End-users, consultants and specifiers want more choices to assure they are getting the best of breed. Integrators want equipment to work and be plug-and-play. They do not want surprises as they start connecting equipment, which can erode precious margins and their reputation. Manufacturers want to grow.
These possibly over-simplified needs are eternal. They are as true in the past as they will be in the future. They are not new in the world of IP video, as while you could plug an NTSC analog camera into a DVR via coax to see and record video, you were stuck in one fixed position with analog PTZ cameras. Sure, you could view the video, but unless the DVR knew how to control the PTZ camera, you couldn’t move it. The control mechanism, also known as a protocol, was not standardized. Instead, the largest manufacturers each had their own and others started to simply reuse them rather than reinvent them. The bottom line was that if you wanted a PTZ camera and a DVR from two different manufacturers, you had to make sure they could speak the same protocol and then you had to manually set it.
In the world of IP video, there are similar issues with incompatibility. However, there are more severe consequences, because there are a whole host of things that travel between the camera and recorder, including compressed video, audio, camera settings, information about the PTZ’s current position and even information about the scene — such as whether someone is loitering or how fast a car is driving through a parking lot, possibly even its color. This has become possible because the camera is more intelligent and can communicate data.
The video surveillance market has turned its back on proprietary solutions with the creation of at least two bodies, ONVIF and PSIA. The Open Network Video Interface Forum (ONVIF) was founded by Axis, Bosch and Sony back in May 2008, with a clear focus on network video devices. The Physical Security Interoperability Alliance (PSIA) began in the same year with a broader scope that encompassed more areas of security devices. The existence of two competing bodies has driven each to progress faster than is typical and each has had published specifications for some time now.
Technically speaking, both ONVIF and PSIA have created specifications, not standards. To become a true standard like NTSC, a standards body would have to accept it using a rigorous process. But these specifications are the first step towards that ultimate goal.
Compatibility before ONVIF and PSIA
Even before ONVIF and PSIA, there was a work-around to ensure compatibility. The creators of “open” video management software (VMS) that view and record different manufacturers’ cameras have invested huge amounts of effort in integrating and testing each camera using a piece of software glue called a Software Development Kit (SDK) that comes from the manufacturers. SDKs are available for most things, including IP cameras, encoders, DVRs, network video recorders and even video management systems themselves. SDKs allow you to squeeze out every differentiated feature from a device, but also require a huge amount of up-front and maintenance effort.
Now that we have a better understanding about current SDKs, let’s take a closer look at one of the standards candidates, ONVIF, so we can investigate what it means to the marketplace (see PSIA Executive Director Dave Bunzel’s sidebar on his organization, page 26).
ONVIF has created a specification which is simply documents that define how networked entities (let’s keep it simple and assume an IP camera and a VMS), can communicate and understand each other’s capabilities. The classic analogy is ONVIF specifies a common language, say English, so that these entities can speak to each other. They depend on this common language to exchange all kinds of information to reach conclusions such as “Shall we use H.264, MPEG-4 or JPEG — what would you prefer?”, “Do you mind setting your current time to 10:35 a.m.?” or “Would you kindly jump to preset 8?”