Grass Valley AMX-3981 2014 - Manual (Page 33)

GUIDE TO INSTALLATION AND OPERATION
AMX-3981 | 27
Without Reference:
Additional Adjustment Adjustment
Frame Delay Range Range
(59.94 Hz) (50 Hz)
1 -12 to 2000 ms -19 to 2000 ms
2 -45 to 2000 ms -59 to 2000 ms
3 -78 to 2000 ms -99 to 2000 ms
… … …
15 -479 to 2000 ms -579 to 2000 ms
• Fine – adjusts the delay in audio sample increments, from -100 to +100 samples.
5.4.3 Audio Proc – Silence tab
This tab sets the card’s behavior in the event of a loss or
absence of audio signal. The Signal Presence indicators are
then triggered according to these settings:
Silence Detect: select which audio channels to monitor for
audio silences by checking their boxes. This enables the
signal presence indicators to change color when there is no
signal present which activates the audio silence alarm.
Otherwise, when checkboxes are not checked, the signal
presence indicator turns grey and the audio silence alarm is
not activated
Threshold: Signal absence is declared when the signal level
is lower than the signal threshold for a duration longer than
the No Signal Delay. The threshold can be set to -72, -66,
-60, -54, -48 dBFS. The default value is –60 dBFS.
No Signal Delay: The period for which signal must be
continuously absent before an alarm can be triggered can be
adjusted from 3 to 255 seconds in preset steps: 3, 5, 7, 10,
15, 20, 30, 40, 50, 60, 90, 120, 180, 210, 240, 255 sec. The
default value is set to 15 seconds.
5.4.4 Downmix
This tab provides resources to control the downmix of a “5.1 channel” surround-sound audio signal into an LtRt or
LoRo stereo pair. The 5.1 terminology refers to six discrete audio channels, with the low frequency effect (LFE)
channel of limited bandwidth designated as the “.1” channel. The downmix can be done using any of the 32 audio
channels processed by the audio processor using the Input Channels controls in the interface.
Input Channels: Use the 6 pulldowns to select the source channels for the downmix process.
Downmix:
Operating Mode: Use the pulldown list to select the downmix operating mode:
• OFF: Downmix is disabled. Output channels pass through unchanged.
• Manual: Downmix follows the downmix parameters manually configured by the user.
• Follow Metadata: Downmix follows the downmix parameters of the Metadata.
Figure 5.15 Audio Processing - Channels – Silence