Archive for category Security DVR
How Recording Resolution Effects a DVR’s Frames per Second
Posted by rhill in CCTV Articles, CCTV Security DVR Cards, Security DVR on December 7, 2009
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.
Large Storage Partitions for Surveillance DVRs
Posted by eburcham in CCTV Articles, Security DVR, Software on November 16, 2009
It is downright amazing how many people are struggling with large volumes for storage, even on Vista and Windows 7.
Here are the SUPER BASIC rules. There are only three of them, so pay attention, M’Kay?
- You CANNOT install windows on a standard MBR disk and then extend it beyond 2 TB. Forget it. It WON’T work.
- You need to create your disk as a GPT disk FIRST. Then, if you want to put an OS on it, you can. But I don’t recommend it. See REALLY CRITICAL NOTES below.
- As a best practice you need to boot from an MBR drive and store video on a GPT disk.
OK, now the long version.
MBR disks: You’ve been using this since the dinosaurs became extinct. For most applications, you’ll continue using it until the aliens give us new technology. These drives can typically only have four partitions, and Windows (all flavors, without a huge effort) can only effectively use 2 TB of space on a MBR disk. This means that if you want lots of storage, you don’t use these.
GPT disks: This is the new delicious flavor, and as such it is rare and difficult to find in ordinary use. GPT volumes offer several benefits:
- They allow up to 128 primary partitions.
- They allow a much larger volume size – greater than the 2 TB, which is the limit for MBR disks.
- Provides greater reliability due to replication and cyclical redundancy check (CRC) of the partition table.
- Can be used as a storage volume on all x64-based platforms, including platforms running Microsoft Windows XP Professional x64 Edition. Windows Server 2003 SP1 also enabled support for GPT in x86 versions of the Windows Server 2003 family.
REALLY CRITICAL NOTES:
- Windows x64 Editions and Windows Server 2003 SP1 operating systems support the use of GPT volumes as data volumes ONLY! This is because x64 and x86 architectures do not support an EFI boot partition and you simply cannot use a GPT drive to boot an x64-based computer with a legacy BIOS.
- On Intel Itanium platforms, Window supports the use of GPT drives as boot drives OR data volumes.
So, what the heck does this all mean? Here is the long version of how to handle this. You’ll need to following to try it out:
- A PC Built with at least two logical drives. One needs to be a MBR disk. This is where you will install windows.
- The 2nd logical drive should be larger than 2TB, so we’re talking about a RAID array until they come out with individual hard drives bigger than 2TB. I would suggest a 3-Ware RAID card, but lots of people in the surveillance business use Highpoint cards and they seem to work fine as well.
- A capture card and related software.
Here are the steps you need to follow:
- Enter your RAID BIOS and create a 2TB RAID array. It really should be RAID 1, 5, or 10 guys.
- Install Windows on this 2TB array, using about a 64 GB partition for Windows.
- Let the PC sit tight while the RAID array finishes initializing. Just take my word on this one.
- Once the array has initialized, create the largest partition you can (using disk manager) in the remaining space on your 2 TB array.
- Install your capture card software on your C: drive (the 64GB partition) and point it to use the bigger partition for storage.
- OK, no you have a stable DVR with a 2TB system and you still have MORE than 2TB leftover in your RAID card for further storage. This is where you make your GPT partition.
- In your RAID management software, make a RAID 5 (10 if you have the drives) array with all remaining disks on the controller. This should wind up being > 2 TB.
- Once this new logical disk has initialized, open drive manager, and convert it to a GPT disk.
- Voila! Now you can create a huge volume (or many volumes) using all the space in that RAID array!
Here are some wonderful links to further explain MBR and GPT disks:
GPT Disks – http://en.wikipedia.org/wiki/GUID_Partition_Table
MBR Disks – http://en.wikipedia.org/wiki/Master_boot_record
PC Based DVRs vs. Standalone DVRs
Posted by gfutrell in Comparisons, Security Camera System, Security DVR on October 14, 2009
I get calls on a daily basis asking which I prefer, PC based or Standalone DVRs. In most cases I would have to say PC based systems. Don’t get me wrong, the standalone units are great for small budgets, but when you need to retrieve the data from one or expand your system…
Standalone DVR Overview
Several people want to use the smaller, less expensive DVR… and for good reasons. One would be cost; they range in price from a couple hundred to a few thousand dollars. Also, they have all the operating system software written directly into the motherboard, making them more secure from outside threats. Some have a fairly simple menu and even use a remote control or mouse for on-screen navigation, too.
Overall, though, these smaller, less expensive units all have a few failing points. Since the standalone DVRs typically use a Linux based operating system, they are often difficult to link to a PC for backups, etc. Several have built in CD/DVD burners that allow you to backup your security camera footage directly, but you still need a PC to play the files. This is where the fun begins; you will likely need special software or video codecs to view the file on your PC! Sometimes the DVR will come with the needed software, but if you are reading this post because yours did not, I would suggest downloading the “K-Lite Codec Pack – FULL.” Once installed, that should allow you to play almost any video you will ever come across. If that does not work, I would say contact the manufacturer or check out their website to see if they can offer any insight.
The final “con” associated with Standalone DVRs is that they are basically trash if the unit ever stops working. Most of the time you get your money’s worth, though.
PC-Based DVR Overview
I would much rather look to the long term of the device I purchase. With a PC-based DVR, you have a lot more versatility and power, but also a larger price tag. You have all of the options that Windows gives you, and unfortunately the drawbacks too. One major “pro” is that you have the ability to upgrade the DVR to a more powerful system and add additional CCTV cameras later, if wanted. The added ability to choose a surveillance company’s DVR card and the options that they provide increases the desirability, in my opinion.
These systems allow for more reliable control over your security system and the ability to extract the DVR data, when needed, is easier. Larger companies, such as banks, schools and casinos, rely on the options given by these extremely customizable PC-based DVRs. Being Windows systems, the CD/DVDs that you backup to can be played on any similar windows system (may still require codec updates).
In summary, PC-Based DVRs can make surveillance at home, business or school easier to deal with, but they still have a few drawbacks, such as power cost, size and having to use Windows Vista in most cases. Overall, I prefer my video surveillance be done with a PC.
Questions or Comments? Don’t be afraid to comment on the blog or contact us directly. We’d be happy to assist you in making the right decision for your application!
Digital Video Recorder: Not Just Your TiVo
Posted by cbartell in Comparisons, Security DVR on September 9, 2009
When you think of a Digital Video Recorder (DVR), the first thing that comes to mind is more than likely the TiVo sitting on a shelf near your TV. However, a DVR doesn’t just record television shows. Specific types of CCTV DVRs can be used to record the video (and audio) that your surveillance cameras capture. Of course you have to own a DVR that is specifically made for this purpose.
The types of DVRs used for security are the PC-based and standalone DVR. It is a good idea to be familiar with the basics behind these when choosing a security DVR for your home or business.
Let’s take a look at both.
PC-based
The PC-based DVR can come in either a tower (normal PC) or a rack mount form. It includes all of the same components as your household or work computer, as well as a video capture card, or cards, which is the device that captures the video and audio from your cameras. The PC typically runs on a Windows operating system. This type is easier to upgrade and modify in the future. It also offers better video recording quality, more advanced features and can easily be integrated with your alarm or POS system. A PC-based DVR is good if you plan on setting up a surveillance system for large projects, such as casinos, banks and airports.
Standalone
A standalone DVR looks like and is about the same size as a standard DVD or VCR player. All of the software and components are built-in, and the DVR runs on either a Linux-based or proprietary-based operating system. Because a standalone only runs one application, it is less likely to experience software failure. These systems are easy to install and use, offer a variety of functions and are less expensive than PC-based DVRs. If you are installing a security camera system in your home or small office, a standalone DVR is the way to go.
As you continue to build your home or business surveillance system, it is important to compare between the two types and decide which will be best suited for your operation. After you have, come back and share your hints and tips about purchasing a security DVR by leaving a comment. Thanks for reading!
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