Latency: The Next Frontier
Video compressions look pretty good these days. From Real to VC-1 to H.264 to VP6/7, innovative compression technologies have coerced remarkable quality out of even the most complex video sequences. With the exception of compressing HD signals into small enough bandwidths to meet the needs of the average broadband user (defined, according to Congress, as having 200Kbps of sustained data throughput), online video has entered the consciousness (and homes) of most of the U.S. population.
Yet one issue remains a consistent thorn in the side of video compression, especially those technologies based on legacy streaming technologies instead of, say, videoconferencing or other two-way technologies. That issue is latency, and has continually limited streaming video’s usefulness when it comes to key applications.
Granted, for most traditional or web broadcasts today, excluding horse races or other games of skill or chance, latency is not an issue: Who cares if the video is delayed by 6 – 10 seconds? But for applications such as mobile videoconferencing, surveillance, or other very time-sensitive delivery of content, latency is a huge issue precisely because it builds upon itself in such a way that it moves from annoying to incapacitating.
If you’re unfamiliar with latency, think of the way that overseas calls used to sound when back in the mid 1980s (or how most online Voice over IP sounds). There was the echo, and there was the excruciating pause where one person had to wait until the other finished before (pause) waiting to speak. If one didn’t wait for the other, the conversation would be fraught with missed words or phrases. It was almost equivalent to today’s cheap speakerphone, but with the requirement to wait a second or two to begin speaking.
Market intelligence firm iSuppli estimates global video surveillance camera revenue will grow from $4.9 billion in 2006 to more than $9 billion in 2011, with unit shipments of video surveillance equipment expected to more than double from 29.8 million in 2006 to 65.7 million in 2011. The market of most interest to StreamingMedia.com readers—that of surveillance-camera chips that would use low latency codecs—is forecasted to reach $1.25 billion by 2011.
Fortunately, as streaming codec providers are beginning to tackle real-time high-definition video encodes—on display in several booths at last month’s InfoComm show in Anaheim—they are also finding that the processing requirements for real-time HD encoding yield the additional horsepower to deliver standard definition encodes much faster than today’s SD-only compression schemes.
It's one of the biggest challenges facing live video streaming today, and it's remained frustratingly stubborn. Explore the technical solutions that could finally bring latency down to the 1-second mark.