Adaptive Streaming: Cloud, Gateway, or Both?
by Leslie Ellis // October 31 2011
Here’s a good one from reader Jan: “Where does adaptive streaming happen – in the cloud, or in the gateway?”
Adaptive streaming is the process of slicing a digital video file into different sizes: Maybe one that’s two seconds in length, another that’s four seconds, and so on. The technique necessarily works hand-in-hand with “trans-coding” and “trans-rating,” which match available bandwidth with video stream size. Less bandwidth, stream the smaller file; more bandwidth, stream the bigger file.
One glance at least week’s TelcoTV event in New Orleans shows a vendor community that is teeming with adaptive streaming. (And teaming, for that matter — vendors RGB Inc., itaas Inc. and Verimatrix announced plans to jointly provide a multi-vendor adaptive streaming option for operators.)
Why: When one is bandwidth-constrained, which can happen when squishing a linear, multichannel HDTV product over DSL networks, it’s good to have adaptive streaming at hand.
Which isn’t to say that adaptive streaming is just an AT&T thing. It’s attractive to anybody with a network that’s staggering under that pesky 45% growth rate of video, as a percentage of IP traffic. That means cable, mobile, and telco networks.
Which brings us back to you, Jan. Where does adaptive streaming happen, gateway or cloud? The answer is … yes. Turns out, parts of adaptive streaming can happen in both places.
Some cable technologists say the headend is the place to right-size streams to suit the care-and-feeding requirements of the end displays – tablets, PCs, laptops, things that connect through the cable modem, not the set-top box. Slice, authenticate, and secure video streams there.
It’s all very Scotty McNealy, who put Sun Microsystems on the map in the late 1980s with this famous remark: “The network is the computer.” (Which brings to mind the one about how the difference between early and wrong is indistinguishable.)
Other technologists submit that the gateway or “hybrid box” (half cable modem, half set-top box) could be the place to do transcoding. In that case, it’s not so much about sizing the stream for the screen, based on available bandwidth. It’s more about making it so that any of your screens can play any of your digital video archives.
Maybe some titles you own were compressed with the older stuff of MPEG-2. Maybe some of your screens only know how to decompress the newer stuff of MPEG-4/H.264, or vice versa. That’s when you’d consider putting transcoding activities there.
Plus, silicon is simultaneously growing in capabilities, while shrinking in size. The gates on the chips are there (or will be), to support the heavy processing requirements of trans-coding.
Which is good, because there’s an h.265 compression method on the drawing boards, and the 2012 Consumer Electronics Show is likely to show fresh examples of “4K” video – the next size up in picture resolution, from today’s 1080p HDTV.
Anyway: Gateway or cloud? Yes. Both. So far.
This column originally appeared in the Platforms section of Multichannel News.