Choosing the right DVR for surveillance purposes can be a challenging task for most of us, especially those who have no idea about electronics and other technology related to it. There are actually many factors to consider, and while it looks fairly easy, there are still those who have difficulty in making decisions when it comes to putting up their security camera and surveillance system set at their areas of choice. Oftentimes, two DVRs may seem to be very similar, when in reality they are very different in many ways. The very first decision to make in choosing which security DVR for surveillance purposes is the right one for you is to determine what level of investment you are willing to make, and whether you require an entry-level unit or a high-end unit in order to accomplish your goals. The specifications that you need to consider are the following:
- Frame Rate
Frame rate is defined as the number of frames a DVR can record at a given resolution each second. Real time is considered to be at about 30 frames per second. Thus, in order to record in real-time video on 16 channels, you will require a unit that can record a total of 480 frames per second (FPS). Remember that lots of units claim to be real-time due to the fact that they display live video at 30 FPS on each channel. Do not fall for this trick since what is truly important is the recorded video, not the live video feed. A lower-quality unit will most often record at far less than 30 FPS on each channel while a higher-quality unit will be able to record 30 FPS on every channel.
- Resolution
The resolution is defined as the size of the image being displayed or recorded. The most commonly known resolution size in the industry of surveillance is CIF (360 x 240). At this time, the highest recording resolution in a standalone DVR is D1 (720 x 480). Resolution is very important because the bigger the image that is being recorded, the more detail you can distinguish and determine from the scenario. A 4CIF image has 4 times the detail of a standard CIF image. As a matter of fact, lots of the lower-quality DVRs can record CIF resolution. The higher-quality units can record both D1 and 4CIF resolution while the highest-quality units can record D1 and 4CIF resolution in real time (30 FPS) on each channel simultaneously.
- Storage Capacity
A very important factor to consider when getting a security DVR is its storage capacity. Lower-quality DVRs often allow for 1 to 2 hard drives only. The more advanced DVR units can often accommodate 6 or up to 8 hard drives internally. The most advanced DVR units will allow for redundant storage (RAID) configuration and FTP uploads. FTP uploads is a very useful tool which lets a DVR to back up video to an off-premises FTP server whenever an event occurs. This lets a business owner or personnel to retrieve video of a thief even if he stole the DVR itself during the theft.
- Compression
When video is transmitted to the DVR, it is compressed to conserve storage and make Internet viewing more smooth and fluidlike. The compression
utilized can vary from nearly no compression like MJPEG or wavelet, to the higher compression methods such as MPEG4 or the current highest compression available which is H.264. Compression methods may vary between security digital video records. There are even DVRs that utilize a combination of compressions – one meant for recording and one meant for streaming over the Internet. Lots of the newer DVRs nowadays use H.264 which is 40% more efficient both in Internet streaming and storage.
- Video Output
Lower-quality DVRs will most often only offer BNC video output which would require the use of a BNC to VGA converter in order to view the DVR on a standard VGA monitor. Higher-quality units will have a VGA output and a BNC output. The highest-quality units will also possess an HDMI output.
- Audio Recording
There are some DVRs that will allow synced audio recording. Lower-quality units will only get to record 1 to 4 channels of audio, whereas the higher-quality ones often allow up to 16 channels of synced audio recording.
- DSP Chipsets
Due to the fact that the standalone DVR utilizes hardware compression, the engine of the unit is the processor/s. Even if specs between DVRs may appear to be similar, the quality and number of DSP chips is what gives the DVR its processing power. Lower-quality units will utilize chipsets that are found in cheap video cameras. They will not be able to do a good job in compressing video, and so it will affect the quality of the recorded footage. The higher-quality units utilize more expensive yet more advanced chipsets that will enhance video quality and the overall stability of the DVR. Moreover, the more chipsets used, the better the overall performance the DVR. Lower-quality DVRs will only use 1 chipset to operate all channels, whereas higher-quality DVRs may use either 3 or 4 DSP chips in a single DVR. This will also typically determine how many functions a single unit can perform in one go. For example, a triplex machine can perform only 3 functions at one time (internet view, record, live display) while a more advanced machine with more processing power can perform 5 functions at the same time (pentaplex). Five functions will include internet view, record, live display, playback and configuration all at the same time.
- Remote View
Many DVRs nowadays are networkable and can let a person to log in with the use of Internet Explorer in order to view their security cameras remotely. The more advanced units possess a client software that lets a user to view multiple DVRs at the same time. This software may also have many features such as camera groupings, e-mapping, various user levels, the power to restrict access to individual functions and security cameras for each user, and many more.
The specifications mentioned above are some of the most common things that you need to consider when choosing security DVRs for your surveillance needs. Do your research or ask a surveillance professional for advice when you are having difficulties in understanding the technology behind security DVRs. This will help you make the most out of your security camera and surveillance system set.
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