谁能说说怎样调节音量？？

[boatzm]

我这儿有个函数但不清楚 各参数的意义，那个大哥解释下哈？

//音量控制
procedure TForm1.TrackBar1Change(Sender: TObject);
var
t,v:Longint;
begin
t:=TrackBar1.Position;
v:=(t shl 8)or(t shl 24);
waveOutSetVolume(0,v);
end;

就是 waveOutSetVolume(0,v); 0 和v 是代表什么？？
v:=(t shl 8)or(t shl 24); shl 是？？？

[yingshang]

这是上个世纪的老函数了，不行了！我写了一段，你用用看！

{*******************************************************************}
{ }
{ 音量调节模块： }
{ 1. 获得音量（左右声道）的值和是否静音； }
{ 2. 设置音量（左右声道）的值和是否静音。 }
{ }
{*******************************************************************}

unit VolumeUnit;

interface

uses
// BasicUnit
SysUtils,
MMSystem,
Dialogs;


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

// 获得混音器参数
procedure GetVolume(DN: TDeviceName);
// 设置混音器参数
procedure SetVolume(DN: TDeviceName);


implementation

var
MuteVol : Boolean; // 静音
LeftVol : Integer; // 左声道
RightVol: Integer; // 右声道


{--- 获取声音的所有参数 ------------------------------------------------}
procedure GetVolume(DN: TDeviceName);
var
intRet : Integer;
hMix : HMIXER;
mxl : TMixerLine;
mxc : MIXERCONTROL;
mxlc : MIXERLINECONTROLS;
mxcd : TMIXERCONTROLDETAILS;
details : array [0..30] of Integer;
mcdMute : MIXERCONTROLDETAILS_BOOLEAN;
nMixerDevs: Integer;
begin

// 检查混音器是否可用
nMixerDevs := mixerGetNumDevs();
if (nMixerDevs < 1) then
begin
Exit;
end;

// 打开混音器
intRet := mixerOpen(@hMix, 0, 0, 0, 0);


// 获得左右声道的值
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);

// 获得控制器的信息
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(Integer);
mxcd.paDetails := @details;
mxcd.cChannels := 2;

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

LeftVol := details[0];
RightVol := details[1];

if intRet <> MMSYSERR_NOERROR then
ShowMessage('设置控制器参数错误！');
end
else
ShowMessage('获得控制器信息错误！');
end; // end 左右声道


// 获得静音值
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;

// 获得静音控制器
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;

// 获得静音值
intRet := mixerGetControlDetails(hMix, @mxcd, MIXER_SETCONTROLDETAILSF_VALUE);

if mcdMute.fValue = 0 then
MuteVol := false
else
MuteVol := True;

if intRet <> MMSYSERR_NOERROR then
ShowMessage('设置控制器参数错误！');
end
else
ShowMessage('获得控制器信息错误！');
end; // end 静音

// 关闭混音器
intRet := mixerClose(hMix);
end;
end;

{--- 设置声音的所有参数 ------------------------------------------------}
procedure setVolume(DN: TDeviceName);
var
intRet : Integer;
hMix : HMIXER;
mxl : TMixerLine;
mxc : MIXERCONTROL;
mxlc : MIXERLINECONTROLS;
mxcd : TMIXERCONTROLDETAILS;
details : array [0..30] of Integer;
mcdMute : MIXERCONTROLDETAILS_BOOLEAN;
nMixerDevs: Integer;
begin

// 检查混音器是否可用
nMixerDevs := mixerGetNumDevs();
if (nMixerDevs < 1) then
begin
Exit;
end;

// 打开混音器
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);

// 获得控制器的信息
intRet := mixerGetLineInfo(hMix, @mxl, MIXER_GETLINEINFOF_COMPONENTTYPE);


// 设置左右声道音量
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(Integer);
mxcd.paDetails := @details;
mxcd.cChannels := 2;

details[0] := LeftVol;
details[1] := RightVol;

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

if intRet <> MMSYSERR_NOERROR then
ShowMessage('设置控制器参数错误！');
end
else
ShowMessage('获得控制器信息错误！');
end; // end 左右声道


// 设置静音
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;

// 获得静音控制器
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;

// 设置静音
mcdMute.fValue := Ord(MuteVol);
intRet := mixerSetControlDetails(hMix, @mxcd, MIXER_SETCONTROLDETAILSF_VALUE);

if intRet <> MMSYSERR_NOERROR then
ShowMessage('设置控制器参数错误！');
end
else
ShowMessage('获得控制器信息错误！');
end; // end 静音

// 关闭混音器
intRet := mixerClose(hMix);
end;
end;

end.