LINEMEDIACONTROLTONE

The LINEMEDIACONTROLTONE structure describes a media action to be executed when a tone is detected. It is used as as entry in an array.

typedef struct linemediacontroltone_tag {
    DWORD  dwAppSpecific;
    DWORD  dwDuration;
    DWORD  dwFrequency1;
    DWORD  dwFrequency2;
    DWORD  dwFrequency3;
    DWORD  dwMediaControl;
} LINEMEDIACONTROLTONE, FAR *LPLINEMEDIACONTROLTONE;
 

Members

dwAppSpecific

Used by the application for tagging the tone. When this tone is detected, the value of the dwAppSpecific member is passed back to the application.

dwDuration

The duration in milliseconds during which the tone is present before a detection is made.

dwFrequency1

dwFrequency2

dwFrequency3

The frequency in hertz of a component of the tone. If fewer than three frequencies are needed in the tone, a value of zero should be used for the unused frequencies. A tone with all three frequencies set to zero is interpreted as silence, and can be used for silence detection.

dwMediaControl

The media control action, of type LINEMEDIACONTROL_. Values are:

LINEMEDIACONTROL_NONE

Make no change to the media stream.

LINEMEDIACONTROL_START

Start the media stream.

LINEMEDIACONTROL_RESET

Reset the media stream. Provide the effect of an end of input. All buffers are released.

LINEMEDIACONTROL_PAUSE

Temporarily pause the media stream.

LINEMEDIACONTROL_RESUME

Start or resume a paused media stream.

LINEMEDIACONTROL_RATEUP

The speed of the media stream is increased by some stream-defined quantity.

LINEMEDIACONTROL_RATEDOWN

The speed of the media stream is decreased by some stream-defined quantity.

LINEMEDIACONTROL_RATENORMAL

The speed of the media stream is returned to normal.

LINEMEDIACONTROL_VOLUMEUP

The amplitude of the media stream is increased by some stream-defined quantity.

LINEMEDIACONTROL_VOLUMEDOWN

The amplitude of the media stream is decreased by some stream-defined quantity.

LINEMEDIACONTROL_VOLUMENORMAL

The amplitude of the media stream is returned to normal.

Remarks

Not extensible.

The LINEMEDIACONTROLTONE structure defines a tuple <tone, media control action>. An array of these tuples is passed to the TSPI_lineSetMediaControl function to set media control actions triggered by media mode changes for a given call. When a change to a listed media mode is detected, the corresponding action on the media stream is invoked.

A tone with all frequencies set to zero corresponds to silence. An application can thus monitor the call's information stream for silence.

See Also

LINEMEDIACONTROL_ Constants, TSPI_lineSetMediaControl