Composite Video Signals

A composite video signal is a signal in which all the components needed to generate a video signal are embedded in a single signal. The three main components that together form a composite signal are as follows:

  • The luma signal (or luminance)—Contains the intensity (brightness or darkness) information of the video image
  • The chroma signal—Contains the color information of the video image
  • The synchronization signal—Controls the scanning of the signal on a display such as the TV screen

The monochrome composite signal is built of two components: luma (or luminance) and synchronization. This signal, which is usually called the Y signal, is shown in the following figure.

Monochrome Composite Video Signal (Luma Steps from White to Black)

The chroma signal by itself, which is usually called the C signal, is shown in the following figure.

Color Information Signal for a Color Bar Line (Including the Color Burst)

The composite color video signal, often called the Color Video, Blank, and Sync (CVBS) signal, is the sum of Y and C.

CVBS = Y + C

Color Composite Video Signal for a Color Bar Line

The two components Y and C can also be distributed separately as two independent signals. These two signals together are called either Y/C or S-video.

Y/C = S-video

Component Video Signals

A component video signal is a signal in which all the color components needed to generate a video signal are transmitted separately. Most HDTV formats are component (Y-Pb-Pr).