Ensemble Designs 7550 HD Legalizer - Manual (Page 9)

8415 Audio Processor Configuration
The 8415 Audio Processor accepts audio from the AES input connectors and can disembed
audio from the incoming HD or SD SDI video stream.
Between the input and output is a 8x8 mixer with tracking audio delay. Any incoming
audio can be mixed, level controlled and/or shuffled to another output channel by means
of the integrated audio router. The tracking audio delay allows synchronization and
timing to be maintained with time base corrected video passing through the video frame
synchronizer of the 7550.
A built in sample rate converter allows use of asynchronous AES input signals. The Audio
Processors also support encoded audio formats such as AC-3 and Dolby-E. Because these
data streams cannot tolerate sample rate conversion, they must be input to the Audio
Processors synchronous to the video. All audio processing is performed at the full 24 bit
resolution of the system. At the output side of the submodule the eight audio channels
may be simultaneously routed to AES output connectors while also being embedded on the
outgoing SDI video. An adapter is also available to allow the AES I/O to be converted from
BNC to 110 ohm balanced on the output.
The available audio processing remote control menus are summarized below:
• Audio Mix: This menu gives full access to the 8x8 audio mixer controls. Any input
channel can be routed to any or all output busses. Sliders in Avenue PC or rotary
knobs on a control panel permit levels to be adjusted from -70dB to +12dB.
Alternatively a value can be put in the numeric window, followed by the Enter key,
and this will become the new gain setting. Default buttons are provided for return
to zero level.
The Tie function is used for stereo operation where gain of a pair of channels is
usually desired to be the same. An invert selection allows inversion of a channel to
permit phase correction.
• Audio In: Status indicators show presence of AES and embedded (HD SDI or
SD SDI) audio inputs. The Audio In A and Audio In B menus allow selection of
inputs to the audio mixer. The choices for the 8415 are AES 1/2, AES 3/4, AES 5/6
and AES 7/8 and SDI 1/2, SDI 3/4, SDI 5/6, and SDI 7/8. Thus any pair of input
audio signals can be routed to either pair of input buses of the output audio mixer.
• Audio Mode: The Audio Mode control is provided to allow an SDI input with
embedded audio to operate in Audio (normal) or Data (non-audio). The 7550 can
handle both types of content present in AC-3 or Dolby E signals. Some synchroniz-
ing requirements are necessary for supporting these protocols.
Select the Audio mode when the input audio signal is a standard audio signal
carrying two channels of linear audio. No special timing requirements are needed
in this mode.
Use the Data mode when the serial digital audio is a non-audio, or data, signal.
Some special synchronizing requirements must be observed in this mode as
described in the following examples.
HD or SD SDI Signal with embedded data – For this case, if an SDI
signal with embedded data is applied to the input, the content will be
handled by passing through the 7550 frame store memory to the output of
the 7550. No audio submodule is required. The audio input signal in this
7550-9
Model 7550 HD Video Proc Frame Sync