The following connectors are typically supported by ampmix devices:
MCI_AMP_STREAM_CONNECTOR
MCI_HEADPHONES_CONNECTOR
MCI_LINE_IN_CONNECTOR
MCI_LINE_OUT_CONNECTOR
MCI_MICROPHONE_CONNECTOR
MCI_SPEAKERS_CONNECTOR
The number and type of connectors supported by an audio device varies by manufacturer. To determine which connectors are supported, an application can issue the MCI_CONNECTORINFO message.
The ampmix device provides audio attribute control for individual connectors. An application can set an audio attribute for a connector with MCI_SET by specifying the connector in the ulValue field of the MCI_AMP_SET_PARMS structure. If ulValue contains MCI_AMP_STREAM_CONNECTOR, the setting affects the global output of the device.
An application can query the capabilities of a connector by using the MCI_GETDEVCAPS_EXTENDED message in combination with the MCI_MIXER_LINE flag in the ulExtended field of the MCI_AMP_GETDEVCAPS_PARMS structure. The ulAttribute field contains the audio attribute, and the ulValue field contains the connector whose capabilities you are querying.
The following example illustrates how an application can determine whether it can set the volume for a particular connector.
ULONG rc; /* Return code */MCI_AMP_GETDEVCAPS_PARMS mciAmpCaps; /* Ampmix caps */
USHORT usDeviceID; /* Device ID */
/* Test mixer support for volume changes on the microphone */
mciAmpCaps.ulValue = MCI_MICROPHONE_CONNECTOR;
mciAmpCaps.ulAttribute = MCI_AMP_CAN_SET_VOLUME;
mciAmpCaps.ulExtended = MCI_MIXER_LINE;
rc = mciSendCommand(usDeviceID,
MCI_GETDEVCAPS,
MCI_WAIT|MCI_GETDEVCAPS_EXTENDED,
(ULONG) &mciAmpCaps,
0);