How Recording Resolution Effects a DVR's Frames per Second
Filed under: CCTV Articles, CCTV Security DVR Cards, Security DVR
There are a lot of variables that affect what you see on the monitor when viewing video playback files from a CCTV security camera system. Frames per second (FPS) are usually one of the first and main considerations when making a system purchase, but there are a few things you should know before running out and buying a surveillance system that simply boasts “30FPS!”.
Frame rate is defined by how many still images per second are being displayed, and affects how smooth a video appears. If you have a low frame rate of say 7 FPS, you are going to see images that appear to jerk through motion. In some cases, this slightly jerky video is acceptable, but, if you are going for maximum clarity and detail, it may not be. As the FPS increases, so does the smoothness of the video. The maximum FPS you are going to see in the surveillance industry is 30 FPS, which is about the same number that the human eye can register. Most people will not be able to tell the difference in 30 and 15 FPS, though, because they both produce relatively smooth video. Check out our FPS Comparison Video for a side-by-side comparison of 3, 8, 15 and 30 frames per second.
On most digital video recorder (DVR) systems, whenever you pump up one setting, you are going to lose something in another area. DVRs that advertise 30 FPS per channel are basing that figure on a set image size. For instance, if you get a GeoVision GV800 card that has 30 FPS per channel, that number is based on an image size of 320×240 pixels. On that Geo card, if you increase the recording resolution from 320×240 pixels to 640×480 pixels, your FPS per channel will drop by about half. You would then be viewing recorded video at about 15 FPS. If you increase the resolution again, to 720×480 pixels, the FPS will drop again by about half, leaving you with about 7 FPS, which may be undesirable.
Some of the newer, high end DVR cards are now using hardware to compensate for the loss of frame rate when increasing image size. These are not, however, inexpensive systems. The GeoVision GV-1480A capture card, for example, will allow you to increase the image size to 720×480 and lose only 1 or 2 FPS.
The technology is continuing to advance, and hopefully we will see more affordable, real time recording solutions in the near future. Until then, you have to look at your application, determine what level of detail and clarity you need, and go from there. Remember to always check the maximum FPS per channel and at what resolution that records at. It may be hard to make out subjects at 320×240 or 640×480 pixels, especially at 7 FPS, so if you want a truly effective security camera system, you probably want to up your expectations on pricing, etc, and go ahead and spend the extra money to be truly protected.
If you have had experiences where buying higher quality equipment has saved you in the long run, or visa-versa, please let us! Real world applications provide the true value that allows people to make educated decisions about future projects and purchases, and we really appreciate them.
Security Cameras & CCTV Practices – Nov 30, 2009 – 2nd Ed.
Welcome to the November 30, 2009 edition of the Security Cameras and CCTV Practices blog carnival. We have a lot of new material in this edition, including one submission from another contributor! We are excited to have multiple contributors to this publication and do not want to be the only one submitting valuable content, so please, if you have industry-relevant blog articles, follow the submission link at the bottom of this edition.
CCTV Security Cameras
ApexCCTV presents Home Security Systems – a Cost Benefit Perspective posted at The CCTV Blog, saying, “It is becoming more and more cost-effective and important to own and install your own home security system. ApexCCTV’s Jon Hough lays it out in a short cost-benefit perspective.”
Digital Video Recorders
Shawn Taylor presents Surveillance Video Recorder ? Which One is For You posted at Hidden Surveillance Camera.com.
ApexCCTV presents Computer or PC-Based Security DVR Running Slow? – Try these Tips First posted at The CCTV Blog, saying, “Many times you will find that a PC slows down over time and begins running slow, etc. Shaun, one of ApexCCTV’s technicians, details some FREE and easy ways to speed up your computer and protect it with general maintenance and software programs.”
Software
ApexCCTV presents GeoVision & Windows OS Issues & Troubleshooting posted at The CCTV Blog, saying, “Security experts utilizing GeoVision’s systems have experienced many issues over the years with Windows integration. ApexCCTV’s lead technician shares some of those issues and the troubleshooting measures that should be taken if you are experiencing these Windows Operating System issues with your GeoVision System.”
ApexCCTV presents Detecting & Battling Key Loggers, Computer Monitoring & other Malicious Activities posted at The CCTV Blog, saying, “Malicious computer surveillance and monitoring is a very viable concern in today’s internet age. There are many ways to detect such malicious activity, some of which are detailed in this article.”
Training & Informational Videos
ApexCCTV presents How Many Frames per Second? A Comparison Video posted at The CCTV Blog, saying, “When choosing a security camera system, the recording frame rate of your DVR (digital video recorder) is a large part of the purchasing decision. The video and information in this article should make that decision much easier by showing you exactly what you’ll be getting.”
That concludes this edition. Submit your blog article to the next edition of security cameras and cctv practices using our carnival submission form. Past posts and future hosts can be found on our blog carnival index page.
Technorati tags: security cameras and cctv practices, blog carnival.
How Many Frames per Second? A Comparison Video
In the CCTV world, the Frames per Second (FPS) question not only effects the video quality of a recording, but the cost effectiveness of a system, as well. Many people come in looking for a “real-time,” or 30 FPS display/record system, but then compromise for a 15 FPS counterpart to save on expenses.
Truth be told, the visible difference between a 15 and 30 frames per second video isn’t terribly drastic. When you start dropping down to 7.5 FPS, on something like a 4 Channel DVR that only records at 30 FPS (total), you can really start to notice the choppiness, though. For the most part, you don’t see many systems out there that record below 7.5 frames per second by default – at that point the choppiness is highly visible and you don’t get a good look at the subjects in the frame.
View Frames per Second Comparison Video
We created the above video to demonstrate the different FPS values in a controlled environment. The subject is recorded at 3, 8 , 15 and 30 frames per second, on the same DVR and camera, walking outside the building. We hope this video helps you determine which level of recording you need for your next system.
Don’t forget to let us know your thoughts on FPS values & recording DVRs – is it worth it to skimp on FPS, or do you go big or go home with 30 every time?
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