Apple Final Cut Pro 6 User Manual

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Synchronizing Equipment with a Blackburst Generator

With most professional editing systems, you capture video, audio, and timecode via
separate cables. It’s important that when you capture, the VTR and the video and audio
interfaces are synchronized via a common video timing signal. If digital audio samples
and video lines and frames are not precisely synchronized, they eventually drift apart
because they are captured at slightly different rates.

Using a common sync source is especially important when you are independently
capturing long segments of video and audio to synchronize together later. If your
audio deck and capture interface are not both receiving the same timing information,
the sync between the audio and video portions of clips might drift over time.

A blackburst generator provides a common timing signal (or clock) to lock together
the timing clocks of all devices in a system. This is sometimes referred to as external
sync or house sync because every device in an entire facility can be timed to this
common reference.

Professional VTRs, camcorders, audio devices, and interfaces often have the ability to
accept sync signals from an external device. These connectors are labeled “genlock”
(short for generator lock), “external sync”, “reference input”, or “reference video”. On some
equipment, the normal composite video input of a device can be used to lock to
external sync.

Important:

To synchronize your video or audio devices and interfaces, they must all

accept an external clock source (such as a blackburst generator).

When you genlock a deck and a video or audio capture interface, one output of the
blackburst generator should be connected to the external sync input of the video or
audio deck, and another output should be connected to the external sync input of your
audio interface.

PCI card

Computer

Analog or digital VTR

Video

Reference video

Breakout box

Audio

Blackburst

generator