IPTV@IBC2010 special report
Internet TV viewership continues to grow, both competing with and complementing traditional television services and dedicated-network IPTV. The unpredictable nature of viewers’ network connections and viewing device capabilities are key challenges, however, to ensuring consistent, high-quality Internet TV viewing experiences. Unlike the controlled and tightly managed network conditions associated with ‘walled-garden’ IPTV deployments, the Internet offers no such assurance of consistent bandwidth. Similarly, while IPTV deployments are targeted at specific devices such as set-top boxes with known performance, Internet TV viewers may have a wide range of playback capabilities. Mike Nann, director of marketing and communications at Digital Rapids, reports.
Improving the Internet TV experience
A
daptive streaming technologies set out to solve the problem outlined in the
introduction, enabling higher-quality video with
television-like continuity and reliability on the Web and mobile devices - even under drastically changing network connectivity and playback conditions. Of course, higher-quality experiences mean happier viewers who will stay engaged with the content longer, providing greater monetisation opportunities for the content or service provider. Adaptive bit rate streaming overall is not a new concept; there have been a number of implementations of this concept over the years that have met with mixed commercial or technical success. The latest generation of
Figure 1: Live
adaptive streaming workflow overview.
adaptive streaming technologies such as Microsoft IIS Smooth Streaming and Adobe’s HTTP Dynamic Streaming have significantly raised the interest level and adoption of adaptive streaming while improving the resulting experience for end users. Both of these technologies use the HTTP protocol (the protocol used for Web page delivery), leveraging existing Web infrastructures and caching technologies. While these two technologies get much of the attention, they aren’t the only technologies that are using HTTP to adaptively reach viewers - there are numerous others, as well as adaptive streaming capabilities incorporated within broader service offerings. Much of the initial interest in the latest generation of adaptive streaming technologies focused on enabling
video delivery at HD resolutions over the Web for playback on PCs. We’ll primarily focus on this Internet TV context in this article, and on adaptive streaming technologies based on the HTTP protocol. It’s worth noting, however, that the unpredictable bandwidth of mobile devices means they can benefit as much or more from this technology as PCs. Apple’s HTTP Live Streaming for the iPhone brought adaptive streaming for mobile devices to the forefront, but adaptive bit rate delivery is also available or forthcoming on other mobile platforms from Android to Windows Phone 7. Even on PCs, the interest in adaptive streaming isn’t just about HD. Adaptive streaming can also make standard definition Web experiences more consistent and reliable, of particular interest for content that isn’t produced originally in HD, or in regions where limited bandwidth makes HD bit rates impractical.
Under the hood
At its basic level, adaptive streaming refers to a number of technologies for
S24 l ibe l OFFICIAL GUIDE TO IPTV@IBC2010 september/october 2010 l
www.ibeweb.com
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