Grass Valley AMX-3981 2014 - Manual (Page 36)

GUIDE TO INSTALLATION AND OPERATION
30 | AMX-3981
5.4.5 AES Inputs tab
The AMX-3981 processes 32 channels of audio. The
sources of the channels are:
Channels 1-16:
Audio embedded in the incoming SDI
stream
Channels 17-32 Audio from the eight AES inputs on the
rear panel
Each of the rear panel AES inputs is provided with a sample
rate converter that will convert the sample rate of the AES
input to match the sample rate of the audio data embedded
in the incoming SDI stream
5.4.6 Status tab
The Status tab reports the type of audio present at the input
and the Dolby E alignment.
Audio Type Status:
• PCM – the audio channel carries PCM audio (orange)
• Dolby E – the audio channel carries Dolby E encoded
audio (blue)
• AC3 – the audio channel carries Dolby Digital encoded
audio (violet)
• NPCM – the audio channel carries Dolby Digital Plus
or non-PCM other than Dolby E or Dolby Digital
(yellow).
Dolby E Alignment:
• When Dolby E audio is present, this panel will display
the offset/delay between the Dolby E and the video
output timing of the card. You may click the Auto Align
button to automatically adjust the audio timing delay to
ensure a perfect alignment with the video. This is
equivalent to changing manually the audio delay in the
audio processor. If you change the output timing of the
card or the video output format, you may have to re-
align the Dolby E.
• The offset is not available for any type of audio other
than Dolby E.
The measured Dolby E offset can be a positive OR a
negative value. A negative value indicates the Dolby E is in
advance compared to the video and additional delay should
be added to the audio channel pair.
A positive value indicates the Dolby E is late compared to the
video and the audio delay must be reduced for this channel
pair. Sometimes, the audio delay cannot be compensated
because it would mean to have an audio delay lower than the
Figure 5.19 Audio Processing – AES inputs
Figure 5.20 Audio Processing - Status