The fifth annual Broadband TV Conference, held June 3-4, 2014, in Santa Clara, CA dealt with many key issues on a variety of subject matter, in commercial free panel sessions and individual presentations. The multi-track conference covered topics such as:
- Is Television As We Know it Sustainable?
- The Future of Second Screen, Augmented TV and TV Apps
- OTT Devices – Is the Dominance of the TV Fading?
- Where is TV Everywhere? Analyzing the Business, The Rollouts, The Hype…and the Reality
- Which Technologies Will Change Television and Connected Viewing?
- The State of Over-the-Top Deployments – What Can We Learn From “WrestleMania”?
- A new Video Streaming Standard and new methods to measure video quality
- Why point-to-point/star topology WiFi (even with IEEE 802.11ac chips) is not suitable for multi-screen viewing in the home/premises
Broadband TV and multi-platform services are now rapidly redefining the television landscape and the industry finds itself on the precipice of a massive shift in value. In particular, on demand over the top (OTT) Internet video on demand (VoD) is being complemented by linear/real time OTT video as well as downloaded/stored videos for later playback.
Some of the mega-trends that are driving the shift are the following:
- Content owners have more choice in distribution (satellite, cable, telco TV, broadband Internet via subscription or add supported)
- Advertisers are targeting consumers in ways never before possible (especially on mobile devices).
- On-demand and binge viewing is rapidly growing in popularity (particularly on smart phones and tablets).
- Original digital content is enabling broadband TV service providers to grow their user base and create ‘stickier’ services.
- The broad reach of social media technologies are giving content owners new ways to interact with audiences and consumers in turn are now able to directly influence the success or failure of programming.
- Streaming video is not only for OTT content on second screens, but also for connected TVs and 4K TVs (which will likely first be used ONLY to view OTT content on demand).
- OTT video streaming quality has markedly improved due to a combination of factors, which include: better video compression (HEVC and the older H.264 MPEG4 AVC), adaptive bit rate streaming (based on HTTP), CDNs (like Akamai’s) and local caching of video content, higher broadband access speeds (both wireless & wire-line).
The highlights of selected sessions are summarized in this multi-part article. Each article will deal with one session. We emphasize technology topics rather than marketing and content distribution issues.
DASH- A New Standard for OTT Video Streaming Delivery, by Will Law of Akamai
The vital importance of this new video streaming standard was emphasized by Will Law of Akamai Technologies during his opening remarks: “DASH intends to be to the Internet world … what MPEG2-TS and NTSC have been to the broadcast world.”
[Note: DASH stands for Dynamic Adaptive Streaming over HTTP]
Video/multi-media streaming over the Internet (from web based video server to streaming client receiving device) was said to be a “feudal landscape.” There are a proliferation of standards and specs, like Adobe Flash (with or without HDS), Apple HSL, HTML5 live streaming, Microsoft’s Smooth Streaming/ Silverlight, MLB.TV’s proprietary streaming methods, etc.
That may now change with DASH, according to Will. It has the potential to harmonize the industry if the major video streaming players converge and adopt it. DASH can support a wide range of end points that receive streaming video in different formats- from 4K TVs to game players, tablets, smart phones, and other mobile devices.
MPEG-DASH is an international standard — ISO/IEC 23009- for the adaptive delivery of segmented content and “Dynamic Adaptive Streaming over HTTP.” Apple was one of many collaborators who worked together under the Motion Picture Experts Group (MPEG) to generate the DASH standard.
There are four components in the DASH standard- ISO/IEC 23009:
- Part 1: Media Presentation Description (MPD) and Segment Formats – Corrigendum completed; 1st Amendment is in progress. MPD is expressed as a XML file.
- Part 2: Conformance and Reference Software (Finished 2nd study of DIS)
- Part 3: Implementation Guidelines (Finished study of PDTR)
- Part 4: Format Independent Segment Encryption and Authentication (FDIS)
The objectives of ISO/IEC 23009 DASH were the following:
- Do only the necessary, avoid the unnecessary
- Re-use what exists in terms of codecs, formats, content protection, protocols and signaling
- Be backward-compatible (as much as possible) to enable deployments aligned with existing proprietary technologies
- Be forward-looking to provide ability to include new codecs, media types, content protection, deployment models (ad insertion, trick modes, etc.) and other relevant (or essential) metadata
- Enable efficient deployments for different use cases (live, VoD, time-shifted, etc.)
- Focus on formats describing functional properties for adaptive streaming, not on protocols or end-to-end systems or implementations
- Enable application standards and proprietary systems to create end-to-end systems based on DASH formats
- Support deployments by conformance and reference software, implementation guidelines, etc.
The scope of the MPEG DASH specification is shown in the illustration below:
There are six profiles defined in ISO/IEC 23009. A profile serves as a set of restrictions on the Media Presentation Segment, which provides information for adaptive streaming of the content by client downloading of media segments from a HTTP server. Different addressing schemes supported include: segment timeline, segment template, and segment base. For more information, see Media presentation description and segment formats for DASH.
The important market benefits of MPEG DASH were said to be:
- Independent ISO standard – not owned by any one company
- Multi-language/multi-format late-binding audio
- Common encryption
- Templated manifests
- Efficient delivery from non-segmented origin files
- Efficient ad insertion (critical for ad supported video’s)
- Industry convergence for streaming delivery
- Vibrant ecosystem of encoders and video/audio player builders
The DASH Industry Forum:
The ISO/IEC MPEG-DASH standard was approved by ISO/IEC in April 2012 – only two years from when work started. After that, leading video/multi-media streaming companies got together to create this industry forum to promote and catalyze the adoption of MPEG-DASH and help transition it from a specification into a real business. The DASH Industry Forum (DASH-IF) grew out of a grassroots DASH Promoters Group and was formally incorporated in September 2012. Today it has 67 members spread throughout the world. Objectives of this forum include:
- Publish interoperability and deployment guidelines
- Promote and catalyze market adoption of MPEG-DASH
- Facilitate interoperability tests
- Collaborate with standard bodies and industry consortia in aligning ongoing DASH standards development and the use of common profiles across industry organizations
A harmonized version of DASH, with pre-selected options, is DASH-AVC/264. Will said it was a common version of DASH that everyone could use. Ongoing work for DASH-AVC/264 includes: multichannel audio, HEVC video, 4K/UHD video, live (linear) streaming, support of various video players, backend interfaces, DRM, and Ad Insertion. There are many MPEG-DASH products today as per the following chart:
A DASH MSE Reference client, delivered as an open source player, is available from Github. Released under the BSD-3 license, it leverages the Media Source Extensions and Encrypted Media Extensions of the W3C. Enabled in Chrome v23+ and IE11+. It is free to use and extend by the app developer.
In summary, Will stated why Akamai likes MPEG-DASH. The key benefits are:
- industry convergence for streaming delivery
- multi-language/multi-format late-binding audio
- common encryption
- templated manifests
- efficient delivery from non-segmented origin files
- adopted by both Microsoft and Adobe as their forward streaming
- efficient ad insertion
- vibrant ecosystem of encoders and player builders
Comment and Analysis:
While Akamai is best known for its Content Delivery Network (CDN) that speeds up the flow of Internet packets (especially video) using its distributed network technologies, the Cambridge, MA-based company has recently been focusing on the booming OTT video industry.
Launched last year, Akamai’s cloud based VoD video transcoding service turns single video files into versions that are suitable for playback on a specific screen/end point client device. Akamai also offers its own cloud based video streaming service – for both live and on-demand videos. One would suspect they’ll use MPEG DASH video streaming (as well as older methods) and encourage other Internet video streaming sources and sinks to do likewise.
“In the old world of streaming, you had one device that content providers were targeting – it was either a PC or a Mac,” said Akamai’s EMEA product manager Stuart Cleary. “Now it’s a much more complex environment for a content provider to get their video out.”
Using a single standard for video streaming -such as MPEG-DASH- would simplfy that environment, although developers would have to choose the correct options for the targeted client/end point TV screen or device. Evidently, Akamai aims to be a major player in the cloud based OTT video delivery market place.
Technologies that will offer higher quality viewing experience & enable new OTT services (includes summary of Will Law’s presentation at 2013 OTTCon – the previous name for BroadbandTV conference)
Time and space constraints do not permit me to highlight all the excellent sessions from this two day conference. Such a complete report is possible under a consulting arrangement. Please contact the author using the form below, if interested: