What is H.264, and Why is it Important in CCTV?

On the subject of DVRs, I’ve often been asked what H.264 means and why it’s important.  Basically, H.264 is currently the best format for compressing video, and is used on a variety of popular technologies, from Blu-Ray to YouTube.  The ability of a security DVR to be able to compress video is not only important, it is essential.

Think of the common file types that are used universally – WMV, MPEG, and AVI. A friend sends a video file to you, you right click onthe image, select properties, and then you see the image’s file type. Those file types each have their own properties or video compression type. Now, consider the size of that image or file, and how much space it may consume on the hard drive. You can then fathom why it’s important to have the ability to compress that video file in order to save space. It’s also important, especially with video surveillance, that with this compression, the quality of the video footage is not decreased.

The intention of H.264 is to establish an acceptable balance between viewing quality and the size of the video file, so that the maximum amount of video can be stored on a hard drive without losing the detail and quality of the video. When speaking of a DVR and CCTV footage, H.264 is imperative not only because of the larger quantities of actual footage (that can span from a few hours to several weeks), but also due to the various purposes for surveillance. Depending on the application, such as a government facility or a retail store that is trying to monitor theft, achieving the highest possible frame rate is essential to identify problems accurately. It is best to stay above at or above a 15 FPS frame rate because once you drop below that, the footage becomes choppy and isn’t nearly as reliable.

H.264 DVRs aid in these endeavors because compressing the video allows for maximum storage on the hard drive, while producing the highest resolution and frame rate capable of the unit and cameras being used. The two main types of video compression for CCTV are H.264 and MPEG/MJPEG.  H.264 is the latest technology in codecs, and will drastically reduce both the bandwidth and storage requirements of video files while still maintaining high-quality images.

Choose HDMI on Standalone DVRs

There are many benefits to having a surveillance system featuring a standalone (analog) DVR. For one, it gives you the power to remotely view your cameras from anywhere in the world via PCs or smartphone devices. And with the ability to add more hard drives, longer viewing times are easily accomplished. Plus, the normal way of viewing cameras through a standalone DVR is ever-evolving as well.

In the past, viewing your cameras may have been accomplished by using a standard CRT television monitor. However, LCD screens have started to become more commonplace as a way of viewing CCTV camera footage, as they offer the benefit of achieving a high-resolution picture with a low-profile body. This has usually been accomplished through a VGA output. But with high definition televisions and high-def cameras becoming more and more popular, we’re beginning to see an increase in HDMI outputs on DVRs.

HDMI supports standard, enhanced, or HD video, plus multi-channel digital audio. Because HDMI was designed specifically for consumer electronics applications, it offers an array of additional enhancements. Standalone DVRs with HDMI will allow you to view your security cameras via a high-definition TV in true HD, so I’m sure you can just imagine the benefit of having a standalone DVR with HDMI output. With HDMI, it’s now completely possible to integrate your home security system into your home theatre system with the same crisp image as if you were watching high definition television.

If you are in the security market, and looking for a major enhancement amongst standalone DVRs, I highly recommend you try one with HDMI; you’ll see why it’s soon to be the future of video output.

Benefits of Progressive Scan vs Interlaced

As camera technology evolves, and better & greater features are accrued, the term Progressive Scan seems to pop up more and more. While some features are easy to identify by name, Progressive Scan remains a mystery to many.

As modern consumers with much experience purchasing TVs, I think most people understand the basic way that pictures are displayed on a TV or monitor screen. There are a certain number of lines that are displayed on the screen, and the order that the lines are tossed onto the screen is how Progressive Scan can be described. There are really only two ways this is done: Interlaced and Non-Interlaced (aka Progressive Scan).

Interlaced Scanning has become the old way of transmitting video. Let’s assume that there are 700 TV lines that are displayed on the screen. With this sort of scanning, all the odd lines are drawn and then the even lines are drawn, then all the odd lines are refreshed, then the even lines refreshed, and back and forth alternately. Can you imagine watching the ball thrown in a football game on TV with this sort of display going on? Although the lines are refreshed very quickly, you can tell by the truck in the picture below that the picture displays very fuzzy.

With Progressive Scan (or Non-Interlaced Scanning), the TV lines are drawn and refreshed in sequence. When the lines are drawn on sequence, whether 1 to 700 or 700 to 1, it not only displays moving objects better, but also decreases the bandwidth used.

By the picture below, it seems that seeing the term Progressive Scan is definitely a perk worth looking for.