IBC: An all-adaptive bit rate world is realistic, says RGB Networks
RGB Networks believes all video delivery will migrate to adaptive bit rate streaming (ABR), which is a particular approach to IP video where content is encoded at multiple bit rates and resolutions and then split into very short chunks, allowing the client device to decide every few seconds which is the best ‘profile’ the local network can handle, and so adjust the picture quality to match available bandwidth rather than risk picture freezes. The implication is that all video delivery will converge around IP, which most of the industry accepts will happen over time. But RGB Networks is one of a few companies bold enough to declare at this point that all video delivery will also converge around a particular flavour of IP delivery that was developed primarily to meet the needs of unmanaged OTT services (including to smartphones and tablets).
At IBC the company was demonstrating multi-screen TV services delivered by Swisscom Broadcast including adaptive bit rate video to the set-top box. RGB Networks provides multi-screen and advertising insertion solutions designed to enable a unified headend for services targeting set-top boxes, connected TVs, game consoles, smartphones and tablets, etc. It is convinced that beyond physical and logical convergence of video services, Pay TV operators can further rationalise their delivery infrastructure by using ABR more widely.
“People are already talking about it [ABR for all video] and it is happening,” declares Ramin Farassat, Vice President, Product Marketing and Business Development at RGB Networks. “We have two customers today who are doing exactly this in trials. They already have cable or telco services and they want to migrate them. This is for real-time linear content. It is even easier to do for VOD. Linear has always been the challenge but now people are actually doing that.”
Farassat says the next generation of CE devices will support ABR, while there are a number of new set-top boxes that support adaptive bit rate streaming and which cost less than traditional set-top boxes. These new devices will not be confined to the role of IP thin client for second and third room viewing in a whole-home architecture; the expectation is that they will be used as the main home receive device, he stresses. “They are lower cost because the technology has improved considerably. The older STBs have a complex architecture and have to do more. The new STBs are very straightforward with IP input, no demodulators and decryption through standard DRM,” he explains.
The ABR video to the set-top box does not have to be unmanaged over-the-top delivery, of course. As Farassat points out, a service provider could guarantee the bit rate available for an ABR service to the STB so there is always a minimum of 3Mbps available, for example. This is an approach you would expect if Pay TV providers decide to use adaptive streaming for their on-net video offer. The same content delivered to other devices like smartphones, going off-net and via the open Internet, might not be given any QoS guarantees. This dual approach gives subscribers high quality video at home and content everywhere, yet also means the operator can use the same selection of 4-8 bit rate/resolution profiles for programming whether it is destined for the set-top box or a smartphone.
The development of the MPEG DASH standard is closely tied to the desire to rationalise video delivery. This aims to eventually replace the many different types of adaptive bit rate streaming (e.g. Apple HTTP Live Streaming, Adobe HTTP Dynamic Streaming and Microsoft Smooth Streaming, etc.) with a single format. While the initial benefits would be for multi-screen TV services, a standard would also increase the likelihood that ABR becomes the defacto way to deliver all video in future. Assuming MPEG DASH was supported on set-top boxes and CE devices, the ultimate prize could be the ability to encode the same programme in, say, eight DASH profiles for all managed and unmanaged services from smartphone to widescreen HDTV.
The RGB demonstration showed a live video feed into an AirTies ABR set-top box (harnessing Apple HLS). If an RGB customer does want to migrate over time, this is simple using the company’s chassis-based Video Multiprocessing Gateway (VMG) and TransAct Packager multi-screen headend solutions. With all the necessary encoding, transcoding and packaging supported, they can turn off an MPEG-2 license (for example) and turn on an ABR license as required. An all-ABR strategy should be a consideration even now for a service provider launching a Greenfield service.
Farrasat makes the separate point that even in the adaptive bit rate environment, video quality still matters. He emphasises that while ABR adjusts dynamically to the bandwidth available, and provides a gentle progression from one bit rate to another if less or more network capacity is available, you still want to maximise the quality of the video in each bit rate/resolution option. “Some of our customers today launch their multi-device offers with a starting bit rate of 750Kbps and a top bit rate of 5Mbps, with anything from four to eight different resolutions in total. We provide the best quality encode we can for each of those resolutions,” he adds.
John Moulding joined Videonet as editor at the start of 2010, having spent over 10 years writing about digital TV and the various technologies that have simultaneously disrupted and enriched the television business. With Videonet he is focused on the unstoppable march towards multi-screen, connected and personalized television. John was launch editor at Cable & Satellite International (now CSI), where he spent six years, before helping launch New Video Technology, and helped develop the IPTV World Series (IPTV World Forum, etc.) conference programmes from 2006-07. At home, he takes a Sky triple-play bundle, watches around one-third of content time-shifted, but is generally still happy to turn on the TV and see what's on (he can also remember when TV shut down after lunch!).
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