Nevion UDC-3G-XMUX4+ - Manual (Page 40)

UDC-3G-XMUX4+ Rev. C
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3.19 AES I/O
The directions of the four AES ports can be selected individually by the user. This means that
the user has any combination of inputs and outputs available: 4 inputs, 3 inputs plus 1
output, 2 inputs + 2 outputs, 1 input + 3 outputs, or 4 outputs.
3.19.1 Audio inputs
When an AES I/O port is set to be an input, the sample frequency of the input is monitored to
see if the signal is synchronous with the system clock. If not, the audio input is passed
through a sample-rate converter. After the input block the audio can be delayed with a delay
individual for each AES port, before it is routed to the audio matrix. The audio delay for AES
inputs are set relative to the AES input port.
If the AES input port is synchronous with the SDI-input, the user can select the AES input
delay to track to the video delay. The card will then calculate the relative delay for the audio
based on the delay setting for video and audio. This is useful if the SDI-in and AES has a
common clock source and the sync input has a different clock source.
3.19.2 Audio outputs
The AES outputs are routed from the audio matrix via individual audio processing blocks.
The outputs are always 48kHz and synchronous to the system clock. The AES outputs have
individual fallback options.
3.20 Audio generator
The stereo audio generator is available in the audio cross point matrix as a source. It is a
high purity 1 kHz sine wave with a 250ms interruption on the left channel every 3 seconds.
The audio level may be set to one of two standards. The two levels are -18 dBFS and -20
dBFS. These two levels correspond to EBU R68 and SMPTE RP 155.
3.21 Audio processing block
The output of each stereo signal from the audio cross point matrix may be processed in the
audio processing block. This is controlled with the Multicon GYDA controller. The processing
includes channel L/R manipulation and audio gain.