The Battle for Tiny Bits
This article appears in the February/March issue of Streaming Media magazine.
History, so they say, tends to repeat itself. Yet, it often repeats itself in ways that aren't obvious to present-day participants.
In the past several Sourcebooks, we've covered a series of battles that are shaping the landscape of online video delivery. For instance, last year we
covered the battle of "The Great Land Grab" as multiple armies vied for the same land-set-top box and over-the-top dominance—bringing a strange array of alliances between traditional broadcasters, cable, media syndicates, satellite, and telecoms.
Before we deliver our report from the front, a quick word about war terminology, which Streaming Media's Dan Rayburn rightfully noted is often used too cavalierly. I'm probably as guilty as the next technology journalist of loosely using war terms to describe some basic scrap between two companies. But these rumbles are large enough—and involve so many players—that the "battle" term fits in a way that no other term does. We'll all look back on these battles as defining points in the war for streaming media dominance.
This year we're covering the Battle for Tiny Bits. There are three parts to this ongoing battle: The most obvious direct assault is over the type of bits delivered, but two equally important flanking maneuvers are the battle to control the mobile wireless spectrum and the battle for financial dollars, in both the equities and advertising markets.
The Move Towards MPEG DASH
To say iOS devices are impacting the world of online video would be a gross understatement. For the past 2 years, iOS devices from the handheld media device (iPod touch) to its cellular cousin (iPhone) and the more recent tablet edition (iPad) have defined online video consumption.
The Apple iOS dominates web browsing (52% of all mobile browsing comes from the Safari mobile browser, which is available exclusively on iOS devices) and mobile video consumption (52%, 64%, or 80%, depending on which report you read). It's also clear that mobile media consumption is on the rise in general: Overall media consumption engagement on mobile devices is said to be up to 40% higher than on desktop or laptop PCs.
Given Apple's dominance in the mobile computing world, it's no surprise that the Apple HTTP Live Streaming (HLS) method of adaptive bitrate delivery has become one of several de facto standards and has attracted the attention of competitors.
I say one of several de facto standards because the HLS approach-which uses MPEG-2 transport streams and a proprietary manifest file, which provides details on where to find each of the multiple streams required for adaptive bitrate delivery-has competition from a variety of fragmented MP4 (fMP4) approaches, namely Adobe and Microsoft. Both of these companies also use a proprietary manifest file.
What's interesting about HLS and the two fMP4 approaches is that they have more in common than they often admit (but isn't that the nature of wars, at least when viewed from a distance?). All these approaches use standards-based file container formats (.ts or .mp4), and all use a manifest file of some sort (.m3u8, .f4m, .ismv) to direct the end user's video player to find the appropriate cache location for the video streams. Even where they differ on the size of files—Apple prefers thousands of tiny files while fMP4 prefers to create its segments on-the-fly from a series of consecutive bytes (a byte range)—and the way they parse their manifest files, there's a surprising bit of commonality.
To broker a peace initiative between HLS and the two fMP4 approaches, or at least to better define the landscape, the MPEG standards committee has ratified MPEG DASH as a standardized way of presenting the data in a manifest file (called an MPD or Media Presentation Description) for delivery of dynamic adaptive streaming over HTTP.
DASH was ratified in early December 2011 by 24 national bodies. It is now known as ISO/IEC 23009-1, for those who keep track of ISO standards. More than 50 companies and 90 experts have contributed to the MPEG DASH specification.
At Streaming Media West 2011, during a session titled MPEG DASH: Driving the Growth of Streaming Using the New HTTP Standard, the MPEG DASH Promoter's Group was asked about the impact of DASH on Apple HLS.
"If HLS were perfect, DASH would not exist," said Thierry Fautier, Harmonic's senior director of telco solutions. Another panelist noted that Apple had released an "informational specification" to the Internet Engineering Task Force for its manifest file format (.m3u8) but that the underlying MPEG-2 transport streams used by HLS are standards-based and, therefore, could also be presented in such a way that an MPD that is DASH-compliant would be able to read the segment locations and play them in a DASH-compliant player.
Compliant players are a huge stepping stone for DASH. Now that DASH has been ratified and movement is underway for a common encryption scheme and common file format, there's a huge need to deal with interoperable, DASH-compliant players.
In fact, getting encoded content to consistently play back on every device or platform may be the biggest challenge of all. If DASH can't get to the consistency of Apple HLS playback on iOS devices, there's a question as to whether DASH will provide an alternative to any of the proprietary approaches.
The challenge is as much for Qualcomm, Inc. and Ericsson—both of which have representatives on the MPEG DASH Promoters Group and both of which are intimately involved in the creation of mobile handsets and infrastructure—as it is for Adobe, Microsoft, or any of the software companies that contributed to the draft DASH standard. Like the DVD standardization from years past, DASH is all about the consistency of playback rather than a set requirement on how to encode or decode content.
Related Articles
Acquisitions and mergers in 2011—including Cisco-Inlet, Polycom-Accordent, Akamai-Cotendo, and Thoma Bravo-Telestream—will have a significant impact on the online video landscape in 2012 and beyond.
12 Mar 2012
Companies and Suppliers Mentioned