Despite the trend towards IPTV and VoIP, most CCTV surveillance cameras are analog. Signals degrade quickly and quality suffers. Until now.
Editor’s note: This blog is sponsored by Pericom Semiconductor.
It’s estimated by Pericom Semiconductor that 80 – 90 percent of the low cost video surveillance market still uses analog video cameras and not digital IPTV. They’re everywhere: from parking garages and street corners, to indoor malls and police cruisers. The cameras keep getting better; their long-distance cable signal quality doesn’t.
New features in analog cameras include stereo audio, in-camera signal pre-conditioning, and much higher resolution images: D1 (720 x 480, NTSC) is 4x better than CIF, and WD1 (wide D1) adds 34 percent more pixels (960 x 480, NTSC). These add up to more information per frame at 30 fps, which means even more data to stuff down long cable runs before termination at the digital video recorder (DVR) receiving end.
But analog cable runs always end up the same way: with lousy, lossy, signals.
Using low-cost COAX in low-budget installations, signals degrade at 1.6dB/100 feet. So in the length of a football field (300 feet), the video at the receiving DVR or security console is getting poor (Figure). 300 feet is pretty short when you consider cables snaked up/down pillars, into attics, or through myriad cable-to-cable noise-injecting connectors.
Ironically, the solution to this signal loss is often to add expensive analog amplifiers at the receiving end—at the cost of $5 – $10 per camera channel. So much for low-cost surveillance. A typical 16-32 camera system tacks on up to $320 in amplifiers. Better quality cables help, but run length is the killer.
Pericom Semiconductor, a company exclusively focused on signal integrity products, includes adaptive equalization (AEQ) algorithms into several digital video and audio/video decoder ICs. The company claims that proprietary adaptive filters improve signals by 2x, translating to either double the picture clarity or decent analog video at twice the usable cable length.
Compared to an analog amplifier, a company spokesman told me, designing in the ICs into a DVR receiver will save tens of dollars per video channel and improve performance. Voila! Clean analog signals over long cable runs on a budget.
So look sharp the next time you spot a video surveillance camera: it’s possible your smiling mug may be more clearly recorded than you think, thanks to the AEQ signal processing available for plain old analog video cameras.