Audio And Data Interfaces - Cisco D9040 User And Service Manual

Audio and Data Interfaces

Audio Input
Four audio stereo channels can be input at the D9040 Encoder. Each of the audio
channels can be sourced from analog, digital AES-3id or embedded SDI audio
sources. You can assign the encoded audio channels to the video program or to
independent audio only programs.
Digital Audio Interface
The audio input interface accepts a digital input, formatted as an AES/EBU
encoded signal. Left and right channel samples are extracted from the input and
synchronized to the video signal.
Analog Audio Interface
The audio input interface features balanced left and right analog inputs. For each
analog audio input you can set the input impedance and the clipping level.
Embedded Audio
The audio input interface can be configured to accept an input of embedded audio
from the SDI video input interface.
Audio Encoding Formats
The supported audio encoding formats are MPEG-1 layer II, Dolby Digital,
passthrough of Dolby Digital, andAAC.
Layer II Encoding
The audio inputs may be encoded in the following ways:
• a stereo program
• a joint stereo program
• two independent mono programs
• Dual channel
You can set the sampling frequency for the digitizing process to one of the
following values:
• 32 kHz
• 44.1 kHz
• 48 kHz.
For audio attached to the video the D9040 Encoder locks the audio sampling
frequency to the video. For AES/EBU digital input signals, the D9040 Encoder
automatically adapts the incoming rate by using sample rate conversion.
2-8 Introduction
4020024 Rev C