Dolby Frame Synchronizer

The terrestrial broadcast, cable, and satellite industries routinely need to synchronize externally generated Dolby E or Dolby Digital bitstreams to match their internal plant reference. The DP583 accepts all Dolby E and Dolby Digital frame and data rates, as well as PCM inputs, and provides an output that is reframed to match the local plant reference. The DP583 also allows postproduction facilities to reframe Dolby E streams that have been stored on recorders that do not have video frame reference capabilities, such as DAT. The DP583 can operate with either a tracking or fixed delay. In both modes the output clock can be derived either from the video black reference or the AES reference. When tracking with Dolby E, the video reference provides framing information; when tracking with Dolby Digital or PCM, a standard TTL input signal provides the framing. The TTL input is compatible with most video frame synchronizers. When tracking, fixed delay can also be added to Dolby E, Dolby Digital, and PCM signals individually. The front panel of the DP583 features a two-line, 16-character alphanumeric display and menu navigation buttons to facilitate operation of the status and setup menus. The DP583 displays the incoming bitstream type (Dolby E, Dolby Digital, or PCM), program configuration, and the current delay through the unit. Any buffer drops or repeats are counted and stored for subsequent retrieval. Front-panel LEDs indicate power-supply status, presence of digital input and video reference signals, plus LEDs activated by error or fault conditions. These are mirrored on the GPI/O status port. An RS-232 connector on the front panel and RS-485 connector on the rear panel are available for software upgrades and status monitoring. The DP583 contains dual redundant power supplies for fail-safe operation in broadcast critical paths.

Dolby Laboratories, Inc., 100 Potrero Avenue, San Francisco, CA 94103-4813. Tel: 415-558-0200; Fax: 415-863-1373.