pedestal
The black shoulder, pedestal, is a reference level signal in television and video technology. There are two black shoulders, the front and rear black shoulders. They are located within the blanking interval before and after the horizontal sync pulse and reference the black level for the television picture.
The black shoulder is the reference value for black is fixed by a clamping circuit. The front black shoulder is 1.5 µs wide, it is located before the line sync pulse immediately after the end of the visible line. The rear black shoulder has a duration of 5.8 µs, it is located behind the synchronous pulse immediately before the beginning of the line. On it, the burst is transmitted with the color carrier.
In the PAL television standard, the entire line blanking has a duration of 12 µs. Of this, 1.5 µs is allotted to the front black shoulder, 4.7 µs to the sync pulse, and the remaining 5.8 µs to the rear black shoulder.