噪音及mixer

来源：互联网发布：2016最新网络语言编辑：程序博客网时间：2024/04/27 19:30

3524关于AC97声卡选择stereo mix录制的致命问题：
如果客户端有声音传送到服务端（不论是通过什么方式，可以是stereo mix录制过来的，也可以是
microphone录制过来的，或通过其它方式录制传送过来的），将导致服务端将客户端传送过来的
声音也进行录制，然后在传送给客户端，因此导致声音变成噪音。

而有的HD声卡，因为所有录制（stereo microphone line in等）默认都是开启的，也会有相关问题。
因为在默认情况下，所有录制都是开启状态，如果PC连接有line in线，且line in线有声音传送到PC，
而microphone也有声音输入，那么PC将分别通过line in录制和microphone录制将声音传送到远端，
同时，stereo也会将录制到的声音传送到远端，产生噪音。在这种情况下，应该关闭某些录制选项。

AC97客户端stereo --------- AC97服务端stereo ERROR

AC97客户端stereo --------- AC97服务端Line in ？？？

这个应该没有问题！！

AC97客户端stereo --------- HD服务端不选择（本想选stereo）？？？

这个应该会有和下面一样的问题~~

AC97客户端stereo --------- HD服务端不选择（本想选Line） ERROR

这种情况下，如果将AC97客户端改为mic，将没有问题，可以接收到声音。说明服务端采用了Line in
录制，没有采用stereo录制，虽然两个都是开启状态。但如果AC97客户端选择stereo，将出现噪音，
说明服务端采用了Line in录制和stereo录制，或者只采用了stereo录制，这是怎么回事呢？

HD客户端不选择 --------- AC97服务端stereo

这种情况下，skype应该会选择microphone！！！所以出现噪音的可能性不大！！！

HD客户端不选择 --------- AC97服务端Line IN OK

混音器设备（USB EMP Audio Device）静音控制
void SetDeviceMute(BOOL bValue)
{
MMRESULT mmResult;
HMIXER hMixer;
MIXERCAPS mixercaps;

MIXERLINE mixerline;
memset(&mixerline,0,sizeof(MIXERLINE));
mixerline.cbStruct = sizeof(MIXERLINE);

MIXERLINECONTROLS mlc;
memset(&mlc,0,sizeof(MIXERLINECONTROLS));
mlc.cbStruct = sizeof(MIXERLINECONTROLS);

MIXERCONTROL mc;
memset(&mc,0,sizeof(MIXERCONTROL));
mc.cbStruct = sizeof(MIXERCONTROL);

UINT uNum = mixerGetNumDevs();
for ( int i = 0; i < uNum; i++ )
{
  mmResult = mixerOpen(&hMixer,i,0,0,MIXER_OBJECTF_MIXER);
  mmResult = mixerGetDevCaps(i,&mixercaps,sizeof(MIXERCAPS));
  for ( int j = 0; j < mixercaps.cDestinations; j++ )
  {
   mixerline.dwDestination = j;
   mmResult = mixerGetLineInfo((HMIXEROBJ)hMixer,&mixerline,MIXER_GETLINEINFOF_DESTINATION);
   if ( mixerline.dwComponentType == MIXERLINE_COMPONENTTYPE_DST_WAVEIN && mixercaps.cDestinations == 1)
   {
    mlc.cControls = 1;
    mlc.cbmxctrl = sizeof(MIXERCONTROL);
    mlc.pamxctrl = &mc;
    mlc.dwLineID = mixerline.dwLineID;
    mlc.dwControlType = MIXERCONTROL_CONTROLTYPE_MUTE;
    mmResult = mixerGetLineControls((HMIXEROBJ)hMixer,&mlc,MIXER_OBJECTF_HMIXER | MIXER_GETLINECONTROLSF_ONEBYTYPE);

MIXERCONTROLDETAILS_BOOLEAN *pmxcdMute = (MIXERCONTROLDETAILS_BOOLEAN*)malloc(sizeof(MIXERCONTROLDETAILS_BOOLEAN));

pmxcdMute[0].fValue = bValue;

MIXERCONTROLDETAILS mixercontroldetails;
memset(&mixercontroldetails,0,sizeof(MIXERCONTROLDETAILS));

mmResult = mixerSetControlDetails((HMIXEROBJ)hMixer,&mixercontroldetails,MIXER_SETCONTROLDETAILSF_VALUE | MIXER_OBJECTF_HMIXER);
free(pmxcdMute);

}
}
}
mixerClose(hMixer);
}

Audio Mixer Device音量调节

void AdjustDeviceVolume(BOOL bVolumeUp)
{
MMRESULT mmResult;
HMIXER hMixer;
MIXERCAPS mixercaps;

MIXERLINE mixerline;
memset(&mixerline,0,sizeof(MIXERLINE));
mixerline.cbStruct = sizeof(MIXERLINE);

MIXERLINECONTROLS mlc;
memset(&mlc,0,sizeof(MIXERLINECONTROLS));
mlc.cbStruct = sizeof(MIXERLINECONTROLS);

MIXERCONTROL mc;
memset(&mc,0,sizeof(MIXERCONTROL));
mc.cbStruct = sizeof(MIXERCONTROL);

UINT uNum = mixerGetNumDevs();
for ( int i = 0; i < uNum; i++ )
{
  mmResult = mixerOpen(&hMixer,i,0,0,MIXER_OBJECTF_MIXER);
  mmResult = mixerGetDevCaps(i,&mixercaps,sizeof(MIXERCAPS));
  for ( int j = 0; j < mixercaps.cDestinations; j++ )
  {
   mixerline.dwDestination = j;
   mmResult = mixerGetLineInfo((HMIXEROBJ)hMixer,&mixerline,MIXER_GETLINEINFOF_DESTINATION);
   if ( mixerline.dwComponentType == MIXERLINE_COMPONENTTYPE_DST_WAVEIN && mixercaps.cDestinations == 1)
   {
    mlc.cControls = 1;
    mlc.cbmxctrl = sizeof(MIXERCONTROL);
    mlc.pamxctrl = &mc;
    mlc.dwLineID = mixerline.dwLineID;
    mlc.dwControlType = MIXERCONTROL_CONTROLTYPE_VOLUME;
    mmResult = mixerGetLineControls((HMIXEROBJ)hMixer,&mlc,MIXER_OBJECTF_HMIXER | MIXER_GETLINECONTROLSF_ONEBYTYPE);

    MIXERCONTROLDETAILS_BOOLEAN* pControlDetail_BOOL = (MIXERCONTROLDETAILS_BOOLEAN*)malloc(mixerline.cChannels*sizeof(MIXERCONTROLDETAILS_BOOLEAN));
    if ( !pControlDetail_BOOL )
     return;

MIXERCONTROLDETAILS mixercontroldetails;
memset(&mixercontroldetails,0,sizeof(MIXERCONTROLDETAILS));

    mixercontroldetails.cbStruct = sizeof(MIXERCONTROLDETAILS);
    mixercontroldetails.cbDetails = sizeof(MIXERCONTROLDETAILS_BOOLEAN);
    mixercontroldetails.cChannels = 1;
    mixercontroldetails.cMultipleItems = 0;
    mixercontroldetails.paDetails = &pControlDetail_BOOL[0];
    mixercontroldetails.dwControlID = mc.dwControlID;

mmResult = mixerGetControlDetails((HMIXEROBJ)hMixer,&mixercontroldetails,MIXER_GETCONTROLDETAILSF_VALUE | MIXER_OBJECTF_HMIXER);

    for ( int i = 0; i < mixerline.cChannels; i++ )
    {
     if(bVolumeUp)
     {
      pControlDetail_BOOL[i].fValue += 13107;
      if( pControlDetail_BOOL[i].fValue > 65535 )
      {
       pControlDetail_BOOL[i].fValue = 65535;
      }
     }
     else
     {
      pControlDetail_BOOL[i].fValue -= 13107;
      if( pControlDetail_BOOL[i].fValue < 0 )
      {
       pControlDetail_BOOL[i].fValue = 0;
      }
     }
    }

mmResult = mixerSetControlDetails((HMIXEROBJ)hMixer,&mixercontroldetails,MIXER_SETCONTROLDETAILSF_VALUE | MIXER_OBJECTF_HMIXER);

free(pControlDetail_BOOL);

}
}
}
mixerClose(hMixer);
}

void MuteMasterAudio()
{
MMRESULT mmResult;
HMIXER hMixer;
MIXERCAPS mixercaps;

MIXERLINE mixerline;
memset(&mixerline,0,sizeof(MIXERLINE));
mixerline.cbStruct = sizeof(MIXERLINE);

MIXERLINECONTROLS mlc;
memset(&mlc,0,sizeof(MIXERLINECONTROLS));
mlc.cbStruct = sizeof(MIXERLINECONTROLS);

MIXERCONTROL mc;
memset(&mc,0,sizeof(MIXERCONTROL));
mc.cbStruct = sizeof(MIXERCONTROL);

DWORD dwStereoSelControlID;

UINT uNum = mixerGetNumDevs();
for ( int i = 0; i < uNum; i++ )
{
  mmResult = mixerOpen(&hMixer,i,0,0,MIXER_OBJECTF_MIXER);
  mmResult = mixerGetDevCaps(i,&mixercaps,sizeof(MIXERCAPS));
  for ( int j = 0; j < mixercaps.cDestinations; j++ )
  {
   mixerline.dwDestination = j;
   mmResult = mixerGetLineInfo((HMIXEROBJ)hMixer,&mixerline,MIXER_GETLINEINFOF_DESTINATION);
   if ( mixerline.dwComponentType == MIXERLINE_COMPONENTTYPE_DST_SPEAKERS )
   {
    mlc.cControls = 1;
    mlc.cbmxctrl = sizeof(MIXERCONTROL);
    mlc.pamxctrl = &mc;
    mlc.dwLineID = mixerline.dwLineID;
    mlc.dwControlType = MIXERCONTROL_CONTROLTYPE_MUTE;
    mmResult = mixerGetLineControls((HMIXEROBJ)hMixer,&mlc,MIXER_OBJECTF_HMIXER | MIXER_GETLINECONTROLSF_ONEBYTYPE);

dwStereoSelControlID = mc.dwControlID;

    MIXERCONTROLDETAILS_BOOLEAN *pmxcdMute = (MIXERCONTROLDETAILS_BOOLEAN*)malloc(sizeof(MIXERCONTROLDETAILS_BOOLEAN));

    pmxcdMute[0].fValue = TRUE;

    MIXERCONTROLDETAILS mixercontroldetails;
    memset(&mixercontroldetails,0,sizeof(MIXERCONTROLDETAILS));

    mixercontroldetails.cbStruct = sizeof(MIXERCONTROLDETAILS);
    mixercontroldetails.cbDetails = sizeof(MIXERCONTROLDETAILS_BOOLEAN);
    mixercontroldetails.cChannels = 1;
    mixercontroldetails.paDetails = pmxcdMute;
    mixercontroldetails.dwControlID = dwStereoSelControlID;

    mmResult = mixerSetControlDetails((HMIXEROBJ)hMixer,&mixercontroldetails,MIXER_SETCONTROLDETAILSF_VALUE | MIXER_OBJECTF_HMIXER);
    free(pmxcdMute);

    }
   }
  }
  mixerClose(hMixer);
}