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Net-2000™ Voice Codec Unit
User’s Manual
Page 38
Section 3 – Net-2000™ VCU Control
DVSI Confidential Proprietary
Decode Command Packet
The Net-2000™ VCU can receive Decode command packets (Table 25 Decode Command Packet)
from a PC to decode files. Decode packets contain the channel data for one frame of voice and the
control flags and data needed to run the decoder.
Decode Command Packet
Bytes
(msb-lsb)
Bit
7 6 5 4 3 2 1 0
Bit
7 6 5 4 3 2 1 0
Parameter Name
0 - 1
0 0 0 0 0 0 0 0
0 1 1 0 0 0 0 0
len
2 - 3
0 0 0 0 0 0 0 0
0 0 0 0 0 0 1 1
type
Header
4 - 5
x x x x x x x x
x x x x x x x x
seq
6 - 7
0 0 0 0 0 0 0 0
1 1 0 0 0 x x x
rate [0]
8 - 9
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
rate [1]
10 - 11
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
rate [2]
12 - 13
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
rate [3]
14 - 15
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
rate [4]
16 - 17
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
rate [5]
18 - 19
0 x 0 0 0 0 0 0
0 0 0 0 0 0 0 0
cmode
20 - 21
0 0 0 0 0 0 0 0
1 0 x x x x x x
tone.idx
22 - 23
x 0 0 0 0 0 0 0
0 x x x x x x x
tone.amp
24 - 25
0 0 0 0 0 0 0 0
1 0 x x x x x x
ws
26 - 27
0 0 0 0 x x x x
0 0 0 x 0 0 x x
format
28 - 29
x x x x x x x x
x x x x x x x x
channel [0-1]
30 - 31
x x x x x x x x
x x x x x x x x
channel [2-3]
32 - 33
x x x x x x x x
x x x x x x x x
channel [4-5]
… … … …
216-217
x x x x x x x x
x x x x x x x x
channel [190-191]
Table 25 Decode Command Packet
The cmode element of the packet contains the mode flags that enable various features of the
decoder such as tone generation as shown in Table 26 cmode Bits for Decoder Command Packets. If
the cmode element has the AMBE DTMF SEND FLAG bit set to force the decoder to synthesize a
tone, the index and amplitude of the tone to generate are in the tone.idx and tone.amp elements of
the packet, respectively.
The ws element of the packet contains the number of voice samples to be generated by the decoder.
The format element of the packet indicates the format of the voice data to be generated by the
decoder. Appropriate values for tone.idx, tone.amp, ws, and format are listed in Packet Common-
Parameters Section Table 19, Table 20, Table 21 ws -- Channel Parameter.