Dolby Laboratories DP572, DP571 user manual Digital Inputs, LTC Input, PCM Delay Input

Dolby E Multichannel Distribution System User Manual DP571 Dolby E Encoder

3.1.1Digital Inputs

A maximum of eight PCM channels can be sent to the Digital Inputs, each with a loop- through connection.

3.1.2Video Reference

An analog composite video reference signal is required for Dolby E encoding. Versions

1.05and later support two frame rates: 29.97 Hz (NTSC) and 25 Hz (PAL). VITC information can also be extracted from the video reference signal.

If the video reference signal is not present or invalid, the:

•DP571 will not encode the Dolby E bitstream;

•outputs will all be muted;

•VRef LED will be red (Vref not present) or yellow (Vref unequal to frame rate of Dolby E Main Output).

3.1.3LTC Input

The DP571 accepts a SMPTE LTC signal. After decoding in the LTC receiver, the resulting time code information is passed to the DSP subsystem.

3.1.4PCM Delay Input

When sending both encoded and non-encoded channel pairs to a digital recorder, the non-encoded pair must be delayed to remain synchronized with the encoded signal. The encoder contains a one video frame PCM utility delay that allows the PCM input signal to be transported in parallel with the Digital Inputs.

3.1.5Metadata

The DP571 receives, generates, and modifies metadata information. Metadata is received through the rear-panel input from an external source, such as an authoring system, and embedded into the Dolby E bitstream. See Section 3.2.4 - Metadata Params for a discussion of metadata parameters that might need to be explicitly set or checked.

3.1.6Remote

Future versions of the DP571 will allow remote control via the front- (RS-232) or rear-panel (RS-485) ports.

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