User`s manual

VC-55™ PR Voice Codec Board
User’s Manual
Version 1.3
Section 3 – Set-up & Control
Page 11
DVSI Confidential Proprietary
quality audio output.
-m
Chan_Rx_Min_Time
Between
0-636
Jitter Buffer Minimum time This time is
adjustable to compensate for jitter on the
channel interface. The minimum buffer time
can be set between 0 and 636 ms. The
option is set by multpling the desired delay by
4000 (ex. A 1ms delay is set using the
variable 4)
-M
Chan_Rx_Max_Time
Between
4-640
Jitter Buffer Maximum time This time is
adjustable to compensate for jitter on the
channel interface. The maximum buffer time
can be set between 4 and 640 ms. The
option is set by multpling the desired delay by
4000 (ex. A 100ms delay is set using the
variable 400)
Vocoder Options
[f]ull-rate
(default)
The vocoder has a total data bit rate of
7200 bps. Of these bits 4400 bps is
voice data and 2800 bps is Forward
Error Correction (FEC).
-r
Vocoder Rate
[h]alf-rate
The Half-Rate vocoder in the VC-55™-
PR Vocoder Board has a total data rate
of 3600 bps. The Half-Rate includes
2450 bps of data and 1150 bps of FEC
0
The [0] value sets VC-55 board to run
the vocoder rate as defined in the –r
option of the vc55param program. If no
–r option is included in the run
command then the vocoder rate will be
set to what is stored in Flash memory.
-p
Encoder_Mode_Pin_Enable
1
The [1] value sets VC-55 board to run
the vocoder rate as defined by the rate
pin (no. 23 on J7). The pin default (no
connection) is set to run the vocoder in
half-rate mode.
-t
Side_Tone
default = -12dB, valid values= -6, -9, -
12, -15, or -100 for off
Note: Side Tone is used when a handset is
connected to the VC-55. It sends a portion of the
input signal from the microphone to the speaker
of the handset to prevent the handset from
sounding "dead".
0 Disables both NS and DTX
64
NS ENABLE FLAG
Enables noise suppression in the
encoder.
2048
DTX ENABLE FLAG
Enables silence frame generation in the
encoder.
-e
EncodeCmode
2112
NS and DTX Enables both noise