NTSC stands for National Television System Committee. In the context of CCTV systems, NTSC refers to a video format that was predominantly used in North America, parts of South America, and some other regions. It defines a set of technical standards for the transmission and display of analog video signals.
The NTSC video format specifies the following parameters:
- Frame Rate: The NTSC standard specifies a frame rate of approximately 30 frames per second (29.97 frames per second to be precise). This frame rate provides smooth motion in video playback.
- Resolution: The NTSC format supports a video resolution of 720 x 480 pixels. This resolution is commonly referred to as Standard Definition (SD) and is lower than the resolutions used in modern high-definition (HD) or ultra-high-definition (UHD) systems.
- Aspect Ratio: The NTSC format uses an aspect ratio of 4:3, which means the width of the video image is 4 units for every 3 units of height. This aspect ratio is more square-shaped compared to the wider 16:9 aspect ratio commonly used in modern HD and UHD systems.
- Color Encoding: NTSC utilizes a color encoding system called composite video, where the luminance (brightness) and chrominance (color) information are combined into a single signal. This encoding method allows the transmission of color video over analog systems.
It's important to note that NTSC is an analog video format and has been largely superseded by digital video formats such as IP (Internet Protocol) cameras and the associated video standards like H.264 or H.265. Digital video formats offer higher resolution, better image quality, and more advanced features compared to the limitations of analog NTSC systems.
However, when specifying CCTV systems, the term "NTSC" may still be used to indicate compatibility with legacy analog systems or to denote certain characteristics of the video signal, such as frame rate or resolution. It's worth noting that in regions that use the PAL (Phase Alternating Line) standard, a different set of specifications is followed.