Multi-Tech Systems MT5634SMI V.92 ユーザーズマニュアル
Chapter 4 – Voice Commands
Multi-Tech Systems, Inc. SocketModem MT5634SMIxx Reference Guide (S000263C)
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Command +VSM=<cml>,<vsr>,<scs>,<sel> Select Voice Compression Method
Values:
(see individual parameter descriptions)
Default:
(see individual parameter descriptions)
Result Codes: OK if the modem accepts the command; ERROR if one or more of the following apply: 1)
the any parameter entered is out of range, or 2) any of the four parameters are missing
from the command string. If an error occurs, the modem retains the previous <sds> and
<sdi> parameter values.
from the command string. If an error occurs, the modem retains the previous <sds> and
<sdi> parameter values.
Description:
The +VSM= command sets the modem to a specified voice compression method, silence
compression sensitivity, and voice sampling rate. The modem can maintain a different
event detection capability for each compression method. This command allows the PC to
set the amount of silence compression appropriate to a particular situation or application.
For example, you may want to record your welcome message with the lowest amount of
silence removal, with the goal of reducing distortion, meanwhile recording other
messages with a more assertive silence removal, to limit disk space used for recording
purposes.
compression sensitivity, and voice sampling rate. The modem can maintain a different
event detection capability for each compression method. This command allows the PC to
set the amount of silence compression appropriate to a particular situation or application.
For example, you may want to record your welcome message with the lowest amount of
silence removal, with the goal of reducing distortion, meanwhile recording other
messages with a more assertive silence removal, to limit disk space used for recording
purposes.
The parameter meanings are described below.
<cml> is used by the PC to select a compression method. The valid range of values is
from 128–256. The range of values from 0–127 is reserved for future standards.
from 128–256. The range of values from 0–127 is reserved for future standards.
<vsr> is used to select the modem voice sampling rate from the set of those supported.
The unit of measure is samples per second. See the +VSM=? command for the list of
sampling rates supported by the modem.
The unit of measure is samples per second. See the +VSM=? command for the list of
sampling rates supported by the modem.
<scs> has different meanings in voice transmit and voice receive modes. In receive, the
PC uses <scs> to select greater amounts of compression activity; larger <scs> values
mean that the PC wants the modem to treat noisier conditions as silence. There is no unit
of measure for this parameter; it merely represents a number in a range. 0 disables
modem silence compression.
PC uses <scs> to select greater amounts of compression activity; larger <scs> values
mean that the PC wants the modem to treat noisier conditions as silence. There is no unit
of measure for this parameter; it merely represents a number in a range. 0 disables
modem silence compression.
In voice transmit mode, the PC signals the modem that the data stream was recorded
with silence compression by selecting a non-zero value from within the valid range (the
same value as receive). Unpredictable results can occur if you 1) enable silence
compression for transmitting a voice data stream that was not recorded with silence
compression enabled, or 2) you disable silence compression for transmitting a voice data
stream that was recorded with silence compression enabled. You can modify the silence
expansion with the <sel> parameter. The range of valid values is 0–255. The modem
may limit silence compression sensitivity to a narrower range (e.g., 120–128). A setting of
<scs>=0 disables silence compression.
with silence compression by selecting a non-zero value from within the valid range (the
same value as receive). Unpredictable results can occur if you 1) enable silence
compression for transmitting a voice data stream that was not recorded with silence
compression enabled, or 2) you disable silence compression for transmitting a voice data
stream that was recorded with silence compression enabled. You can modify the silence
expansion with the <sel> parameter. The range of valid values is 0–255. The modem
may limit silence compression sensitivity to a narrower range (e.g., 120–128). A setting of
<scs>=0 disables silence compression.
<sel> is used to modify the amount of silence expansion. This parameter represents the
minimum amount of silence that the modem will expand a period of silence that was
previously deleted with a non-zero <sel> parameter. A setting of <sel>=0 means the
modem will not modify the silence expansion. The valid range of values is ____ - ____ in
0.1second increments. The modem ignores the <sel> parameter if the <scs> parameter
is 0 (silence compression disabled).
minimum amount of silence that the modem will expand a period of silence that was
previously deleted with a non-zero <sel> parameter. A setting of <sel>=0 means the
modem will not modify the silence expansion. The valid range of values is ____ - ____ in
0.1second increments. The modem ignores the <sel> parameter if the <scs> parameter
is 0 (silence compression disabled).