调节系统音量(话筒)

#include <mmsystem.h>

// 调节系统音量

//--------------------------------------------------------------------------
//  文件： VloControl.cpp    （seeker  modify 2006.08.10）
//  函数： SetVolume(int AudioIndex,long NewPos);
//  参数： AudioIndex 是音频设备的序列，默认的设备就是0
//  参数： NewPos： 音量大小，1--100之间
//WINMM.LIB
//---------------------------------------------------------------------------
bool GetVolumeControl(HMIXER hmixer ,long componentType,long ctrlType,MIXERCONTROL* mxc)
{
   MIXERLINECONTROLS mxlc;
   MIXERLINE mxl;
   mxl.cbStruct = sizeof(mxl);
   mxl.dwComponentType = componentType;
   if(!mixerGetLineInfo((HMIXEROBJ)hmixer, &mxl, MIXER_GETLINEINFOF_COMPONENTTYPE))
   {
      mxlc.cbStruct = sizeof(mxlc);
      mxlc.dwLineID = mxl.dwLineID;
      mxlc.dwControlType = ctrlType;
      mxlc.cControls = 1;
      mxlc.cbmxctrl = sizeof(MIXERCONTROL);
      mxlc.pamxctrl = mxc;
      if(mixerGetLineControls((HMIXEROBJ)hmixer,&mxlc,MIXER_GETLINECONTROLSF_ONEBYTYPE))
         return 0;
      else
         return 1;
   }
   return 0;
}

//---------------------------------------------------------------------------
unsigned GetVolumeValue(HMIXER hmixer ,MIXERCONTROL *mxc)
{
   MIXERCONTROLDETAILS mxcd;
   MIXERCONTROLDETAILS_UNSIGNED vol; vol.dwValue=0;
   mxcd.hwndOwner = 0;
   mxcd.cbStruct = sizeof(mxcd);
   mxcd.dwControlID = mxc->dwControlID;
   mxcd.cbDetails = sizeof(vol);
   mxcd.paDetails = &vol;
   mxcd.cChannels = 1;
   if(mixerGetControlDetails((HMIXEROBJ)hmixer, &mxcd, MIXER_OBJECTF_HMIXER|MIXER_GETCONTROLDETAILSF_VALUE))
      return -1;
   return vol.dwValue;
}

//---------------------------------------------------------------------------

bool SetVolumeValue(HMIXER hmixer ,MIXERCONTROL *mxc, long volume)
{
   MIXERCONTROLDETAILS mxcd;
   MIXERCONTROLDETAILS_UNSIGNED vol;vol.dwValue = volume;
   mxcd.hwndOwner = 0;
   mxcd.dwControlID = mxc->dwControlID;
   mxcd.cbStruct = sizeof(mxcd);
   mxcd.cbDetails = sizeof(vol);
   mxcd.paDetails = &vol;
   mxcd.cChannels = 1;
   if(mixerSetControlDetails((HMIXEROBJ)hmixer, &mxcd, MIXER_OBJECTF_HMIXER|MIXER_SETCONTROLDETAILSF_VALUE))
      return 0;
   return 1;
}

//---------------------------------------------------------------------------
unsigned WINAPI GetVolume(int dev)//得到设备的音量dev=0主音量，1WAVE ,2MIDI ,3 LINE IN
{
   long device;
   unsigned rt=0;
   MIXERCONTROL volCtrl;
   HMIXER hmixer;
   switch (dev)
   {
   case 1: device=MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT; break;
   case 2: device=MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER; break;
   case 3:
     // device=MIXERLINE_COMPONENTTYPE_SRC_COMPACTDISC; break; // cd 音量
     device=MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE; break; //麦克风音量
     // device=MIXERLINE_COMPONENTTYPE_SRC_LINE; break; //PC 扬声器音量
     //device=MIXERLINE_COMPONENTTYPE_SRC_COMPACTDISC; break;
    default: device=MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;
   }

   if(mixerOpen(&hmixer, 0, 0, 0, 0)) return 0;
   if(!GetVolumeControl(hmixer,device,MIXERCONTROL_CONTROLTYPE_VOLUME,&volCtrl))
       return 0;
   rt=GetVolumeValue(hmixer,&volCtrl)*100/volCtrl.Bounds.lMaximum;
   mixerClose(hmixer);
   return rt;
}

//---------------------------------------------------------------------------

bool WINAPI SetVolume(long dev,long vol)//设置设备的音量
{
// dev =0,1,2 分别表示主音量,波形,MIDI ,LINE IN
// vol=0-100 表示音量的大小 , 设置与返回音量的值用的是百分比，即音量从0 - 100，而不是设备的绝对值
// retrun false 表示设置音量的大小的操作不成功
// retrun true 表示设置音量的大小的操作成功

   long device;
   bool rc=false;
   MIXERCONTROL volCtrl;
   HMIXER hmixer;
   switch (dev)
   {
      case 1: device=MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT; break;
      case 2: device=MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER; break;
      case 3: device=MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE; break; //麦克风音量
   default:device=MIXERLINE_COMPONENTTYPE_DST_SPEAKERS;
   }

   if(mixerOpen(&hmixer, 0, 0, 0, 0)) return 0;

   if(GetVolumeControl(hmixer,device,MIXERCONTROL_CONTROLTYPE_VOLUME,&volCtrl))
   {
      vol=vol*volCtrl.Bounds.lMaximum/100;
      if(SetVolumeValue(hmixer,&volCtrl,vol))
      rc=true;
   }
   mixerClose(hmixer);
   return rc;
}