whole, I found some needed perspective. Doing a three-camera 1080p stream with an iPad as an intermediary is not going to happen on today’s technology. It’s a fact that cannot be overcome by the flashiest of promises.

Even though Teradek’s hardware and software are technically capable of handling all of that data, the iPad that it is reliant on is not. With the new A9X processor coming in the just-announced iPad and iPad Pro, the iPad Air 2 will be outperformed by almost two times. Perhaps then, Teradek’s app will have a fresh shot at bringing us closer to ultimate streaming mobility. Until then, we futurists will have to remain in the present.

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