The Promise of H.265

Compression algorithms - both open and proprietary - are trending to ever-greater efficiency

The rise in popularity of 4K and other high resolution security video has increased pressure on standards organizations and vendors to develop compression techniques to address the changing landscape.
The rise in popularity of 4K and other high resolution security video has increased pressure on standards organizations and vendors to develop compression techniques to address the changing landscape.

British statesman Benjamin Disraeli once remarked that “Change is inevitable.” If I didn’t know better, I would have said he was referring to electronic devices of the 21st century. As we are so frequently reminded in this fast-paced industry, we cannot rest on our laurels. We cannot continue designing or proposing physical security solutions based on yesterday’s technology. We have to keep moving forward or we will soon find ourselves left behind.

Video compression technology is a case in point. Advances in video resolution are sweeping through the consumer industry and spilling over into security at an ever-increasing rate. HDTV and megapixel supplanting VGA — and now 4K and beyond — are placing greater demands on system requirements. As a result, standards organizations are feeling increased pressure to develop compression techniques to address the changing landscape. The expectation is that each successive algorithm will provide the same or better image quality at a reduced bit rate, which would decrease storage and bandwidth costs.

H.265 is the most recent compression standard to hit the consumer market, and it has the potential to greatly impact the security industry.

 

Compression: A Brief History

Over the past 18 years, widespread adoption of new video compression standards in physical security products have generally lagged behind their consumer electronics counterparts by four to five years. While H.264 is the most widely deployed recording algorithm in the security industry today, it did not attain that status in the security industry until around 2008. Furthermore, that standard was ratified way back in 2003 by the Moving Pictures Experts Group (MPEG) and the International Standards Organization/International Telecommunications Union (ISO/ITU).

So what took so long for H.264 to become generally available? Repurposing of technology should not take that much time; and in today’s world, that lag time is a luxury we can no longer afford.

Like its older cousin, H.265 — officially known as High efficiency Video Coding (HEVC) — was developed by the ISO/ITU and MPEG. It was formally ratified in April 2013, with a second version added in early 2015. The fact that we are even talking about H.265 at this point deserves a pat on the back for an industry that traditionally is slow to adopt technological change; so, why are we jumping on the “bandwidth wagon” so quickly this time?

 

H.265 Means True Savings

H.265 claims to reduce the bitrate by 50 percent without lowering video quality — that translates into tangible savings for security organizations that have to balance safety and security within fiscal constraints. At the same time, our workforce is getting younger, which translates into more security professionals who are accustomed to quick-cycle advances in technology and will not settle for lengthy delays. They are accustomed to HDTV-quality video on devices as small as a watch. They see no reason to sacrifice image usability when specifying cameras for security.

The promise of H.265 is that we can finally start deploying cameras at higher resolutions, such as 4k, which would otherwise be cost-prohibitive for most of today’s security installations. This, in turn, will enable security professionals to deploy cameras that cover a wider field of view but still deliver the pixels on target for forensic review.

Why aren’t we all deploying H.265-enabled cameras today? For starters, there are still not many hardware options available, despite all the talk from manufacturers. Sure, you can find early adopters who are on the bleeding edge — but your options for recording that video are extremely limited. There are lots of video management systems (VMS) that support H.264, but their wide availability lagged almost a year behind network cameras supporting the algorithm.

Most likely a similar adoption rate will happen with H.265 once major camera manufacturers develop support for it. Without both, your choices are reduced to those early adopter manufacturers locking you into what amounts to a proprietary solution.

There is one more sticky point regarding adoption rates that has to do with litigation. Unlike the license-free H.264, HEVC now brings the specter of licensing royalties with the introduction of the HEVC Advance (www.hevcadvance.com) — an independent licensing administrator company that oversees the pool of more than 500 patents relating to H.265.

 

Zipstream: A New Security-Specific Algorithm

H.264 is likely to be the video standard of choice for the foreseeable future based on the barriers of entry for H.265 mentioned; however, there are still options for reducing bit rates further with the existing algorithms. One such technique comes from Axis Communications, called Zipstream — a radically more efficient implementation of H.264 that can reduce bandwidth and storage requirements by an average of 50 percent or more when compared to existing H.264. Sounds familiar right? That is the same savings figure that HEVC is touting.

What makes Zipstream different is that it is specifically designed for surveillance. The algorithm encompasses two methods for reducing the video bit rate:

  • Dynamic Region of Interest continuously analyzes the video stream for motion. It applies lower compression settings in those areas while simultaneously applying a higher compression ratio on static areas.
  • Dynamic Group of Pictures (GOP) dynamically adjusts the interval between I-frames based on the motion level within the scene. The less motion there is the greater the interval which results in lower bit rates.

These two methods can be used independently of each other, or in combination, to reduce the stream’s bit rate and make the best use of the available bandwidth.

To put this into perspective, security video tends to have long periods of little to no activity. A good example would be a school during off hours or holidays when theft and vandalism are more probable. During off hours, Zipstream would analyze the video for movement. If there was none, it would increase the compression rate and increase the GOP length, drastically reducing the storage requirements of recording an empty hallway.

If someone entered that hallway, the technology would automatically identify the person as a Dynamic Region of Interest and reduce the compression ratio in that region to preserve the forensic value of the recording. Simultaneously, it would reduce the GOP length providing more I-frames to capture any movement in the scene and provide the appropriate level of detail for security professionals to conduct post incident forensic review. In essence, important forensic details such as faces, tattoos and clothing patterns are isolated and preserved, while elements of little interest such as white walls, lawns and vegetation are compressed at a higher rate.

Zipstream fully complies with the H.264 standard and is compatible with all VMS solutions that support H.264 today. The same cannot be said of H.265 which will require VMS manufacturers to develop support for a wholly new compression technique.

 

Zipstream vs. H.265

If security professionals can already achieve 50-percent savings in bandwidth and storage with their existing VMS, is H.265 finished before it even gets to the starting line? Unlikely. It is also unlikely that Zipstream would sideline H.265. Instead, the technology is not intended as a replacement for H.265, but as a video coding enhancement that can augment many video compression standards.

As the market works out the obstacles with licensing and VMS compatibility, manufacturers and customers will begin rolling out H.265 solutions. I would expect that more companies will launch H.265 cameras in 2016, but broad adoption may not occur for another few years. On the other hand, video coding enhancements such as Zipstream, will most likely be applied to whatever compression standard is launched in the future.

 

James Marcella has been a technologist in the security and IT industries for nearly two decades. He is currently the Director of Technical Services for Axis Communications. To request more info about Axis, visit www.securityinfowatch.com/10212966.

 

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