Inside Macintosh: Sound /

Chapter 6 - Audio Components / Audio Components Reference

Audio Component-Defined Routines / Getting and Setting Volumes

AudioSetVolume

An audio component can implement the AudioSetVolume function. The Sound Manager calls this function to set the current volume of an audio port.

pascal ComponentResult AudioSetVolume (ComponentInstance ac, 
                                          short whichChannel, 
                                          ShortFixed volume);

ac

A component instance that identifies your audio component.

whichChannel

The channel or channels whose volume you should set.

volume

The desired volume level of the specified channel.

DESCRIPTION

Your AudioSetVolume function is called by the Sound Manager to set the volume levels of one or more channels of an audio port. See the description of the AudioGetVolume function for the values of the whichChannel and volume parameters.

RESULT CODES

Your AudioSetVolume function should return noErr if successful or an appropriate result code otherwise. In particular, if your audio component doesn't support software control of volume levels, AudioSetVolume should return unImpErr.