As described by Kevin Towes, senior product manager for Adobe Flash Media Server, the firm is planning to streamline the workflow for live broadcasts in Flash by enabling distribution to devices that employ Apple’s HTTP Live Streaming (HLS). While the Adobe Hypertext Transfer Protocol-based adaptive streaming system known as HTTP Dynamic Streaming (HDS) and HLS both use H.264 encoding, the incompatibility occurs because HLS employs the MPEG2 Transport Stream file container and HDS uses MPEG4-fragments (F4F) to encapsulate the video “chunks” or segments of a file that are delivered at various bit rates by adaptive streaming mechanisms.
Adobe offered a preview of the expanded capabilities at the NAB Show in April. “The biggest story I’ve seen at NAB is the ability to transition from thinking of Flash as a Web delivery platform to a broadcast platform – a broadcast platform with multiple different screen types that include Flash and some that don’t include Flash,” Towes said. “And so our job is to try to make it as easy as possible for content publishes and broadcasters to really make the money at video, delivering video, lowering their workflow costs and really reaching the audience on whatever screen they want to.”
“The sneak peak we’re showing here at the show is our first innovations around live,” he added. “It’s really a nice thing to show that single workflow, and something we continue to invest in is simplifying the workflow for publishers no matter what kind of content they have.”
Towes stressed the emphasis right now is on supporting multiple stream modes for live broadcast. “We’ve not made any announcements around video on demand packaging for HLS or Apple streaming,” he said. “What we’re showing here is how a vision of a workflow could be with a single live stream.”
Pressed on the fact that, having done it for live, Adobe could apply the same technology to making Web-based Flash content delivered via HDS compatible with HLS, Towes replied, “We’ve not made any announcements around video on demand packaging for HLS or Apple streaming. What we’re showing here is how a vision of a workflow could be with a single live stream.”
Adobe’s move comes amid an industry-wide push for greater interoperability in the distribution of video across all types of devices. Most notably, the ISO is spearheading DASH (Dynamic Adaptive Streaming over HTTP) as a nascent standard that has now reached committee draft status for purposes of systematizing an approach to H.264-based adaptive streaming that works with both the MPEG2 TS and the F4F container formats. Here the emphasis has been on overcoming the incompatibilities between HLS and Microsoft’s Smooth, which, like Adobe’s HDS, uses F4F. But, so far at least, the nuances that distinguish HDS from either of the other two dominant streaming modes remain outside the scope of the DASH initiative.
At the same time, despite the trend toward harmonization, there’s a move in the opposite direction driven by Google with its embrace of an alternative codec to H.264 in what is known as the WebM initiative. Last year Google acquired encoding technology supplier On2 and now has made that entity’s latest codec, VP8, available on an open-source basis, which will allow developers to avoid the royalty payments required with use of H.264.
While YouTube continues to use Flash, in both the earlier iterations that employ VP2 compression supplied by On2 and more recent versions using H.264, Google says it will no longer support H.264 in its Chrome browser. Along with VP8 for video, WebM employs another open-source codec, Vorbis, for audio.
While Google’s move may be disruptive to peace and harmony in Web video publishing, the WebM initiative is very much in stride with the diversity that has make the Internet a fountainhead for innovation. As such it is welcomed in many quarters, although questions have been raised as to whether Google can deliver on its promise that VP8 will be royalty free, given the range of entities with intellectual property claims on virtually any type of compression.
Adobe, for one, welcomes the WebM initiative. “We’re excited about WebM,” Towes said. “The spirit of open source means that you’re going to have more devices, more technologies able to encode, capture, decode and render video using different formats.”
H.264 is clearly the standard that dominates, he noted. “When your mobile phone or your tablet is accessing video, that’s really where the hardware decoding needs to happen,” he said.
But supporting multiple codecs is already a given with Adobe, he added. “Adobe continues to support a broad variety of video codecs like VP6, Sorensen and H.264 and is committed to supporting VP8 in a future version of Flash Player, to ensure consistent playback of rich content across platforms, Web browsers and devices,” he said.
Asked whether he sees momentum building around WebM, he replied, “Absolutely. I think even Google’s announcement with Chrome to focus on WebM and not H.264 is a signal that Google is very interested in driving that open-source platform. And Adobe is right there with them. Flash is running on the Google Android devices, and we feel very strong about the open-source community.”
But that doesn’t mean it will be a simple matter of tweaking software to accommodate VP8 and Vorbis. Asked how big a deal it will be to get WebM into devices, Towes said, “It’s absolutely a big deal. It’s a big deal when we start seeing video played on tablets, and mobile phones and iPads and TVs.
“It’s funny,” he continued. “The bigger the screen, the less power in the screen. We have a 46-inch Samsung TV here that does not have a lot of CPU power. So the only way you’re going to render a 1080p video is through hardware. Today, Flash Player takes advantage of hardware acceleration to deliver smooth, efficient playback of HD video. For WebM to be successful on mobile devices, I think hardware decoding will be very important.”
That said, it’s clear the trend toward overcoming disparities across streaming modes promises to ease the costs and hassles of IP-based video operations in the future. For providers who look on use of IP technology as the key to enabling revenue-driving services in the managed as well as unmanaged domains, this is good news.