Set the volume for the microphone/ mute it

Author: Thomas Stutz

uses

MMSystem;

// Setzt die Lautstärke für das Mikrofon

// Set the volume for the microphone

function SetMicrophoneVolume(bValue: Word): Boolean;

var {0..65535}

hMix: HMIXER;

mxlc: MIXERLINECONTROLS;

mxcd: TMIXERCONTROLDETAILS;

vol: TMIXERCONTROLDETAILS_UNSIGNED;

mxc: MIXERCONTROL;

mxl: TMixerLine;

intRet: Integer;

nMixerDevs: Integer;

begin

// Check if Mixer is available

// Überprüfen, ob ein Mixer vorhanden

nMixerDevs := mixerGetNumDevs();

if (nMixerDevs < 1) then

begin

Exit;

end;

// open the mixer

intRet := mixerOpen(@hMix, 0, 0, 0, 0);

if intRet = MMSYSERR_NOERROR then

begin

mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE;

mxl.cbStruct := SizeOf(mxl);

// get line info

intRet := mixerGetLineInfo(hMix, @mxl, MIXER_GETLINEINFOF_COMPONENTTYPE);

if intRet = MMSYSERR_NOERROR then

begin

ZeroMemory(@mxlc, SizeOf(mxlc));

mxlc.cbStruct := SizeOf(mxlc);

mxlc.dwLineID := mxl.dwLineID;

mxlc.dwControlType := MIXERCONTROL_CONTROLTYPE_VOLUME;

mxlc.cControls := 1;

mxlc.cbmxctrl := SizeOf(mxc);

mxlc.pamxctrl := @mxc;

intRet := mixerGetLineControls(hMix, @mxlc, MIXER_GETLINECONTROLSF_ONEBYTYPE);

if intRet = MMSYSERR_NOERROR then

begin

{

// Microphone Name

Label1.Caption := mxlc.pamxctrl.szName;

// Min/Max Volume

Label2.Caption := IntToStr(mxc.Bounds.dwMinimum) + '->' + IntToStr(mxc.Bounds.dwMaximum);

}

ZeroMemory(@mxcd, SizeOf(mxcd));

mxcd.dwControlID := mxc.dwControlID;

mxcd.cbStruct := SizeOf(mxcd);

mxcd.cMultipleItems := 0;

mxcd.cbDetails := SizeOf(Vol);

mxcd.paDetails := @vol;

mxcd.cChannels := 1;

// vol.dwValue := mxlc.pamxctrl.Bounds.lMinimum; Set min. Volume / Minimum setzen

// vol.dwValue := mxlc.pamxctrl.Bounds.lMaximum; Set max. Volume / Maximum setzen

vol.dwValue := bValue;

intRet := mixerSetControlDetails(hMix, @mxcd,

MIXER_SETCONTROLDETAILSF_VALUE);

if intRet <> MMSYSERR_NOERROR then

ShowMessage('SetControlDetails Error');

end

else

ShowMessage('GetLineInfo Error');

end;

intRet := mixerClose(hMix);

end;

end;

procedure TForm1.Button1Click(Sender: TObject);

begin

SetMicrophoneVolume(30000);

end;

{********************************************************}

// Enable/disable "Mute Microphone Volume"

// Ton für Mikrofon ein/ausschalten

function SetMicrophoneVolumeMute(bMute: Boolean): Boolean;

var

hMix: HMIXER;

mxlc: MIXERLINECONTROLS;

mxcd: TMIXERCONTROLDETAILS;

vol: TMIXERCONTROLDETAILS_UNSIGNED;

mxc: MIXERCONTROL;

mxl: TMixerLine;

intRet: Integer;

nMixerDevs: Integer;

mcdMute: MIXERCONTROLDETAILS_BOOLEAN;

begin

// Check if Mixer is available

// Überprüfen, ob ein Mixer vorhanden ist

nMixerDevs := mixerGetNumDevs();

if (nMixerDevs < 1) then

begin

Exit;

end;

// open the mixer

// Mixer öffnen

intRet := mixerOpen(@hMix, 0, 0, 0, 0);

if intRet = MMSYSERR_NOERROR then

begin

mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE;

mxl.cbStruct := SizeOf(mxl);

// mixerline info

intRet := mixerGetLineInfo(hMix, @mxl, MIXER_GETLINEINFOF_COMPONENTTYPE);

if intRet = MMSYSERR_NOERROR then

begin

ZeroMemory(@mxlc, SizeOf(mxlc));

mxlc.cbStruct := SizeOf(mxlc);

mxlc.dwLineID := mxl.dwLineID;

mxlc.dwControlType := MIXERCONTROL_CONTROLTYPE_MUTE;

mxlc.cControls := 1;

mxlc.cbmxctrl := SizeOf(mxc);

mxlc.pamxctrl := @mxc;

// Get the mute control

// Mute control ermitteln

intRet := mixerGetLineControls(hMix, @mxlc, MIXER_GETLINECONTROLSF_ONEBYTYPE);

if intRet = MMSYSERR_NOERROR then

begin

ZeroMemory(@mxcd, SizeOf(mxcd));

mxcd.cbStruct := SizeOf(TMIXERCONTROLDETAILS);

mxcd.dwControlID := mxc.dwControlID;

mxcd.cChannels := 1;

mxcd.cbDetails := SizeOf(MIXERCONTROLDETAILS_BOOLEAN);

mxcd.paDetails := @mcdMute;

mcdMute.fValue := Ord(bMute);

// set, unset mute

// Stumsschalten ein/aus

intRet := mixerSetControlDetails(hMix, @mxcd,

MIXER_SETCONTROLDETAILSF_VALUE);

{

mixerGetControlDetails(hMix, @mxcd,

MIXER_GETCONTROLDETAILSF_VALUE);

Result := Boolean(mcdMute.fValue);

}

Result := intRet = MMSYSERR_NOERROR;

if intRet <> MMSYSERR_NOERROR then

ShowMessage('SetControlDetails Error');

end

else

ShowMessage('GetLineInfo Error');

end;

intRet := mixerClose(hMix);

end;

end;

procedure TForm1.Button1Click(Sender: TObject);

begin

SetMicrophoneVolumeMute(False);

end;