AudioMixer component of the Wave Audio package supports only Volume, Mute, and Select controls.
However, a solution could be:
- Call mixerGetLineControls with MIXER_GETLINECONTROLSF_ALL flag on microphone line to get all controls of the line.
- In the fetched controls, look for the fader.
- If the fader control found, use mixerGetControlDetails and mixerSetControlDetails to get and set the control's value.
Cheers