Black_and_burst
Black and burst
Analogue synchronization signal used in broadcasting
Black and burst, also known as bi-level sync and black burst, is an analogue signal used in broadcasting. It is a composite video signal with a black picture.[1] It is a reference signal used to synchronise video equipment, in order to have them output video signals with the same timing. This allows seamless switching between two video signals.
Black and burst can also be used to synchronise colour phase and provides timing accuracy in the order of tens of nanoseconds which is necessary to perform e.g. analogue video mixing.
Black and burst exists for various colour TV standards, such as PAL, NTSC and SECAM. Because the black and burst signal is a normal video signal, it is transportable via normal video cables and through video distribution equipment.[2]