音量调节及静音

在进行多媒体软件开发时，经常要调整各种设备的音量和设置静音，本人编写了一个单元，四个函数，分别用于获取音量（GetVolume(DN))、设置音量(SetVolume(DN,Value))、获取静音（GetVolumeMute(DN)）及设置静音（SetVolumeMute(DN,Value)）。

unit funVolume;

interface

uses MMSystem, Dialogs;

Type TDeviceName = (Master, Microphone, WaveOut, Synth);

function GetVolume(DN:TDeviceName) : Word ;

procedure SetVolume(DN:TDeviceName; Value:Word);

function GetVolumeMute(DN:TDeviceName) : Boolean;

procedure SetVolumeMute(DN:TDeviceName; Value:Boolean);

implementation

//获取音量

function GetVolume(DN:TDeviceName) : Word;

var

hMix: HMIXER;

mxlc: MIXERLINECONTROLS;

mxcd: TMIXERCONTROLDETAILS;

vol: TMIXERCONTROLDETAILS_UNSIGNED;

mxc: MIXERCONTROL;

mxl: TMixerLine;

intRet: Integer;

nMixerDevs: Integer;

begin

// Check if Mixer is available

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

case DN of

Master : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;

Microphone :

mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE;

WaveOut : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT;

Synth : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER;

end;

mxl.cbStruct := SizeOf(mxl);

// get line info

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

if intRet = MMSYSERR_NOERROR then

begin

FillChar(mxlc, SizeOf(mxlc),0);

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

FillChar(mxcd, SizeOf(mxcd),0);

mxcd.dwControlID := mxc.dwControlID;

mxcd.cbStruct := SizeOf(mxcd);

mxcd.cMultipleItems := 0;

mxcd.cbDetails := SizeOf(Vol);

mxcd.paDetails := @vol;

mxcd.cChannels := 1;

intRet := mixerGetControlDetails(hMix, @mxcd,MIXER_SETCONTROLDETAILSF_VALUE);

Result := vol.dwValue ;

if intRet <> MMSYSERR_NOERROR then

ShowMessage('GetControlDetails Error');

end

else

ShowMessage('GetLineInfo Error');

end;

intRet := mixerClose(hMix);

end;

end;

//设置音量

procedure setVolume(DN:TDeviceName; Value : Word);

var

hMix: HMIXER;

mxlc: MIXERLINECONTROLS;

mxcd: TMIXERCONTROLDETAILS;

vol: TMIXERCONTROLDETAILS_UNSIGNED;

mxc: MIXERCONTROL;

mxl: TMixerLine;

intRet: Integer;

nMixerDevs: Integer;

begin

// Check if Mixer is available

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

case DN of

Master : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;

Microphone :

mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE;

WaveOut : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT;

Synth : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER;

end;

mxl.cbStruct := SizeOf(mxl);

// get line info

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

if intRet = MMSYSERR_NOERROR then

begin

FillChar(mxlc, SizeOf(mxlc),0);

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

FillChar(mxcd, SizeOf(mxcd),0);

mxcd.dwControlID := mxc.dwControlID;

mxcd.cbStruct := SizeOf(mxcd);

mxcd.cMultipleItems := 0;

mxcd.cbDetails := SizeOf(Vol);

mxcd.paDetails := @vol;

mxcd.cChannels := 1;

vol.dwValue := Value;

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;

//获取静音

function GetVolumeMute(DN:TDeviceName) : 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

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

case DN of

Master : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;

Microphone :

mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE;

WaveOut : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT;

Synth : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER;

end;

mxl.cbStruct := SizeOf(mxl);

// mixerline info

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

if intRet = MMSYSERR_NOERROR then

begin

FillChar(mxlc, SizeOf(mxlc),0);

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

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

if intRet = MMSYSERR_NOERROR then

begin

FillChar(mxcd, SizeOf(mxcd),0);

mxcd.cbStruct := SizeOf(TMIXERCONTROLDETAILS);

mxcd.dwControlID := mxc.dwControlID;

mxcd.cChannels := 1;

mxcd.cbDetails := SizeOf(MIXERCONTROLDETAILS_BOOLEAN);

mxcd.paDetails := @mcdMute;

// Get mute

intRet := mixerGetControlDetails(hMix, @mxcd, MIXER_SETCONTROLDETAILSF_VALUE);

if mcdMute.fValue = 0 then Result:=false

else Result := True;

if intRet <> MMSYSERR_NOERROR then

ShowMessage('SetControlDetails Error');

end

else

ShowMessage('GetLineInfo Error');

end;

intRet := mixerClose(hMix);

end;

end;

//设置静音

procedure SetVolumeMute(DN:TDeviceName; Value: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

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

case DN of

Master : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;

Microphone :

mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE;

WaveOut : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT;

Synth : mxl.dwComponentType := MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER;

end;

mxl.cbStruct := SizeOf(mxl);

// mixerline info

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

if intRet = MMSYSERR_NOERROR then

begin

FillChar(mxlc, SizeOf(mxlc),0);

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

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

if intRet = MMSYSERR_NOERROR then

begin

FillChar(mxcd, SizeOf(mxcd),0);

mxcd.cbStruct := SizeOf(TMIXERCONTROLDETAILS);

mxcd.dwControlID := mxc.dwControlID;

mxcd.cChannels := 1;

mxcd.cbDetails := SizeOf(MIXERCONTROLDETAILS_BOOLEAN);

mxcd.paDetails := @mcdMute;

// Set and UnSet mute

mcdMute.fValue := Ord(Value);

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;

end.

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