AAV-DMUX
Rev. 1
5 Configuration
270 Mbit digital video may have up to four audio groups which are numbered 1 to
4. Each audio group has four mono audio channels or two stereo audio signals. The
AAV-DMUX works with a single audio group. Digital VTRs usually embed audio in
group 1.
5.1 DIP switches
The configuration of the card sets a number of parameters: -
The output gain for the D/A converters.
The audio group number to be de-embedded.
Whether to remove the audio group from the SDI signal.
Whether EDH information is inserted into the output SDI video.
5.1.1 Output gain
The D/A converter has a defined maximum level which can be configured with the
gain switches.
The card has two eight-way miniature DIP switches on the card. Groups of 3 switches
control the gains of each of the analogue outputs. Switches marked 1L and 1R
control the levels for converter 1 while switches marked 2L and 2R control the levels
for converter 2. The settings for the level switches are presented in the following
table. The table is also printed on the AAV-DMUX card.
0 corresponds to off.
1 corresponds to on.
The three numbers in the top row should be read as: S2,S1,S0.
Switches
111
011
101
001
110
010 100 000
dBu @ 0 dBFS
23.9
23
21.4 20.1 19.7
18
15
12
Example: S0 and S2 off, S1 on gives a maximum input level of +18 dBu. (see figure
on the next page)
5.1.2 No EDH insert
This switch is used to select whether the de-embedder processor inserts a new EDH
packet into the output video if EDH was not present on the input. The card cannot
remove an EDH packet if it is already present. Existing EDH packets are always
updated. Some old video equipment cannot tolerate the presence of EDH.
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