LINE_MONITORMEDIA

The LINE_MONITORMEDIA message is sent when a change in the call's media mode is detected. The sending of this message is controlled with the lineMonitorMedia function.

LINE_MONITORMEDIA
dwDevice = (DWORD) hCall;
dwCallbackInstance = (DWORD) hCallback;
dwParam1 = (DWORD) MediaMode;
dwParam2 = (DWORD) 0;
dwParam3 = (DWORD) 0;
 

Parameters

dwDevice

A handle to the call.

dwCallbackInstance

The callback instance supplied when opening the line.

dwParam1

The new media mode. This parameter must be one and only one of the following LINEMEDIAMODE_ constants:

LINEMEDIAMODE_INTERACTIVEVOICE

The presence of voice energy has been detected and the call is treated as an interactive call with humans on both ends.

LINEMEDIAMODE_AUTOMATEDVOICE

The presence of voice energy has been detected and the call is locally handled by an automated application.

LINEMEDIAMODE_DATAMODEM

A data modem session has been detected.

LINEMEDIAMODE_G3FAX

A group 3 fax has been detected.

LINEMEDIAMODE_G4FAX

A group 4 fax has been detected.

LINEMEDIAMODE_TDD

A TDD (Telephony Devices for the Deaf) session has been detected.

LINEMEDIAMODE_DIGITALDATA

Digital data has been detected.

LINEMEDIAMODE_TELETEX

A teletex session has been detected. Teletex is one of the telematic services.

LINEMEDIAMODE_VIDEOTEX

A videotex session has been detected. Videotex is one the telematic services.

LINEMEDIAMODE_TELEX

A telex session has been detected. Telex is one the telematic services.

LINEMEDIAMODE_MIXED

A mixed session has been detected. Mixed is one the telematic services.

LINEMEDIAMODE_ADSI

An ADSI (Analog Display Services Interface) session has been detected.

LINEMEDIAMODE_VOICEVIEW

The media mode of the call is VoiceView.

dwParam2

Unused.

dwParam3

The "tick count" (number of milliseconds since Windows started) at which the specified media was detected. For API versions earlier than 2.0, this parameter is unused.

Return Values

No return value.

Remarks

The LINE_MONITORMEDIA message is sent to the application that has enabled media monitoring for the media mode detected.

Because this timestamp may have been generated on a computer other than the one on which the application is executing, it is useful only for comparison to other similarly timestamped messages generated on the same line device (LINE_GATHERDIGITS, LINE_GENERATE, LINE_MONITORDIGITS, LINE_MONITORTONE), in order to determine their relative timing (separation between events). The tick count can "wrap around" after approximately 49.7 days; applications must take this into account when performing calculations.

If the service provider does not generate the timestamp (for example, if it was created using an earlier version of TAPI), then TAPI provides a timestamp at the point closest to the service provider generating the event so that the synthesized timestamp is as accurate as possible.

QuickInfo

  Version: Use TAPI version 1.4 and later.
  Header: Declared in tapi.h.

See Also

LINE_GATHERDIGITS, LINE_GENERATE, LINE_MONITORDIGITS, LINE_MONITORTONE