Date printed: 24.01.12
46
D21m System
6.3.5 3G SdI Input Card
(
and
) A949.0452
The 3G/HD/SD SDI (serial digital interface) 16-channel de-embedder card
is able to de-embed eight or 16 audio channels from SDI-SD as well as from
SDI-HD and 3G (full HD) video streams. For the D21m I/O system it acts as
an eight- or 16-channel audio input card. These two modes are determined
by DIP switches located on the card.
The SDI standard defines up to 16 audio channels transmitted within a video
signal. These 16 channels are divided into four groups of four each. The user
can determine by hardware switches whether all four groups, or only groups
1&2, or only groups 3&4 will be de-embedded.
The card hosts SRCs (sampling rate converters) that are bypassed per default.
When bypassed, the SDI card is fully compatible to receiving embedded
Dolby® E audio data. The SRCs can be enabled in case the audio extracted
from the SDI stream is not in sync with the local system. This means that the
mixing console can run fully independent of the video sync used for SDI.
If the SRCs are bypassed, the card works at a sampling rate of 48 kHz only.
SRC Delay
Enabled input and output SRCs each cause a delay (D) that depends on the
SRC’s input and output sampling rate (f
S_IN
and f
S_OUT
). Input and output delays
can be calculated using the following formulas.
[2]
f
S_OUT
> f
S_IN
:
D =
48
f
S_IN
[s]
[1]
f
S_IN
> f
S_OUT
:
D =
16
f
S_IN
+
[s]
32
f
S_OUT
Examples: For a 96 kHz input signal and a 48 kHz system clock (i.e., the ‘output signal’
of the input SRC), input delay is 40 output samples or 0.833 ms (formula [1]).
For a 48 kHz system clock (i.e., the ‘input signal’ of the output SRC) and a
96 kHz output signal, output delay is 96 output samples or 1 ms (formula [2]).
Operating modes
8- or 16-ch console input (de-embedder)
Selectable SDI groups
1&2, 3&4, or all
Connectors
IN, THROUGH (BNC, 75
Ω
)
Cable length
max. 50 m
Latency*
(de-embedder) < 360 µs + D (D = SRC delay if active; s. above)
Current consumption
(5 V)
0.9 A
Operating temperature
0-40 °C
*
Audio latency times are identical for all channels and all groups.
SD/HD/
3G In
PLL
48 kHz
16 x SRC
Settings
Status
De-Embedder
RX
16
Master Clk
Audio In
Grp1...4
Bypass
Bypass
Grp Select
In Clk
Out Clk
Status
Clk
SDI
ID
Audio In
Grp1...4
Slave Clk
SD/HD/
3G Thru
SDI De-Embedder Module
Backplane Connector
Selector
