Ian Johnston, Chief Technology Officer, IQinVision
Now that megapixel camera technology has become mainstream in most major markets around the world, there are a number of questions I’m asked on a regular basis in terms of how the technology functions and what’s next for megapixel. I’ve summarised some of the more prominent questions below and provided some answers for those considering IP and megapixel technology.
Megapixel cameras require efficient compression. How do different H.264 profiles perform?
It takes a fair amount of compute power to both encode and decode H.264, so various profiles were created to allow the content creator to trade video quality for bandwidth efficiency. Constrained Baseline is easier to decode, but image quality is significantly lower for the same bandwidth (compared to other profiles). Our company uses Main profile since it is gives the highest quality video for less bandwidth.
Another profile that is more common with consumer devices (i.e. blueray) is High profile. It is designed to be used for movies and doesn’t lend itself well for live security video. It also requires the most compute power to both encode and decode.
Is there still room for M-JPEG and if so, in what applications?
Motion JPEG is somewhat like the cockroach of the industry: it isn’t very pretty, but it’s very good at what it does.
As the number of frames per second drops below 10 fps, H.264 becomes less efficient for storage and starts to approach MJPEG. For anything less than 5 fps, I would recommend using MJPEG compression.
H.264 is also more geared to linear viewing of the video (watching a video clip from start to finish). As such, fast forwarding, rewinding or jumping to a random point in the video is fairly cumbersome with H.264. MJPEG doesn’t have any of these issues since each frame of video is recorded individually.
Another issue for H.264 vs. MJPEG is storage costs. To reduce the size of the H.264 video over time, you essentially have to transcode the video. This takes a LOT of horsepower and time. With MJPEG, it is significantly easier to trim video, and therefore storage needs, after the fact.
What installation considerations are there for megapixel cameras?
Often using IP megapixel technology actually reduces overall bandwidth requirements for a particular site. IP cameras are much more flexible and can be configured with a lot more precision to ensure less wasted bandwidth. For example, a single 5MP camera with a wide angle lens can capture a parking lot with the same detail as several analog cameras, and you can crop an IP camera to not to record the sky or the immediate foreground—areas you most likely don’t care about.
Megapixel does require a more educated installer to appropriately design and install these systems, but that trend is inevitable. Like all transitions, there is an opportunity for smaller integration/installer companies to steal market share from the larger, less nimble firms still firmly entrenched in analog technology.
Large-scale sites already have the required network infrastructure in place. You can scale a system easily if all the information travels over the same Ethernet cables. With an IP-centric design, security video, VOIP telephone calls, physical access control systems as well as their conventional LAN data traffic are all combined on the same network.
How do megapixel cameras integrate with third-party devices, such as access control or intrusion, and how do competing standards from ONVIF and PSIA relate here?
Having all the systems on the same network is a great first step toward interoperability. There is now a significant amount of integration between all the security devices, but more needs to be done to drive true interoperability specifications. It’s still the “wild west” for IP devices and the various protocols in use, but that will change as the market demands it.
Most devices coming onto the market now have basic support for either ONVIF and/or PSIA. In the coming years, a winner will naturally emerge, but for now having 2 specs is much preferred to having 50.
As the migration from analog to IP creates greater competition, what’s next for megapixel cameras?
Top manufacturers will continue to innovate and incorporate other devices into IP megapixel devices. Modern megapixel IP cameras are powerful computers and are now capable of storing video locally and/or hosting applications from other vendors. This is just the beginning, and these devices will follow in the footsteps of another powerful computer—the smart phone.
Think about the iPhone. It completely changed the game and could do things that no other “smart” cell phone could even think of. Apple then created their App store for everyone to create their own applications. The same is happening in the IP camera space now. We’re opening up the camera to our partners to be able to put their application code directly in the camera. As an application marketplace evolves for the security industry, many exciting possibilities will soon appear on the horizon.
