Dolby Laboratories DP572 - Manual (Page 35)

Dolby E Multichannel Distribution System User Manual DP571 Dolby E Encoder
3-3
3.1.1 Digital Inputs
A maximum of eight PCM channels can be sent to the Digital Inputs, each with a loop-
through connection.
3.1.2 Video Reference
An analog composite video reference signal is required for Dolby E encoding. Versions
1.05 and 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).
3.1.3 LTC 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.
3.1.4 PCM 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.
3.1.5 Metadata
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.
3.1.6 Remote
Future versions of the DP571 will allow remote control via the front- (RS-232) or
rear-panel (RS-485) ports.