CVBS

CCTV cameras are a type of security camera that uses an analog video signal (CVBS / Composite Video Baseband Signal) to capture video surveillance footage. Analog CCTV cameras are hard-wired to surveillance DVRs and monitors using coax cable such as RG59. In addition to analog cameras.

CVBS – video signal transmission standard

Composite Video also referred to as the CVBS (Composite Video Baseband Signal) is an analog video transmission signal without audio that contains image data in the standard resolution of 480 and 570 or (480 lines or 576 lines interlaced).

The video data is encoded in a single channel and unlike slightly higher resolution S-Video using two channels and higher quality Component Video using three or more channels.

Composite Video is often transmitted using standard formats including PAL, NTSC, and SECAM and is often referred to as CVBS.

A composite video signal combines information required to broadcast a color video as well as frame and line synchronization pulses in a single cable. Video signal color is a linear combination of image brightness and modular sub-carrier chrominance transmitting information about the color and a combination of hue and saturation. The coding process details differ between PAL, SECAM, and NTSC systems.

A combination of chrominance and luminance is a frequency division technique; however, it is much more complex than a typical frequency division multiplexing system i.e., used in analog radio station multiplexing in AM and FM bands.

CVBS signal includes a “Color Burst” signal (color sync signal) at the beginning of each scan line, based on which the receiver can restore the attenuated carrier chrominance signals (color) and thus decode the color information. The Color sync signal is phase reversed (180° from the phase) concerning the reference sub-carrier

Composite Video signals can be easily directed to each transmission channel by modulating a corresponding RF carrier wave with the signal. During the CVBS signal broadcast on different devices, the signal can be output at VHF and UHF frequency, i.e., it can be broadcasted on a selected TV channel.

In-home applications, the composite video signal is usually connected via RCA (cinch) port usually marked yellow. High-quality coaxial cables often use BNC connectors, e.g., TV studios, digital CCTV recorders, and post-production.