Question

How can I change the master volume level? Using this code

[DllImport ('winmm.dll')] public static extern int waveOutSetVolume (IntPtr hwo, uint dwVolume);  waveOutSetVolume (IntPtr.Zero, (((uint)uint.MaxValue & 0x0000ffff) | ((uint)uint.MaxValue << 16))); 

I can set the wave volume but if the master volume is too low this won’t have any effect.

Thanks for any help.

Answer 1

Okay, here goes:

const int MAXPNAMELEN            = 32; const int MIXER_SHORT_NAME_CHARS = 16; const int MIXER_LONG_NAME_CHARS  = 64;  [Flags] enum MIXERLINE_LINEF : uint{     ACTIVE       = 0x00000001,     DISCONNECTED = 0x00008000,     SOURCE       = 0x80000000 } [Flags] enum MIXER           : uint{     GETLINEINFOF_DESTINATION     = 0x00000000,     GETLINEINFOF_SOURCE          = 0x00000001,     GETLINEINFOF_LINEID          = 0x00000002,     GETLINEINFOF_COMPONENTTYPE   = 0x00000003,     GETLINEINFOF_TARGETTYPE      = 0x00000004,     GETLINEINFOF_QUERYMASK       = 0x0000000F,      GETLINECONTROLSF_ALL         = 0x00000000,     GETLINECONTROLSF_ONEBYID     = 0x00000001,     GETLINECONTROLSF_ONEBYTYPE   = 0x00000002,     GETLINECONTROLSF_QUERYMASK   = 0x0000000F,      GETCONTROLDETAILSF_VALUE     = 0x00000000,     GETCONTROLDETAILSF_LISTTEXT  = 0x00000001,     GETCONTROLDETAILSF_QUERYMASK = 0x0000000F,      OBJECTF_MIXER                = 0x00000000,     OBJECTF_WAVEOUT              = 0x10000000,     OBJECTF_WAVEIN               = 0x20000000,     OBJECTF_MIDIOUT              = 0x30000000,     OBJECTF_MIDIIN               = 0x40000000,     OBJECTF_AUX                  = 0x50000000,     OBJECTF_HANDLE               = 0x80000000,     OBJECTF_HMIXER               = OBJECTF_HANDLE | OBJECTF_MIXER,     OBJECTF_HWAVEOUT             = OBJECTF_HANDLE | OBJECTF_WAVEOUT,     OBJECTF_HWAVEIN              = OBJECTF_HANDLE | OBJECTF_WAVEIN,     OBJECTF_HMIDIOUT             = OBJECTF_HANDLE | OBJECTF_MIDIOUT,     OBJECTF_HMIDIIN              = OBJECTF_HANDLE | OBJECTF_MIDIIN } [Flags] enum MIXERCONTROL_CT : uint{     CLASS_MASK        = 0xF0000000,     CLASS_CUSTOM      = 0x00000000,     CLASS_METER       = 0x10000000,     CLASS_SWITCH      = 0x20000000,     CLASS_NUMBER      = 0x30000000,     CLASS_SLIDER      = 0x40000000,     CLASS_FADER       = 0x50000000,     CLASS_TIME        = 0x60000000,     CLASS_LIST        = 0x70000000,      SUBCLASS_MASK     = 0x0F000000,      SC_SWITCH_BOOLEAN = 0x00000000,     SC_SWITCH_BUTTON  = 0x01000000,      SC_METER_POLLED   = 0x00000000,      SC_TIME_MICROSECS = 0x00000000,     SC_TIME_MILLISECS = 0x01000000,      SC_LIST_SINGLE    = 0x00000000,     SC_LIST_MULTIPLE  = 0x01000000,      UNITS_MASK        = 0x00FF0000,     UNITS_CUSTOM      = 0x00000000,     UNITS_BOOLEAN     = 0x00010000,     UNITS_SIGNED      = 0x00020000,     UNITS_UNSIGNED    = 0x00030000,     UNITS_DECIBELS    = 0x00040000, /* in 10ths */     UNITS_PERCENT     = 0x00050000, /* in 10ths */ } [Flags] enum MIXERCONTROL_CONTROLTYPE : uint{     CUSTOM         = MIXERCONTROL_CT.CLASS_CUSTOM | MIXERCONTROL_CT.UNITS_CUSTOM,     BOOLEANMETER   = MIXERCONTROL_CT.CLASS_METER | MIXERCONTROL_CT.SC_METER_POLLED | MIXERCONTROL_CT.UNITS_BOOLEAN,     SIGNEDMETER    = MIXERCONTROL_CT.CLASS_METER | MIXERCONTROL_CT.SC_METER_POLLED | MIXERCONTROL_CT.UNITS_SIGNED,     PEAKMETER      = SIGNEDMETER + 1,     UNSIGNEDMETER  = MIXERCONTROL_CT.CLASS_METER | MIXERCONTROL_CT.SC_METER_POLLED | MIXERCONTROL_CT.UNITS_UNSIGNED,     BOOLEAN        = MIXERCONTROL_CT.CLASS_SWITCH | MIXERCONTROL_CT.SC_SWITCH_BOOLEAN | MIXERCONTROL_CT.UNITS_BOOLEAN,     ONOFF          = BOOLEAN + 1,     MUTE           = BOOLEAN + 2,     MONO           = BOOLEAN + 3,     LOUDNESS       = BOOLEAN + 4,     STEREOENH      = BOOLEAN + 5,     BASS_BOOST     = BOOLEAN + 0x00002277,     BUTTON         = MIXERCONTROL_CT.CLASS_SWITCH | MIXERCONTROL_CT.SC_SWITCH_BUTTON | MIXERCONTROL_CT.UNITS_BOOLEAN,     DECIBELS       = MIXERCONTROL_CT.CLASS_NUMBER | MIXERCONTROL_CT.UNITS_DECIBELS,     SIGNED         = MIXERCONTROL_CT.CLASS_NUMBER | MIXERCONTROL_CT.UNITS_SIGNED,     UNSIGNED       = MIXERCONTROL_CT.CLASS_NUMBER | MIXERCONTROL_CT.UNITS_UNSIGNED,     PERCENT        = MIXERCONTROL_CT.CLASS_NUMBER | MIXERCONTROL_CT.UNITS_PERCENT,     SLIDER         = MIXERCONTROL_CT.CLASS_SLIDER | MIXERCONTROL_CT.UNITS_SIGNED,     PAN            = SLIDER + 1,     QSOUNDPAN      = SLIDER + 2,     FADER          = MIXERCONTROL_CT.CLASS_FADER | MIXERCONTROL_CT.UNITS_UNSIGNED,     VOLUME         = FADER + 1,     BASS           = FADER + 2,     TREBLE         = FADER + 3,     EQUALIZER      = FADER + 4,     SINGLESELECT   = MIXERCONTROL_CT.CLASS_LIST | MIXERCONTROL_CT.SC_LIST_SINGLE | MIXERCONTROL_CT.UNITS_BOOLEAN,     MUX            = SINGLESELECT + 1,     MULTIPLESELECT = MIXERCONTROL_CT.CLASS_LIST | MIXERCONTROL_CT.SC_LIST_MULTIPLE | MIXERCONTROL_CT.UNITS_BOOLEAN,     MIXER          = MULTIPLESELECT + 1,     MICROTIME      = MIXERCONTROL_CT.CLASS_TIME | MIXERCONTROL_CT.SC_TIME_MICROSECS | MIXERCONTROL_CT.UNITS_UNSIGNED,     MILLITIME      = MIXERCONTROL_CT.CLASS_TIME | MIXERCONTROL_CT.SC_TIME_MILLISECS | MIXERCONTROL_CT.UNITS_UNSIGNED }  [StructLayout(LayoutKind.Sequential, CharSet=CharSet.Auto)] struct MIXERLINE{     [StructLayout(LayoutKind.Sequential, CharSet=CharSet.Auto)]     public struct TargetInfo{         public uint   dwType;         public uint   dwDeviceID;         public ushort wMid;         public ushort wPid;         public uint   vDriverVersion;         [MarshalAs(UnmanagedType.ByValTStr, SizeConst=MAXPNAMELEN)]         public string szPname;     }      public uint            cbStruct;     public uint            dwDestination;     public uint            dwSource;     public uint            dwLineID;     public MIXERLINE_LINEF fdwLine;     public uint            dwUser;     public uint            dwComponentType;     public uint            cChannels;     public uint            cConnection;     public uint            cControls;     [MarshalAs(UnmanagedType.ByValTStr, SizeConst=MIXER_SHORT_NAME_CHARS)]     public string          szShortName;     [MarshalAs(UnmanagedType.ByValTStr, SizeConst=MIXER_LONG_NAME_CHARS)]     public string          szName;     public TargetInfo      Target; } [StructLayout(LayoutKind.Sequential, CharSet=CharSet.Auto)] struct MIXERCONTROL{     [StructLayout(LayoutKind.Explicit)]     public struct BoundsInfo{         [FieldOffset(0)]         public int    lMinimum;         [FieldOffset(4)]         public int    lMaximum;         [FieldOffset(0)]         public uint   dwMinimum;         [FieldOffset(4)]         public uint   dwMaximum;         [FieldOffset(8), MarshalAs(UnmanagedType.ByValArray, SizeConst=4)]         public uint[] dwReserved;     }     [StructLayout(LayoutKind.Explicit)]     public struct MetricsInfo{         [FieldOffset(0)]         public uint   cSteps;         [FieldOffset(0)]         public uint   cbCustomData;         [FieldOffset(4), MarshalAs(UnmanagedType.ByValArray, SizeConst=5)]         public uint[] dwReserved;     }      public uint                     cbStruct;     public uint                     dwControlID;     public MIXERCONTROL_CONTROLTYPE dwControlType;     public uint                     fdwControl;     public uint                     cMultipleItems;     [MarshalAs(UnmanagedType.ByValTStr, SizeConst=MIXER_SHORT_NAME_CHARS)]     public string                   szShortName;     [MarshalAs(UnmanagedType.ByValTStr, SizeConst=MIXER_LONG_NAME_CHARS)]     public string                   szName;     public BoundsInfo               Bounds;     public MetricsInfo              Metrics; } [StructLayout(LayoutKind.Explicit)] struct MIXERLINECONTROLS{     [FieldOffset(0)]     public uint   cbStruct;     [FieldOffset(4)]     public uint   dwLineID;     [FieldOffset(8)]     public uint   dwControlID;     [FieldOffset(8)] // not a typo!  overlaps previous field     public uint   dwControlType;     [FieldOffset(12)]     public uint   cControls;     [FieldOffset(16)]     public uint   cbmxctrl;     [FieldOffset(20)]     public IntPtr pamxctrl; } [StructLayout(LayoutKind.Explicit)] struct MIXERCONTROLDETAILS{     [FieldOffset(0)]     public uint   cbStruct;     [FieldOffset(4)]     public uint   dwControlID;     [FieldOffset(8)]     public uint   cChannels;     [FieldOffset(12)]     public IntPtr hwndOwner;     [FieldOffset(12)] // not a typo!     public uint   cMultipleItems;     [FieldOffset(16)]     public uint   cbDetails;     [FieldOffset(20)]     public IntPtr paDetails; } [StructLayout(LayoutKind.Sequential)] struct VOLUME{     public int left;     public int right; } struct MixerInfo{     public uint volumeCtl;     public uint muteCtl;     public int  minVolume;     public int  maxVolume; }  [DllImport('WinMM.dll', CharSet=CharSet.Auto)] static extern uint mixerGetLineInfo      (IntPtr hmxobj, ref MIXERLINE pmxl, MIXER flags);  [DllImport('WinMM.dll', CharSet=CharSet.Auto)] static extern uint mixerGetLineControls  (IntPtr hmxobj, ref MIXERLINECONTROLS pmxlc, MIXER flags);  [DllImport('WinMM.dll', CharSet=CharSet.Auto)] static extern uint mixerGetControlDetails(IntPtr hmxobj, ref MIXERCONTROLDETAILS pmxcd, MIXER flags);  [DllImport('WinMM.dll', CharSet=CharSet.Auto)] static extern uint mixerSetControlDetails(IntPtr hmxobj, ref MIXERCONTROLDETAILS pmxcd, MIXER flags);  static MixerInfo GetMixerControls(){     MIXERLINE         mxl = new MIXERLINE();     MIXERLINECONTROLS mlc = new MIXERLINECONTROLS();     mxl.cbStruct = (uint)Marshal.SizeOf(typeof(MIXERLINE));     mlc.cbStruct = (uint)Marshal.SizeOf(typeof(MIXERLINECONTROLS));      mixerGetLineInfo(IntPtr.Zero, ref mxl, MIXER.OBJECTF_MIXER | MIXER.GETLINEINFOF_DESTINATION);      mlc.dwLineID  = mxl.dwLineID;     mlc.cControls = mxl.cControls;     mlc.cbmxctrl  = (uint)Marshal.SizeOf(typeof(MIXERCONTROL));     mlc.pamxctrl  = Marshal.AllocHGlobal((int)(mlc.cbmxctrl * mlc.cControls));      mixerGetLineControls(IntPtr.Zero, ref mlc, MIXER.OBJECTF_MIXER | MIXER.GETLINECONTROLSF_ALL);      MixerInfo rtn = new MixerInfo();      for(int i = 0; i < mlc.cControls; i++){         MIXERCONTROL mxc = (MIXERCONTROL)Marshal.PtrToStructure((IntPtr)((int)mlc.pamxctrl + (int)mlc.cbmxctrl * i), typeof(MIXERCONTROL));         switch(mxc.dwControlType){         case MIXERCONTROL_CONTROLTYPE.VOLUME:             rtn.volumeCtl = mxc.dwControlID;             rtn.minVolume = mxc.Bounds.lMinimum;             rtn.maxVolume = mxc.Bounds.lMaximum;             break;         case MIXERCONTROL_CONTROLTYPE.MUTE:             rtn.muteCtl = mxc.dwControlID;             break;         }     }      Marshal.FreeHGlobal(mlc.pamxctrl);      return rtn; } static VOLUME GetVolume(MixerInfo mi){     MIXERCONTROLDETAILS mcd = new MIXERCONTROLDETAILS();     mcd.cbStruct       = (uint)Marshal.SizeOf(typeof(MIXERCONTROLDETAILS));     mcd.dwControlID    = mi.volumeCtl;     mcd.cMultipleItems = 0;     mcd.cChannels      = 2;     mcd.cbDetails      = (uint)Marshal.SizeOf(typeof(int));     mcd.paDetails      = Marshal.AllocHGlobal((int)mcd.cbDetails);      mixerGetControlDetails(IntPtr.Zero, ref mcd, MIXER.GETCONTROLDETAILSF_VALUE | MIXER.OBJECTF_MIXER);      VOLUME rtn = (VOLUME)Marshal.PtrToStructure(mcd.paDetails, typeof(VOLUME));      Marshal.FreeHGlobal(mcd.paDetails);      return rtn; } static bool IsMuted(MixerInfo mi){     MIXERCONTROLDETAILS mcd = new MIXERCONTROLDETAILS();     mcd.cbStruct       = (uint)Marshal.SizeOf(typeof(MIXERCONTROLDETAILS));     mcd.dwControlID    = mi.muteCtl;     mcd.cMultipleItems = 0;     mcd.cChannels      = 1;     mcd.cbDetails      = 4;     mcd.paDetails      = Marshal.AllocHGlobal((int)mcd.cbDetails);      mixerGetControlDetails(IntPtr.Zero, ref mcd, MIXER.GETCONTROLDETAILSF_VALUE | MIXER.OBJECTF_MIXER);      int rtn = Marshal.ReadInt32(mcd.paDetails);      Marshal.FreeHGlobal(mcd.paDetails);      return rtn != 0; } static void AdjustVolume(MixerInfo mi, int delta){     VOLUME volume = GetVolume(mi);      if(delta > 0){         volume.left  = Math.Min(mi.maxVolume, volume.left  + delta);         volume.right = Math.Min(mi.maxVolume, volume.right + delta);     }else{         volume.left  = Math.Max(mi.minVolume, volume.left  + delta);         volume.right = Math.Max(mi.minVolume, volume.right + delta);     }      SetVolume(mi, volume); } static void SetVolume(MixerInfo mi, VOLUME volume){     MIXERCONTROLDETAILS mcd = new MIXERCONTROLDETAILS();     mcd.cbStruct       = (uint)Marshal.SizeOf(typeof(MIXERCONTROLDETAILS));     mcd.dwControlID    = mi.volumeCtl;     mcd.cMultipleItems = 0;     mcd.cChannels      = 2;     mcd.cbDetails      = (uint)Marshal.SizeOf(typeof(int));     mcd.paDetails      = Marshal.AllocHGlobal((int)mcd.cbDetails);      Marshal.StructureToPtr(volume, mcd.paDetails, false);      mixerSetControlDetails(IntPtr.Zero, ref mcd, MIXER.GETCONTROLDETAILSF_VALUE | MIXER.OBJECTF_MIXER);      Marshal.FreeHGlobal(mcd.paDetails); } static void SetMute(MixerInfo mi, bool mute){     MIXERCONTROLDETAILS mcd = new MIXERCONTROLDETAILS();     mcd.cbStruct       = (uint)Marshal.SizeOf(typeof(MIXERCONTROLDETAILS));     mcd.dwControlID    = mi.muteCtl;     mcd.cMultipleItems = 0;     mcd.cChannels      = 1;     mcd.cbDetails      = 4;     mcd.paDetails      = Marshal.AllocHGlobal((int)mcd.cbDetails);      Marshal.WriteInt32(mcd.paDetails, mute ? 1 : 0);      mixerSetControlDetails(IntPtr.Zero, ref mcd, MIXER.GETCONTROLDETAILSF_VALUE | MIXER.OBJECTF_MIXER);      Marshal.FreeHGlobal(mcd.paDetails); } 

This code is huge and ugly. It’s a translation of some C++ code, and with having to define all the P/Invoke stuff, it’s a lot more code. But I’ve tested it, and it works. To use it, you simply need something like:

MixerInfo mi = GetMixerControls(); AdjustVolume(mi, 100);    // add 100 to the current volume 

or

MixerInfo mi = GetMixerControls(); AdjustVolume(mi, (mi.maxVolume - mi.minVolume) / 10);    // increase the volume by 10% of total range 

or

MixerInfo mi = GetMixerControls(); SetVolume(mi, mi.maxVolume);    // let's get this party crunk'd! 

or

MixerInfo mi = GetMixerControls(); SetMute(mi, true);    // shhhh!!!!!! 

WARNING

Due to the use of fixed-sized ints and field offsets, this may fail fantastically on 64-bit Windows. I don’t know, I haven’t tested it and haven’t paid enough attention to know if these field sizes expand to 64 bits. caveat codor

EDIT

For the sake of simplicity (relatively speaking), I’ve left out any error handling. You should really check the return codes of all the mixerXXX functions, but I’ll leave that as an exercise for the reader (read as: I was too lazy to do this).