lineSetCallParams
The lineSetCallParams
function allows an application to change bearer mode and/or the rate parameters
of an existing call.
LONG lineSetCallParams(
HCALL hCall, |
|
DWORD dwBearerMode, |
|
DWORD dwMinRate, |
|
DWORD dwMaxRate, |
|
LPLINEDIALPARAMS const lpDialParams |
|
); |
|
Parameters
hCall
A handle to
the call whose parameters are to be changed. The application must be an owner
of the call. The call state of hCall can be any state except idle
and disconnected.
dwBearerMode
The new
bearer mode for the call. This parameter can have only a single bit set, and it
uses the following LINEBEARERMODE_ constants:
LINEBEARERMODE_VOICE
A regular 3.1
kHz analog voice-grade bearer service. Bit integrity is not assured. Voice can
support fax and modem media modes.
LINEBEARERMODE_SPEECH
This
corresponds to G.711 speech transmission on the call. The network may use
processing techniques such as analog transmission, echo cancellation, and
compression/decompression. Bit integrity is not assured. Speech is not intended
to support fax and modem media modes.
LINEBEARERMODE_MULTIUSE
The multi-use
mode defined by ISDN.
LINEBEARERMODE_DATA
The unrestricted
data transfer on the call. The data rate is specified separately.
LINEBEARERMODE_ALTSPEECHDATA
The alternate
transfer of speech or unrestricted data on the same call (ISDN).
LINEBEARERMODE_NONCALLSIGNALING
Corresponds
to a non-call-associated signaling connection from the application to the
service provider or switch (treated as a media stream by the Telephony API).
LINEBEARERMODE_PASSTHROUGH
When a call
is active in LINEBEARERMODE_PASSTHROUGH, the service provider gives direct
access to the attached hardware for control by the application. This mode is
used primarily by applications desiring temporary direct control over
asynchronous modems, accessed through the Win32 comm functions, for the purpose
of configuring or using special features not otherwise supported by the service
provider.
dwMinRate
A lower bound
for the call's new data rate. The application is willing to accept a new rate
as low as this one.
dwMaxRate
An upper
bound for the call's new data rate. This is the maximum data rate the application
can accept. If an exact data rate is required, dwMinRate and dwMaxRate
should be equal.
lpDialParams
A pointer to
the new dial parameters for the call, of type LINEDIALPARAMS
Return Values
Returns a
positive request ID if the function will be completed asynchronously, or a
negative error number if an error has occurred. The dwParam2 parameter
of the corresponding LINE_REPLY
LINEERR_BEARERMODEUNAVAIL,
LINEERR_NOTOWNER, LINEERR_INVALBEARERMODE, LINEERR_OPERATIONUNAVAIL,
LINEERR_INVALCALLHANDLE, LINEERR_OPERATIONFAILED, LINEERR_INVALCALLSTATE,
LINEERR_RATEUNAVAIL, LINEERR_INVALPOINTER, LINEERR_RESOURCEUNAVAIL,
LINEERR_INVALRATE, LINEERR_UNINITIALIZED, LINEERR_NOMEM.
Remarks
This operation
is used to change the parameters of an existing call. Examples of its usage include
changing the bearer mode and/or the data rate of an existing call.
See Also