The New Alphabet

High definition analog technology competes with IP cameras

• By Gary Perlin
• May 01, 2015

Mastering the alphabet used to be as simple as learning your ABCs. Not anymore. A whole new alphabet has been created for the world of analog video. Don’t try to sing this one to the “Alphabet song” we all grew up with. It doesn’t work. Trust me. I just spent 15 minutes trying.

The new alphabet goes CVI TVI AHD SDI SDIv2. Each group represents a high definition analog technology that was created to compete against megapixel IP cameras. This article will not be comparing Analog to IP or addressing the virtues of one over the other, but will explain why high definition analog exists and what the future may hold.

Let’s start by going way back in history to the year 2012, which is ancient history in the world of technology. Analog cameras were hard pressed to put out an honest 700 lines of resolution while IP cameras were easily displaying pictures of 1 and 2 megapixels (720P and 1080P respectively) and up to 5 megapixels in some cases. On the down side, IP cameras were expensive and difficult to install.

This must have seemed like the perfect business opportunity for a group of companies to create megapixel low cost analog solutions to go up against IP. Sadly, it arrived just in time to compete with the new generation of low cost plug-and-play IP equipment. I guess timing really is everything.

Let’s say you’re ready to start that new high resolution project but aren’t sure what to use. Both IP and analog can give your customers a terrific solution, depending on their needs. If for whatever reason you’ve decided to go the HD analog route, the two most popular technologies in analog HD today are CVI and TVI. CVI seems to be bigger in the DIY market whereas TVI is found in more commercial products. Both give excellent picture quality in their 720P and 1080P versions. The specifications of both continue to evolve, but you should expect extended transmission distances on coaxial cable and remote control of key camera functions on most. Another option, AHD, is currently only available in 720P. In my mind, this puts it at a disadvantage. Rumors abound about AHD being available in 1080P, but I have not seen a legitimate working sample yet. Perhaps by mid-year? Right now, AHD is not widely available and has a more restrictive feature set than TVI and CVI.

That leaves SDI and the newer SDIv2. SDI has very few supporters right now and many former SDI supporters are moving to the TVI and CVI bandwagons. You will most likely find SDI products built into other products such as public display monitors.

A few caveats: For your convenience, none of the above technologies work with each other. Each technology requires its own DVR. TVI requires a TVI DVR. CVI requires a CVI DVR, etc. Most of these new HD DVRs will accept signals from your older existing 960H cameras, but from what I have seen, the results are not great. I suggest that you should go all HD or stay with your 960H for now. There are promises from various manufacturers that we will soon be seeing multi-format DVRs that will accept both CVI and TVI. No dates have been given yet.

The pictures from these new HD products are fantastic. Coupled with a cost that is lower than today’s 960H products, HD analog has the ability to change our thinking about analog for years to come. It’s a technology that is here to stay.

This article originally appeared in the May 2015 issue of Security Today.