EN-31
Audio
The
8
pairs
of
Audio
are
divided
equally
between
each
Service
(4
pairs
each).
● There
are
4
AES
inputs.
These
inputs
are
hard-wired
to
the
following
configuration
○ AES
Input
1
→
Service
1,
Audio
1
○ AES
Input
2
→
Service
1,
Audio
2
○ AES
Input
3
→
Service
2,
Audio
1
○ AES
Input
4
→
Service
2,
Audio
2
● Analog
Audio
input
is
hard-wired
to
the
following
DB9
pinout:
PIN
1
2
3
4
5
6
7
8
9
Signal
+L
A1
-L
A1
Gnd
-R
A1
+R
A1
+L
A2
-L
A2
-R
A2
+R
A2
● Audio
3
and
Audio
4
can
only
be
set
to
SDI
input
for
both
services
● Passthru
is
only
an
option
for
Audio
1
and
Audio
2
for
both
services
● The
audio
resources
are
divided
50/50
between
Service
1
and
Service
2
○
Even
if
Service
2
is
set
to
OFF,
Service
1
can
still
only
allocate
50%
of
the
Audio
resources
Encoding:
The
EN-31
has
the
following
Audio
Encoding
capabilities
and
resources.
Different
CODECs
require
a
different
amount
of
resources.
The
EN-31
has
logic
built-in
so
that
the
user
cannot
exceed
the
audio
resources.
CODEC
MODE
%
Usage
per
Pair
MPEG1(2)
Layer
2
--
MU
Stereo
9%
Dolby
Digital
AC3
(x06
&
x81)
--
DD
2/0
14%
AAC-LC
2/0
19%
AAC-HEv1
2/0
17%
AAC-HEv2
2/0
12%
Surround
CODEC
Dolby
Digital
AC3
(x06
&
x81)
--
DD
5/1
29%
AAC-HEv1
5/1
36%
AAC-LC
5/1
38%
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