Video: How to Deliver True Live OTT
In this follow-up to What Are the Challenges of Live OTT?, Net Insight's Per Lindgren discusses what content owners in different verticals (and their viewers) are looking for in their live OTT experiences, and what it takes to meet those expectations.
Learn more about live OTT at Streaming Media East.
Read the complete transcript of this clip:
Per Lindgren: We started talking to a number of our existing clients--operators, TV companies, and production companies--about the problems they had experienced with live OTT delivery. The most obvious, of course, was the low delay but after talking to many of them they actually said, "We could work with some delay, but it’s very important for us is that everyone will see it at the same time."
Of course, you have certain applications when you are actually at the event, and you want to watch on your mobile device, you need to have very low delay. And if you’re in the betting industry, the lowest possible delay is of the highest importance. But when we talk to broadcasters and TV media companies, they said, "What we want is a seamless TV experience. If you can provide the same delays that we experience on the normal platforms, the primary screen, that would be the perfect fit."
Also, clients offering premium experiences talked about the channel swap times, like in the early IPTV days--actually, it's even worse on the OTT side, where it can take 2-9 seconds to swap between channels. They all said, “We want picture-in-picture in the same screen,” so the synchronization is very important. We can't have them unsynchronized, and of course we want to have a very resilient stream.
But very many times you also come back to the fast channel change times, not just for the linear service, because they also said, “What we want to do is have multi-camera experiences, with different camera angles. People should be their own producers; they should be able to choose their own content.” If you're adding the ability to switch between camera angles, you need very fast channel swap times; that can't take multiple seconds. So they said, "The perfect thing would be if we could use these mobile devices as a kind of remote control so you work with them but when you come down and sit at home on the sofa you cast it up to the set-top box."
To have that fast, seamless casting, not only to Roku or an Apple TV box but actually to the existing set-top boxes would be really nice. Then you can add a lot of things into the apps like the curation recommendations.
To reduce, delays you have to both look at the client and the segment buffering, but also at the packager. So, when we're doing the most optimized streaming, we actually take away the segmentation and work directly on the stream. Then a lot of people say, "Well that sounds really good, but how can you then do the ABR profiles and work between the ABR profiles?" It works quite well. It's no problem at all to go between different ABR profiles on a streaming service without segmenting the streams. Now we are down to 1.5 seconds with full ABR support.
We also make sure that all devices have the same clocks and show the content at the same time. So, in essence, you get full frame synchronization between all devices. That requires that you also have a notion of time at the devices. The typical time protocol today would be MTP. People start talking about PTP and IEEE 1588. That's something we also add to this, that you have the notion of time and you tell when devices are to show the content. This way we can make sure that everyone watches at the same time.
We work with something we call stateful ABR, so that when you are watching a channel on the device, we know what ABR quality that device is capable of handling. The normal thing when changing to another channel is you go down to the lowest quality and you work your way up again. That can be quite annoying when you're switching fast between channels. So we keep the notion of what ABR quality we are at, and you go down one level instead of going down from the start and restart from again. That not only gives us fast channel swap times, but maintains the quality when swapping between the channels.
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