Introduction
Composite Video (Composite Video):
Chinese Interpretation: Composite Video Broadcast Signals or Composite video blanking and synchronization
full name: Composite Video Broadcast Signal or Composite Video BLANKING AND SYNC
Composite Video, is also called a baseband video or RCA video, is a National Television System Committee (NationaltelevisionStandardsCommittee) , NTSC) The traditional image data transmission method of the TV signal is transmitted in an analog waveform.
Composite Video Interface: Composite Video Video Signal is defined as a single-way analog signal including brightness and chroma, i.e., separating the video signal after the full TV signal, the color The degree signal is also a high end inserted between the brightness signal. Since the brightness and chromation of the composite video are interposed together, it is difficult to recover exact colors when the signal is reproduced. This signal typically passes through a cable input or output to a household recorder, its signal bandwidth is narrow, generally only the decomposition rate of about 240 lines. Early televisions have only antenna input port, and the newer TVs are equipped with composite video inputs and outputs (Video IN, Video Out), which can also be directly input and outputted the demodulated video signal. The video signal does not contain high frequency components, processes relatively simple, so the video card of the computer generally acquires the video signal using the video input.
Classification
CVBS interface
CVBS is "Color, Video, Blank and Sync", "Composite Video Baseband Signal," Composite Video Burst Signal ", Abbreviation for or "Composite Video with Burst and Sync".
CVBS is a widely used standard, also called baseband video or RCA video, is a traditional image data transmission method of the National Television System Commission (NTSC) TV signal, which transmits data in an analog waveform.
It is a simulation TV program (picture) signal combined with the sound signal and modulates the format before the radio frequency carrier.
av = audio + video, in fact, the video is the CVBS
RCA interface
Composite Video Signal (CVBS) interface, that is, the usual RCA interface.
RCA is the abbreviation word of Radio Corporation of American, because the RCA joint is invented by this company.
RCA is commonly known as the lotus socket, also called the AV terminal, also known as the AV interface, is usually a pair of white audio interfaces and yellow video interfaces, which usually use RCA (commonly known as lotus head). It only needs to connect the standard AV cable with lotus head and the corresponding interface.
RCA connector is a tone / video terminal terminal that is currently the most common. The RCA audio terminal is generally labeled in different colors: the right channel is used in red, the left channel is black or white. In general, the RCA stereo frequency line is a group of left and right channels, and each channel is a line. Usually a pair of audio interface right channel (red) left channel (white) and video interface (yellow)
Composite video (Composite) is usually used in yellow RCA (Lotus socket) joint. The "compound" meaning is an analog signal to transmit brightness and chroma signal in the same channel, but if the TV is not well separated from these two signals, it will appear. The audio interface and video interface are used, which is usually a white audio interface and a yellow video interface. It is connected to the RCA (lotus head). It only needs to connect the standard AV cable with lotion and the corresponding interface when used. Option (but some need software support).
AV interface
Composite video interface is also called AV interface or video interface, is currently the most common video interface, almost all TV, VDR products have this interface.
AV compound (Composite) video interface, analog interface, audio, video separation video interface, usually made from three independent RCA plugs from yellow, white, red (also called plum blossom interface, RCA Interface), where the V interface is connected to the mixed video signal, which is a yellow socket; the interface connection left channel sound signal, which is a white socket; the R interface is connected to the right channel sound signal, which is a red socket
due to The video signal is not included in the video signal, so generally with the video input, the output port is supported, and the audio input, AUDIO IN (AUDIO OUT) is transmitted synchronously. Therefore, sometimes the composite video interface is also called an AV (Audio Video) port. The
AV interface enables separation transmission of audio and video, which avoids the decrease of image quality due to tone / video mixing interference, but since AV interface is still a brightness / chromaticity ( Y / c) Mixed video signals need to be bright / color separation and chrominance decoding to imaging, in the first mixing, and the residual processing process will inevitably cause loss or distortion, chrominance signal, and brightness signals. There is a big chance to interfere with each other. Due to the technical defects inherent in the highlight / chroma (Y / c) mixed video signal processing, the application of the AV video interface has great limitations.