LINEMEDIACONTROL_ Constants

The LINEMEDIACONTROL_ bit-flag constants describe a set of generic operations on media streams. The interpretations are determined by the media stream. The line device must have the media-control capability for any media-control operation to be effective.

LINEMEDIACONTROL_NONE

No change is to be made to the media stream.

LINEMEDIACONTROL_START

Start the media stream.

LINEMEDIACONTROL_RESET

Reset the media stream. Equivalent to an end-of-input. All buffers are released.

LINEMEDIACONTROL_PAUSE

Temporarily pause the media stream.

LINEMEDIACONTROL_RESUME

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.

The high-order 16 bits can be assigned for device-specific extensions. The low-order 16 bits are reserved.

Media control is provided to improve performance of actions on media streams in response to telephony-related events. The application should normally manage a media stream through the media-specific API. The media-control functionality provided here is not intended to replace the native media APIs.

Media-control actions can be associated with the detection of digits, the detection of tones, the transition into a call state, and the detection of a media mode. Consult a line's device capabilities to determine whether media control is available on the line.