Surveillance DVR Frequently Asked Questions

What type of connectors are used to connect DVRs to security cameras?
All of our surveillance DVRs have female BNC connectors for camera inputs. Our security cameras have a female BNC connection. Our Video & Power cables have two male BNC ends which connect cameras to a DVR.

What type of monitor can be connected to a DVR?
This depends on which DVR. There are three types of video outputs that vary by DVR model. The three types of video output connections are: BNC, S-Video, and VGA.

A BNC video output can be connected to CCTV monitors (BNC inputs) or connected to a standard television with RCA video input but using a BNC to RCA male converter.  You CAN NOT convert the BNC cable to a F-connector and connect to the CATV (cable tv) input of a television.  CATV input is different from video input and can not be used for surveillance system monitors.

An S-Video outputs can be connected to a standard television monitor which has an S-Video input. Most modern televisions have s-video inputs and/or RCA video inputs.

A VGA output can be connected to a standard VGA computer monitor.

Please consult our surveillance dvr page and review the features of the DVR you are interested in to determine which type of video output is supported or call us if you need help in determining this.

What does Pre / Post Alarm recording mean?
Pre and Post Alarm Recording allows the DVR to be configured to record before and after an alarm has been triggered.

What is MPEG4 video encoding?
The Motion Picture Experts Group (MPEG) released MPEG-4 encoding in 1998. The basic idea behind MPEG is that compressed images are compared before being transmitted over the network. The first compressed image is used as a reference and compared to the images that follow it in the video sequence. The first image is transmitted over the network along with the parts of the following images that differ from the initial reference image. The viewing application on the receiving end of the transmission then reconstructs all images based on this information and displays the result. This is a simplified description of how MPEG-4 works.

What is MJPEG video encoding?
Motion JPEG (MJPEG) is a video encoding where each frame of video is captured and compressed into a separate JPEG image. The resulting quality of video compression is independent from the motion in the image.

What is MJPEG2000 video encoding?
MJPEG2000 or MJ2K is an adaptation of the JPEG2000 standard used for still photos. MJPEG2000 treats a video stream as a series of still photos, compressing each individually, and with no interframe compression. Because no interframe compression is used, it is ideal for editing. The JPEG2000 standard is the offical successor to JPEG and will eventually replace the older JPEG standard for high-quality image compression.

What are the advantages/disadvantages of MPEG4 video encoding versus MJPEG video encoding?
The video sequencing compression that is used my MPEG4 allows it to use less network bandwidth and storage that MJPEG. MPEG4 videos generally have a slightly lower image quality when compared directly to an MJPEG video. This is not very noticable when viewing but is more important if video images need to be editted, which is normally not applicable in surveillance video. MJPEG and MJPEG2000 capture a stream of individual JPEG images while MPEG4 captures changes to images to create video.

What does NTSC mean?
NTSC is an abbreviation for the National Television Standards Committee. The term "NTSC video" refers to the video standard defined by the committee, which has a specifically limited color gamut, is interlaced, and is approximately 720 x 480 pixels, and 30 frames per second (fps). This standard is used in North America.

What does PAL mean?
PAL is an abbreviation for Phase Alternating Line. This is the television display standard that is used mainly in Europe, China, Malaysia, Australia, New Zealand, the Middle East, parts of Africa, and other parts of the world. PAL uses 625 lines per frame and a frame rate of 25 frames per second.