Introduction - If you have any usage issues, please Google them yourself
This program is equivalent to the "Mute all" check box of Windows Volume Control for Playback. The Master Mute control is the MIXERCONTROL_CONTROLTYPE_MUTE control of the MIXERLINE_COMPONENTTYPE_DST_SPEAKERS destination audio line. It belongs to the switch controls (MIXERCONTROL_CT_CLASS_SWITCH), which are two-state switches. It uses the MIXERCONTROLDETAILS_BOOLEAN structure to retrieve and set control properties. Whenever the check box is clicked, CMuteDlg::amdSetMasterMuteValue() is called to set the Master Mute value accordingly. The MM_MIXM_CONTROL_CHANGE message is received once the state of the Master Mute control has changed. In this case, CMuteDlg::amdGetMasterMuteValue() is called to retrieve the current value of the Master Mute control and update the state of the check box accordingly.