The State of MPEG-DASH Deployment
Despite this problem with iOS, there are several LTE Broadcast experiments underway like Verizon’s in the U.S. (which was visible during the Super Bowl) or Telstra’s in Australia, and after a first deployment by KT in South Korea in late 2013 with BuyDRM and Samsung, we shall see several large commercial deployments this year on all continents.
“There are at least eight operators’ trials running right now, and as we go through this year you will hear more and more operators seeing the advantage of LTE Broadcast to add revenue streams and more efficient use of their networks,” says David Price, vice president of business development at Ericsson. “We still have to finalize some aspects of the LTE Broadcast DASH profile—we should expect the DASH-IF to take the lead in that space—and after that there will be no more factors that could possibly deter operators from deploying the solution.”
What About Apple?
In a different market segment, adoption of DASH by pay TV operators is slow, according to Lionel Bringuier, product manager at Elemental Technologies. “In two years nothing has moved in terms of commercial deployments in this field, seen from our window,” he says. “What has changed is the number of labs: all U.S. pay TV operators have DASH in lab now. There is a huge traction in the U.S. But conversion of lab DASH to production DASH takes a long time.”
Almost all interviewees agreed that the lack of native DASH support on mobile devices has hindered the broadcasters’ deployments. While this is changing with the Android 4.4 Media Framework, the Apple world remains focused on HLS—and this is flagged as the number one factor slowing DASH adoption.
“DASH takes so much time to be supported natively on devices that today we can see people try to hack HLS to support HEVC,” Bringuier says. “But it's a problem as it not described in the norm and the day Apple decides to do it differently...,” he trailed off, implying that we could end up in the same chaotic situation that crippled PlayReady’s interoperability on HLS.
Assuming Apple pushes ahead with HLS and doesn’t move to DASH, Netflix’s Mark Watson says iOS device users could see a drop in quality of service. “The really important thing is the cache efficiency: the files which are popular are pushed right to the edge of the network, close to the user, so the bigger the population using one set of files, the more efficient that is,” Watson says. “And eventually we'll get to the state where the only files on the edge caches are the DASH format ones. There might be other format files in the system but they will end up not on the edge caches but rather more on the central caches. If HLS traffic is a small fraction of the overall traffic and still using a separate format, that format doesn't make its way to the edge caches. And if that files are not on the edge caches, then the quality of experience that the users of these devices will get will not be as good.” When asked for their official position on DASH, Apple also refused to comment.
From a wider perspective, the lack of an accessible solution to develop players is clearly a problem, and the open-source dash.js project supported by DASH-IF is starting to solve it, at least for HTML5 (combined with MSE and EME) use cases.
Will Law, chairman of the promotion working group for DASH-IF, calls for volunteers to strengthen the project: “In March we released the live support in dash.js. This player allows the common person to do quite sophisticated adaptive delivery for live and VOD, and in the future for ad insertion. It is crucial for the industry, and we want more industry participation, we need more full time people on it. There is a really great case to do media differently this time around [now] that we have this open source player that can really be a stable and production-ready playback vehicle.”
Other companies are also working on compatible playback solutions. For example, Ashley Still, Adobe’s director of internet video product and experience, confirms the company’s interest in DASH.
“We think that DASH is a natural evolution point for customers who are on HTTP Dynamic Streaming (HDS) today, but we have no plans to end of life anything, neither RTMP nor HDS,” she says. “But certainly we see DASH as a great promise of support across many different platforms.”
“Right now our plans are to implement DASH only into Primetime players,” says Rick Wisher, product manager for Adobe Primetime. “It won't be available in the mainstream Flash player. DASH is additive for Primetime. As we start to add DASH we're not taking away support for other streaming formats. The implementation schedule takes us sometime in Q3 where we will have DASH cross-platform availability with the use cases we support today; definitely this year. In terms or supported profiles, so far we have been looking at the DASH-264 spec from the DASH-IF, but we will also be working with our customers to figure out what their needs are as well. In the future as it becomes widely adopted we will also support DASH-265, as we want to support to UltraHD and the highest encryption standards.” Adobe currently supports CENC in Access DRM, and Still confirms that will be the case with DASH.
The recent release of castLabs’s Dash.as open-source OSMF extension also provides a very interesting option to leverage the mainstream Flash Player installed base, for example as a fallback solution for browsers not compatible with MSE, and have DASH play everywhere on the desktop—at least for free-to-air content. For premium content, castLabs/DRMtoday and Unified Streaming are also bringing up an alternative to Primetime with Access DRM-protected DASH streams playing in a mainstream Flash Player. Time will tell if Adobe tolerates such a competition in Primetime’s yard.
Microsoft is also working very actively in the DASH player area through a combination of initiatives aimed at making DASH available everywhere, with support for PlayReady wherever possible. "Smooth Streaming SDKs and porting kits enable DASH playback on XBox, Windows Phone, and most Windows and Mac platforms,” says Kilroy Hughes, senior digital media architect at Windows Azure Media Services. “The Smooth Streaming Porting Kit can be used for Smooth and now DASH streaming on TVs, set-top boxes, disc players, and other devices. Internet Explorer 11 and other current browsers (such as Chrome) that support W3C Media Source APIs (MSE) on Windows 8, Android, etc., provide DASH playback in a web page using DASH.js or similar script. A Flash OSMF plugin is available for simple applications that run on most legacy browsers. It supports time addressing of DASH Segments, but not DRM.” At the time of this article’s writing in early March, Hughes said Microsoft “can’t speculate on deployment dates for XBox and WinPhone in advance.”
Microsoft is working actively to make DASH available on all devices, with support for PlayReady DRM wherever possible. This table shows the current interoperability status for DASH, Smooth Streaming, and PlayReady.
This methodical work on DASH players is done to provide a seamless support of Azure Media Services DASH streams on the maximum of platforms. But it also reflects Microsoft’s priorities for the move towards DASH: the absolute respect of standards and the quest for interoperability.
“Azure Media servers produce a DASH ISO Media Live Profile that conforms to DASH Industry Forum guidelines and UltraViolet Common File Format, optionally including MPEG Common Encryption,” Hughes says. “These media segments and MPD manifests are expected to be compliant with specifications in DLNA, DTG, DVB, EBU, HbbTV, and other organizations defining interoperable DASH application formats and players.”
Regarding formats strategy, Microsoft is very clear: The transition to DASH is irreversible. "DASH will be the preferred format moving forward,” Hughes says. “Smooth, HLS, and DASH will all be supported to various degrees. A gradual transition to DASH is likely, but that decision will be made mainly by services and content providers adopting DASH." But it's definitely a smooth transition: "Smooth Streaming will be supported as long as there is customer demand; no end of life date is being considered.”
There are many other commercial players available on the market, but their cost, added to the cost of the overall migration to DASH and workflow transformation, is often too high for existing H.264-based services. This is why some vendors are providing DASH playback solutions as part of their product/service offering—like Intertrust, with its Marlin SDK and ExpressPlay client.
“We have seen in the last two years that it was a missing piece in the puzzle for many clients,” says Boccon-Gibod.
Two presenters at the Streaming Forum conference go deep with MPEG-DASH and show how to provide viewers with a TV-quality experience.
The promising format is already splintering. Cisco, Akamai, the BBC, and Qualcomm offer hope for a standardized, unified approach.
At NAB earlier this month, the DASH Talks delved deep into the ways that the standard calls for conformance and allows services like HbbTV to move forward
With the rise of MPEG-DASH and the NAB-related announcements from both Microsoft and Adobe on the topic, we sat down with both companies to discuss the status of DASH support as well as their legacy ABR protocols, Smooth Streaming and HDS
As DASH begins to find adoption, it's useful to take a look back at the development of the standard, as well as to try and determine the issues that will shape the future
Companies and Suppliers Mentioned