Cobalt Digital COMPASS 9085 Loudness Processor - Manual (Page 17)

9085-OM (V4.3) 9085 PRODUCT MANUAL 1-13
Introduction
9085 Functional Description
AES Audio Input Advanced Features
AES Sample Rate Converter
The 9085 AES inputs have sample rate converters that can be independently
enabled for each AES pair to allow the card to interface with asynchronous
AES sources (sources in which AES timing does not match the video input
timing). The sample rate converters are set to disabled (bypassed) by default;
this is necessary when embedding undecoded, non-PCM data such as
Dolby
® E or Dolby ® Digital™ audio streams. When a valid Dolby ® E or
Dolby ® Digital™ signal (in accordance with SMPTE 337M) is detected on an
AES or embedded audio signal, SRC is automatically bypassed along with
gain and polarity controls.
Zero-Delay Audio Embedding
In cases where additional delay must be avoided, it may be desirable to embed
AES with minimum latency. Using zero-delay embedding, the video can then
be delayed by one frame to account for any remaining audio delay. In this
manner, any delay between video and audio can be cleanly contained and
managed within one frame period.
When zero-delay audio embedding is enabled for a given AES pair, the pair is
directly embedded into its corresponding group (for example, AES Pair 1 into
embedded channels 1 and 2; AES Pair 2 into embedded channels 3 and 4, and
so on) with the normal audio sync delay being bypassed.
This function overrides the audio routing system (for example, if AES Pair 1
is selected then the controls to route AES Pair 1 into other embedded channels
will not apply). Gain and polarity control is not available when this option is
selected. Zero-delay audio embedding is set to Off by default.
Low-Latency AES Passthrough
This function is similar to zero-delay audio embedding. If low-latency AES
passthrough is selected for a given input pair, it causes the corresponding
AES output pair to act as a bit-for-bit copy of the corresponding AES input
pair.
This control overrides the normal audio routing and delay. Gain and polarity
control is not available when this option is selected. Passthrough is set to Off
by default.
Dolby Decoding Option (+DEC)
If your 9085 is equipped with Dolby ® decoding as an option, refer to
supplement “Dolby Decoding Option (+DEC)” (PN DDO-MS) that was
shipped with this manual.
If you need a copy of this supplement, please contact us at the information
provided at the back of this chapter.