chrominance subcarrier

Where composite video is in use, the phase of the chrominance subcarrier of each source being combined or switched should also be coincident.

The chrominance subcarrier is a separate subcarrier signal that carries the color information during transmission of a video signal.

Some examples are, picking up a radio station among several that are close in frequency, or extracting the chrominance subcarrier from a TV signal.

Colorburst is an analog video, composite video signal generated by a video-signal generator used to keep the chrominance subcarrier synchronized in a color television signal.

Designers chose to make the chrominance subcarrier frequency an n + 0.5 multiple of the line frequency to minimize interference between the luminance signal and the chrominance signal.

Depending on the video standard, the chrominance subcarrier may be either quadrature-amplitude-modulated (NTSC and PAL) or frequency-modulated (SECAM).

To provide sufficient bandwidth for the chrominance signal, yet interfere only with the highest-frequency (and thus least perceptible) portions of the luminance signal, a chrominance subcarrier near 3.6 MHz was desirable.

The vectorscope locks exclusively to the chrominance subcarrier in the video signal (at 3.58 MHz for NTSC, or at 4.43 MHz for PAL) to drive its display.

The frame number modulo 2 (for NTSC and SECAM) or modulo 4 (for PAL) should be preserved across cuts in order to avoid phase jumps in the chrominance subcarrier.

Additionally, in order to minimise beat-patterns between the chrominance subcarrier and the sound subcarrier, when PAL is used with System I, the sound subcarrier is moved slightly off the originally-specified 6.0 MHz to 5.9996 MHz.

That portion of the composite color signal, comprising a few cycles of a sine wave of chrominance subcarrier frequency, which is used to establish a reference for demodulating the chrominance signal; Normally approximately 9 cycles of 3.579545 MHz.

In video engineering, color framing refers to the color frame sequence of fields in a composite video signal through which the video frame timing and chrominance subcarrier signal timing-in particular, that of the color burst - cycle through all possible phase relationships.