7700 MultiFrame Manual
7736CEM Composite Encoder with Monitoring
Page - 52
Revision 1.5
*Grey background indicates un-implemented or un-tested features
7.11.6. Detecting Audio Silence Faults
The
Silence level
and
Silence duration
controls are used to detect when the audio is considered to be
silent. The
Silence level
control sets the audio level under which the audio is considered to be silent. The
audio must be under the
Silence level
for the duration set by the
Silence duration
control before the fault
condition exists. When the fault condition exists, the audio must be over the
Silence level
for the duration
set by the
Silence duration
control before the fault condition will be removed. A fault will be generated
when both channels in a pair (1 and 2 or 3 and 4) has satisfied a silence condition.
7.11.6.1. Setting the Audio Silence Level
Fault definitions
This control sets the audio level under which it is considered to be
silent. This value is expressed in dB full scale (FS)
Silence level
-96dB to –20dB FS
-60dB FS
7.11.6.2. Setting the Audio Silence Duration
Fault definitions
This control sets the amount of time the audio is silent in seconds
before a fault occurs.
Silence duration
0.5 to 127 sec
10 sec
7.11.7. Detecting Audio Phase Reversal Faults
All stereo audio material has a varying amount of phase difference between the two channels. If there is
significant phase reversal for a period of time, then this is a sign that the audio signals may be out of
phase.
The
Phase reversal level
and
Phase reversal duration
controls are used to detect when the left and right
audio channels are considered to be out of phase. The
Phase reversal level
control sets the amount of
phase difference that is considered to be out of phase. The audio must be out of phase by more than the
Phase reversal level
amount for the duration set by the
Phase reversal duration
control before the fault
condition exists. When the fault condition is active, the audio must be out of phase by less than the
Phase
reversal level
amount for the duration set by the
Phase reversal duration
control before the fault condition
will be removed.
7.11.7.1. Setting the Audio Phase Reversal Level
Fault definitions
This control sets the amount of phase difference before the audio is
considered to be out of phase. This phase reversal is calculated by
comparing the difference of the two channels to the average of the
two. If a signal is always out of phase, then the difference between
the two will be high compared to the average of the two. This
corresponds to 1 in this control.
If there is only content on one of the channels (i.e. left only or right
only), then the difference is equivalent to the average of the two
channels. This corresponds to 0.5 in this control.
Phase reversal level
0.5 to 1 in 0.01
increments
0.9
