Audio And Data Interfaces - Cisco D9054 Installation And Operation Manual

Audio and Data Interfaces

Audio Input
Four audio stereo channels can be input at the D9054 HD Encoder. Each of the
audio inputs accept digital AES/EBU or embedded audio. You can assign the
encoded audio channels, in multiples of two, 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.
Embedded Audio
The audio input interface can be configured to accept an input of embedded audio
from the HD-SDI video input interface.
Audio Encoding Formats
The supported audio encoding formats are MPEG-1 layer II, Dolby Digital, Dolby
Digital passthrough, AAC, or AAC passthrough.
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 D9054 HD Encoder locks the audio sampling
frequency to the video. For AES/EBU digital input signals, the D9054 HD Encoder
automatically adapts the incoming rate by using sample rate conversion. Audio
only programs are locked to a free-running internal 27 MHz clock.
4038938 Rev A D9054 HDTV Encoder Intstallation and Operation Guide 2-7