Originally featured on BroadcastEngineering.com
MPEG-DASH stars at IBC with first products
The rapid advance of the MPEG-DASH adaptive streaming protocol is evident at IBC this year, with the first demonstration by the EBU (European Broadcasting Union) of its use for playback with the HbbTV 1.5 hybrid TV standard. The annual broadcasting show in Amsterdam also coincides with the arrival of a multiscreen platform supporting MPEG DASH from Thomson Video Networks, which has incorporated it in its ViBE VS7000 platform. This was done using a multimedia player that has MPEG-DASH built in from California-based multimedia software company VisualOn.
Another significant MPEG-DASH demonstration at IBC was a repeat of the world’s first large-scale live public trial of MPEG-DASH staged by Belgian public broadcaster VRT during the London Olympics. This is being shown on the EBU stand featuring a live video stream encoded using the MPEG-DASH ISO Base Media File Format Live Profile, delivered through the CDN of Belgian Telco Belgacom to a range of device categories, including tablets, smartphones and PCs, running iOS, Android and Windows operating systems.
MPEG-DASH (Dynamic Adaptive Streaming over HTTP) now has the backing of just about the whole digital content industry, apart from Apple, as the common streaming protocol for delivering services to multiple screens over the Internet. It does not deliver any dramatic technical advances itself, with the aim being to provide a single platform for OTT and multiscreen services over the Internet, avoiding the need for operators to build several parallel infrastructures to reach all their target devices. As it is, they may still have to support Apple’s HTTP Live Streaming (HLS) to reach iOS devices, but Microsoft has confirmed its support for DASH and has indicated that it will converge its Smooth Streaming towards it. Like HLS, Smooth Streaming and other such protocols such as Adobe’s HTTP Dynamic Streaming, MPEG-DASH works by splitting video content up into several sequences of small chunks each encoded at a different bit rate to accommodate varying network conditions and device capabilities. In the EBU’s HbbTV demonstration, the various devices on show obtain different streams to suit their own resources, highlighting the potential to optimize streams for multiple platforms under MPEG-DASH. This demonstration also exhibits the support under HbbTV with MPEG-DASH for time-shifted viewing.
Beyond all the hype and excitement though, concerns were voiced around the floor at IBC that although MPEG-DASH is building unstoppable momentum, there are still hurdles to be overcome. Some of them concern the standard itself, notably Apple’s attitude given that this threatens to prevent it achieving anywhere near the promised universal reach. Another issue is when and how MPEG-DASH will be integrated with Web browsers and HTML5. One concern here is whether browsers will standardize on a single video codec, or continue down the current twin-track approach, where some support H.264 and others WebM, which is the open royalty-free video compression standard — promoted by Mozilla, Opera, Adobe and Google among others — for use with video played back inside an HTML5 browser. There remains therefore the risk that browsers promoted say by Google support WebM, while Internet Explorer goes with H.264 as that appears to Microsoft’s preferred codec. MPEG-DASH is codec agnostic, but such splintering would mean content distributors would still have to support two versions of streaming to cater for each of the codecs, again diluting the appeal of MPEG-DASH as a single universal standard.
Yet while debates over these issues were ringing in to the night at IBC, the consensus was that MPEG is an important unifying force that even Apple will be forced to acknowledge.