The digital information must be changed back to analog.

Time Base Correctors (2)

D to A Conversion

This digital video can't be integrated with analog video, so it has to go through a D to A (digital to analog) converter to be changed back to analog information. As a result, corrected analog video comes out of the TBC.

Video Proc Amp

In addition, TBCs have an internal proc amp (video processing amplifier). As previously noted, the quality of the sync itself may have deteriorated owing to factors such as copying a tape. However, proc amps have their own sync generators, so that when the distorted sync comes off the tape, the proc amp strips it away and inserts new, clean sync in its place. Proc amps also enable you to adjust some of the video parameters, such as brightness, chroma intensity, phase, and pedestal (black level).

Window of Correction

Each TBC will have what is called a window of correction. As you might suspect, this tells you the maximum amount of time base error it can correct. A TBC with a four-line window might be fine for VTRs and tapes that never leave the climate-controlled confines of a studio, but it would be almost useless with tape shot out in the field. A TBC with a 32-line window will cost a good deal more money, but it should be able to handle anything shot in the studio or the field.

Without proc amp.

With proc amp.