[RESOLVED] How to change master volume level?

[HongKongCV]

Okay, I have an application that plays wav and mp3 files using the Microsoft.DirectX.AudioVideoPlayback.Audio() function. It works fine, and I can easily set the volume level of the playback... within limits.

That limit is the system volume level. I can set the playback level for the mp3, but if the system volume is muted or set real low it may still play softly. So I want to add controls that will tell the user what the system volume and mute are set to, and allow him to change those from inside my app.

So how do I set the master volume level, including making sure it isn't muted?

[sapator]

Hi.
So here is a mixture of random classes i've found over the net.Most of them in VB6 so i had a heck of a time changing them.
What works is the ''mixersetter.SetVolume (zero for no sound)
and the mixsetter.Getvolume.
Muting and finding if a control is muted proved very complex.If anyone from the API people here can take a look.Basically the problem is that the MIXERCONTROLDETAILS is not getting the dwControlID.

So i will post the class (mixersetter), you must import it on your appliaction and the do a mixersetter.SetVolume(0) to low the volume. If you provide larger numbers then the volume will raise.

Mind you it very big so i will probably cut it in 2-3 posts.

Imports System
Imports System.Runtime.InteropServices
Public Class mixersetter
    Public Const MMSYSERR_NOERROR As Integer = 0
    Public Const MAXPNAMELEN As Integer = 32
    Public Const MIXER_LONG_NAME_CHARS As Integer = 64
    Public Const MIXER_SHORT_NAME_CHARS As Integer = 16
    Public Const MIXER_GETLINEINFOF_COMPONENTTYPE As Integer = &H3
    Public Const MIXER_GETCONTROLDETAILSF_VALUE As Integer = &H0
    Public Const MIXER_GETLINECONTROLSF_ONEBYTYPE As Integer = &H2
    Public Const MIXER_SETCONTROLDETAILSF_VALUE As Integer = &H0
    Public Const MIXERLINE_COMPONENTTYPE_DST_FIRST As Integer = &H0
    Public Const MIXERLINE_COMPONENTTYPE_SRC_FIRST As Integer = &H1000
    Public Const MIXERLINE_COMPONENTTYPE_DST_SPEAKERS As Integer = (MIXERLINE_COMPONENTTYPE_DST_FIRST + 4)
    Public Const MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE As Integer = (MIXERLINE_COMPONENTTYPE_SRC_FIRST + 3)
    Public Const MIXERLINE_COMPONENTTYPE_SRC_LINE As Integer = (MIXERLINE_COMPONENTTYPE_SRC_FIRST + 2)
    Public Const MIXERCONTROL_CT_CLASS_FADER As Integer = &H50000000
    Public Const MIXERCONTROL_CT_UNITS_UNSIGNED As Integer = &H30000
    Public Const MIXERCONTROL_CONTROLTYPE_FADER As Integer = (MIXERCONTROL_CT_CLASS_FADER Or MIXERCONTROL_CT_UNITS_UNSIGNED)
    Public Const MIXERCONTROL_CONTROLTYPE_VOLUME As Integer = (MIXERCONTROL_CONTROLTYPE_FADER + 1)

    Private Declare Function mixerGetLineInfo Lib "winmm.dll" Alias "mixerGetLineInfoA" (ByVal hmxobj As Int32, ByVal pmxl As MIXERLINE, ByVal fdwInfo As Int32) As Int32


    Private Declare Function GlobalAlloc Lib "kernel32" (ByVal wFlags As Int32, ByVal dwBytes As Int32) As Int32
    Private Declare Function GlobalLock Lib "kernel32" (ByVal hMem As Int32) As IntPtr
    Private Declare Function GlobalFree Lib "kernel32" (ByVal hMem As Int32) As Int32
    Private Declare Function mixerGetLineControls Lib "winmm.dll" Alias "mixerGetLineControlsA" (ByVal hmxobj As Int32, ByVal pmxlc As MIXERLINECONTROLS, ByVal fdwControls As Int32) As Int32
    Public Shared uMixerControls(20) As MIXERCONTROL ' local array to store mixer controls

    Public Shared hMixerHandle As Int32                    ' handle for mixer

    ''Private Declare Sub CopyStructFromPtr Lib "kernel32" Alias "RtlMoveMemory" (ByVal struct As Object, ByVal ptr As IntPtr, ByVal cb As Int32)
    Private Declare Sub CopyStructFromPtr Lib "kernel32" Alias "RtlMoveMemory" (<MarshalAs(UnmanagedType.AsAny)> ByVal struct As Object, ByVal ptr As IntPtr, ByVal cb As Int32)
    '' Private Declare Sub CopyPtrFromStruct Lib "kernel32" Alias "RtlMoveMemory" (ByVal ptr As IntPtr, ByVal struct As Object, ByVal cb As Int32)
    Private Declare Sub CopyPtrFromStruct Lib "kernel32" Alias "RtlMoveMemory" (ByVal ptr As IntPtr, <MarshalAs(UnmanagedType.AsAny)> ByVal struct As Object, ByVal cb As Int32)




    '
    '   MMRESULT error return values specific to the mixer API
    '
    Private Const MIXERR_BASE = 1024
    Private Const MIXERR_INVALLINE = (MIXERR_BASE + 0)
    Private Const MIXERR_INVALCONTROL = (MIXERR_BASE + 1)
    Private Const MIXERR_INVALVALUE = (MIXERR_BASE + 2)
    Private Const MIXERR_LASTERROR = (MIXERR_BASE + 2)

    Private Const MIXER_OBJECTF_HANDLE = &H80000000
    Private Const MIXER_OBJECTF_MIXER = &H0&

    Private Const MIXER_OBJECTF_HMIXER = (MIXER_OBJECTF_HANDLE Or MIXER_OBJECTF_MIXER)

    Private Const MIXER_OBJECTF_WAVEOUT = &H10000000

    Private Const MIXER_OBJECTF_HWAVEOUT = (MIXER_OBJECTF_HANDLE Or MIXER_OBJECTF_WAVEOUT)

    Private Const MIXER_OBJECTF_WAVEIN = &H20000000

    Private Const MIXER_OBJECTF_HWAVEIN = (MIXER_OBJECTF_HANDLE Or MIXER_OBJECTF_WAVEIN)

    Private Const MIXER_OBJECTF_MIDIOUT = &H30000000

    Private Const MIXER_OBJECTF_HMIDIOUT = (MIXER_OBJECTF_HANDLE Or MIXER_OBJECTF_MIDIOUT)

    Private Const MIXER_OBJECTF_MIDIIN = &H40000000

    Private Const MIXER_OBJECTF_HMIDIIN = (MIXER_OBJECTF_HANDLE Or MIXER_OBJECTF_MIDIIN)

    Private Const MIXER_OBJECTF_AUX = &H50000000
    '
    '   MIXERLINE.fdwLine
    '
    Private Const MIXERLINE_LINEF_ACTIVE = &H1&
    Private Const MIXERLINE_LINEF_DISCONNECTED = &H8000&
    Private Const MIXERLINE_LINEF_SOURCE = &H80000000
    '
    '   MIXERLINE.dwComponentType
    '


    Private Const MIXERLINE_COMPONENTTYPE_DST_UNDEFINED = (MIXERLINE_COMPONENTTYPE_DST_FIRST + 0)
    Private Const MIXERLINE_COMPONENTTYPE_DST_DIGITAL = (MIXERLINE_COMPONENTTYPE_DST_FIRST + 1)
    Private Const MIXERLINE_COMPONENTTYPE_DST_LINE = (MIXERLINE_COMPONENTTYPE_DST_FIRST + 2)
    Private Const MIXERLINE_COMPONENTTYPE_DST_MONITOR = (MIXERLINE_COMPONENTTYPE_DST_FIRST + 3)

    Private Const MIXERLINE_COMPONENTTYPE_DST_HEADPHONES = (MIXERLINE_COMPONENTTYPE_DST_FIRST + 5)
    Private Const MIXERLINE_COMPONENTTYPE_DST_TELEPHONE = (MIXERLINE_COMPONENTTYPE_DST_FIRST + 6)
    Private Const MIXERLINE_COMPONENTTYPE_DST_WAVEIN = (MIXERLINE_COMPONENTTYPE_DST_FIRST + 7)




    Private Const MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER = (MIXERLINE_COMPONENTTYPE_SRC_FIRST + 4)
    Private Const MIXERLINE_COMPONENTTYPE_SRC_COMPACTDISC = (MIXERLINE_COMPONENTTYPE_SRC_FIRST + 5)
    Private Const MIXERLINE_COMPONENTTYPE_SRC_PCSPEAKER = (MIXERLINE_COMPONENTTYPE_SRC_FIRST + 7)
    Private Const MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT = (MIXERLINE_COMPONENTTYPE_SRC_FIRST + 8)
    Private Const MIXERLINE_COMPONENTTYPE_SRC_AUXILIARY = (MIXERLINE_COMPONENTTYPE_SRC_FIRST + 9)

    '
    '   MIXERLINE.Target.dwType
    '
    Private Const MIXERLINE_TARGETTYPE_UNDEFINED = 0
    Private Const MIXERLINE_TARGETTYPE_WAVEOUT = 1
    Private Const MIXERLINE_TARGETTYPE_WAVEIN = 2
    Private Const MIXERLINE_TARGETTYPE_MIDIOUT = 3
    Private Const MIXERLINE_TARGETTYPE_MIDIIN = 4
    Private Const MIXERLINE_TARGETTYPE_AUX = 5


    '
    '   MIXERCONTROL.fdwControl
    '
    Private Const MIXERCONTROL_CONTROLF_UNIFORM = &H1&
    Private Const MIXERCONTROL_CONTROLF_MULTIPLE = &H2&
    Private Const MIXERCONTROL_CONTROLF_DISABLED = &H80000000
    '
    '   MIXERCONTROL_CONTROLTYPE_xxx building block defines
    '
    Private Const MIXERCONTROL_CT_CLASS_SWITCH = &H20000000

    Private Const MIXERCONTROL_CT_SC_SWITCH_BOOLEAN = &H0&
    Private Const MIXERCONTROL_CT_UNITS_BOOLEAN = &H10000






    Private Const MIXERCONTROL_CONTROLTYPE_BOOLEAN = (MIXERCONTROL_CT_CLASS_SWITCH Or MIXERCONTROL_CT_SC_SWITCH_BOOLEAN Or MIXERCONTROL_CT_UNITS_BOOLEAN)
    Private Const MIXERCONTROL_CONTROLTYPE_MUTE = (MIXERCONTROL_CONTROLTYPE_BOOLEAN + 2)

[sapator]

    <DllImport("winmm.dll", CharSet:=CharSet.Ansi)> _
Private Shared Function mixerClose(ByVal hmx As Integer) As Integer
    End Function
    <DllImport("winmm.dll", CharSet:=CharSet.Ansi)> _
    Private Shared Function mixerGetControlDetailsA(ByVal hmxobj As Integer, ByRef pmxcd As MIXERCONTROLDETAILS, ByVal fdwDetails As Integer) As Integer
    End Function
    <DllImport("winmm.dll", CharSet:=CharSet.Ansi)> _
    Private Shared Function mixerGetDevCapsA(ByVal uMxId As Integer, ByVal pmxcaps As MIXERCAPS, ByVal cbmxcaps As Integer) As Integer
    End Function
    <DllImport("winmm.dll", CharSet:=CharSet.Ansi)> _
    Private Shared Function mixerGetID(ByVal hmxobj As Integer, ByVal pumxID As Integer, ByVal fdwId As Integer) As Integer
    End Function
    <DllImport("winmm.dll", CharSet:=CharSet.Ansi)> _
    Private Shared Function mixerGetLineControlsA(ByVal hmxobj As Integer, ByRef pmxlc As MIXERLINECONTROLS, ByVal fdwControls As Integer) As Integer
    End Function
    <DllImport("winmm.dll", CharSet:=CharSet.Ansi)> _
    Private Shared Function mixerGetLineInfoA(ByVal hmxobj As Integer, ByRef pmxl As MIXERLINE, ByVal fdwInfo As Integer) As Integer
    End Function
    <DllImport("winmm.dll", CharSet:=CharSet.Ansi)> _
    Private Shared Function mixerGetNumDevs() As Integer
    End Function
    <DllImport("winmm.dll", CharSet:=CharSet.Ansi)> _
    Private Shared Function mixerMessage(ByVal hmx As Integer, ByVal uMsg As Integer, ByVal dwParam1 As Integer, ByVal dwParam2 As Integer) As Integer
    End Function
    <DllImport("winmm.dll", CharSet:=CharSet.Ansi)> _
    Private Shared Function mixerOpen(ByRef phmx As Integer, ByVal uMxId As Integer, ByVal dwCallback As Integer, ByVal dwInstance As Integer, ByVal fdwOpen As Integer) As Integer
    End Function
    <DllImport("winmm.dll", CharSet:=CharSet.Ansi)> _
    Private Shared Function mixerSetControlDetails(ByVal hmxobj As Integer, ByRef pmxcd As MIXERCONTROLDETAILS, ByVal fdwDetails As Integer) As Integer
    End Function

    Public Structure MIXERCAPS
        Public wMid As Integer
        Public wPid As Integer
        Public vDriverVersion As Integer
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=MAXPNAMELEN)> _
        Public szPname As String
        Public fdwSupport As Integer
        Public cDestinations As Integer
    End Structure

    Public Structure MIXERCONTROL
        Public cbStruct As Integer
        Public dwControlID As Integer
        Public dwControlType As Integer
        Public fdwControl As Integer
        Public cMultipleItems As Integer
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=MIXER_SHORT_NAME_CHARS)> _
        Public szShortName As String
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=MIXER_LONG_NAME_CHARS)> _
        Public szName As String
        Public lMinimum As Integer
        Public lMaximum As Integer
        <MarshalAs(UnmanagedType.U4, SizeConst:=10)> _
        Public reserved As Integer
    End Structure


    Public Structure MIXERCONTROLDETAILS
        Public cbStruct As Integer
        Public dwControlID As Integer
        Public cChannels As Integer
        Public item As Integer
        Public cbDetails As Integer
        Public paDetails As IntPtr
    End Structure

    Public Structure MIXERCONTROLDETAILS_UNSIGNED
        Public dwValue As Integer
    End Structure

    Public Structure MIXERLINE
        Public cbStruct As Integer
        Public dwDestination As Integer
        Public dwSource As Integer
        Public dwLineID As Integer
        Public fdwLine As Integer
        Public dwUser As Integer
        Public dwComponentType As Integer
        Public cChannels As Integer
        Public cConnections As Integer
        Public cControls As Integer
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=MIXER_SHORT_NAME_CHARS)> _
        Public szShortName As String
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=MIXER_LONG_NAME_CHARS)> _
        Public szName As String
        Public dwType As Integer
        Public dwDeviceID As Integer
        Public wMid As Integer
        Public wPid As Integer
        Public vDriverVersion As Integer
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=MAXPNAMELEN)> _
        Public szPname As String
    End Structure

    Public Structure MIXERLINECONTROLS
        Public cbStruct As Integer
        Public dwLineID As Integer

        Public dwControl As Integer
        Public cControls As Integer
        Public cbmxctrl As Integer

        Public pamxctrl As IntPtr
    End Structure

    Public Enum MUTE_CONTROL
        SPEAKER_MUTE = 7
        LINEIN_MUTE = 8
        MICROPHONE_MUTE = 9
        SYNTHESIZER_MUTE = 10
        COMPACTDISC_MUTE = 11
        WAVEOUT_MUTE = 12
        AUXILIARY_MUTE = 13
    End Enum

    Public Enum VOL_CONTROL
        SPEAKER = 0
        LINEIN = 1
        MICROPHONE = 2
        SYNTHESIZER = 3
        COMPACTDISC = 4
        WAVEOUT = 5
        AUXILIARY = 6
    End Enum

[sapator]

 Public Shared Function GetVolumeControl(ByVal hmixer As Integer, ByVal componentType As Integer, ByVal ctrlType As Integer, ByRef mxc As MIXERCONTROL, ByRef vCurrentVol As Integer) As Boolean
        ' This function attempts to obtain a mixer control.
        ' Returns True if successful.
        Dim mxlc As New MIXERLINECONTROLS
        Dim mxl As New MIXERLINE
        Dim pmxcd As New MIXERCONTROLDETAILS
        Dim du As New MIXERCONTROLDETAILS_UNSIGNED
        mxc = New MIXERCONTROL
        Dim rc As Integer
        Dim retValue As Boolean
        vCurrentVol = -1

        mxl.cbStruct = Marshal.SizeOf(mxl)
        mxl.dwComponentType = componentType

        rc = mixerGetLineInfoA(hmixer, mxl, MIXER_GETLINEINFOF_COMPONENTTYPE)

        If MMSYSERR_NOERROR = rc Then
            Dim sizeofMIXERCONTROL As Integer = 152
            Dim ctrl As Integer = Marshal.SizeOf(GetType(MIXERCONTROL))
            mxlc.pamxctrl = Marshal.AllocCoTaskMem(sizeofMIXERCONTROL)
            mxlc.cbStruct = Marshal.SizeOf(mxlc)
            mxlc.dwLineID = mxl.dwLineID
            mxlc.dwControl = ctrlType
            mxlc.cControls = 1
            mxlc.cbmxctrl = sizeofMIXERCONTROL

            ' Allocate a buffer for the control
            mxc.cbStruct = sizeofMIXERCONTROL

            ' Get the control
            rc = mixerGetLineControlsA(hmixer, mxlc, MIXER_GETLINECONTROLSF_ONEBYTYPE)

            If MMSYSERR_NOERROR = rc Then
                retValue = True
                ' Copy the control into the destination structure
                mxc = DirectCast(Marshal.PtrToStructure(mxlc.pamxctrl, GetType(MIXERCONTROL)), MIXERCONTROL)
            Else
                retValue = False
            End If
            Dim sizeofMIXERCONTROLDETAILS As Integer = Marshal.SizeOf(GetType(MIXERCONTROLDETAILS))
            Dim sizeofMIXERCONTROLDETAILS_UNSIGNED As Integer = Marshal.SizeOf(GetType(MIXERCONTROLDETAILS_UNSIGNED))
            pmxcd.cbStruct = sizeofMIXERCONTROLDETAILS
            pmxcd.dwControlID = mxc.dwControlID


            pmxcd.paDetails = Marshal.AllocCoTaskMem(sizeofMIXERCONTROLDETAILS_UNSIGNED)
            pmxcd.cChannels = 1
            pmxcd.item = 0
            pmxcd.cbDetails = sizeofMIXERCONTROLDETAILS_UNSIGNED

            rc = mixerGetControlDetailsA(hmixer, pmxcd, MIXER_GETCONTROLDETAILSF_VALUE)

            du = DirectCast(Marshal.PtrToStructure(pmxcd.paDetails, GetType(MIXERCONTROLDETAILS_UNSIGNED)), MIXERCONTROLDETAILS_UNSIGNED)

            vCurrentVol = du.dwValue

            Return retValue
        End If

        retValue = False
        Return retValue
    End Function

    Private Shared Function SetVolumeControl(ByVal hmixer As Integer, ByVal mxc As MIXERCONTROL, ByVal volume As Integer) As Boolean
        ' This function sets the value for a volume control.
        ' Returns True if successful

        Dim retValue As Boolean
        Dim rc As Integer
        Dim mxcd As New MIXERCONTROLDETAILS
        Dim vol As New MIXERCONTROLDETAILS_UNSIGNED

        mxcd.item = 0
        mxcd.dwControlID = mxc.dwControlID
        mxcd.cbStruct = Marshal.SizeOf(mxcd)
        mxcd.cbDetails = Marshal.SizeOf(vol)

        ' Allocate a buffer for the control value buffer
        mxcd.cChannels = 1
        vol.dwValue = volume

        ' Copy the data into the control value buffer
        mxcd.paDetails = Marshal.AllocCoTaskMem(Marshal.SizeOf(GetType(MIXERCONTROLDETAILS_UNSIGNED)))
        Marshal.StructureToPtr(vol, mxcd.paDetails, False)

        ' Set the control value
        rc = mixerSetControlDetails(hmixer, mxcd, MIXER_SETCONTROLDETAILSF_VALUE)

        If MMSYSERR_NOERROR = rc Then
            retValue = True
        Else
            retValue = False
        End If
        Return retValue
    End Function

    Public Shared Function GetVolume() As Integer
        Dim mixer As Integer
        Dim volCtrl As New MIXERCONTROL
        Dim currentVol As Integer
        mixerOpen(mixer, 0, 0, 0, 0)
        Dim type As Integer = MIXERCONTROL_CONTROLTYPE_VOLUME
        GetVolumeControl(mixer, MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, type, volCtrl, currentVol)
        mixerClose(mixer)

        Return currentVol
    End Function

    Public Shared Sub SetVolume(ByVal vVolume As Integer)
        Dim mixer As Integer
        Dim volCtrl As New MIXERCONTROL
        Dim currentVol As Integer
        mixerOpen(mixer, 0, 0, 0, 0)
        Dim type As Integer = MIXERCONTROL_CONTROLTYPE_VOLUME
        GetVolumeControl(mixer, MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, type, volCtrl, currentVol)
        If vVolume > volCtrl.lMaximum Then
            vVolume = volCtrl.lMaximum
        End If
        If vVolume < volCtrl.lMinimum Then
            vVolume = volCtrl.lMinimum
        End If
        SetVolumeControl(mixer, volCtrl, vVolume)
        GetVolumeControl(mixer, MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, type, volCtrl, currentVol)
        If vVolume <> currentVol Then
            Throw New Exception("Cannot Set Volume")
        End If
        mixerClose(mixer)
    End Sub
    Public Shared Function SetControlValue(ByVal hMixer As Int32, ByVal mxc As MIXERCONTROL, ByVal NewVolume As Int32) As Boolean

        'This function sets the value for a control. Returns True if successful
        Dim mxcd As MIXERCONTROLDETAILS
        Dim vol As MIXERCONTROLDETAILS_UNSIGNED
        Dim hMem As Int32
        Dim ret As Int32



        Dim sizeofMIXERCONTROLDETAILS As Integer = Marshal.SizeOf(GetType(MIXERCONTROLDETAILS))
        Dim sizeofMIXERCONTROLDETAILS_UNSIGNED As Integer = Marshal.SizeOf(GetType(MIXERCONTROLDETAILS_UNSIGNED))

        mxcd.item = 0
        mxcd.dwControlID = mxc.dwControlID
        mxcd.cbStruct = sizeofMIXERCONTROLDETAILS
        '   mxcd.cbStruct = Len(mxcd)
        mxcd.cbDetails = Marshal.SizeOf(vol)


        ' Allocate a buffer for the control value buffer
        hMem = GlobalAlloc(&H40, Marshal.SizeOf(vol))
        mxcd.paDetails = GlobalLock(hMem)
        mxcd.cChannels = 1

        ' setup value, use percent of range if max is greater than 100
        If mxc.lMaximum > 100 Then
            vol.dwValue = NewVolume * (mxc.lMaximum \ 100)
        Else
            vol.dwValue = NewVolume
        End If
        If vol.dwValue > mxc.lMaximum Then vol.dwValue = mxc.lMaximum
        If vol.dwValue < mxc.lMinimum Then vol.dwValue = mxc.lMinimum



        ' Copy the data into the control value buffer
        CopyPtrFromStruct(mxcd.paDetails, vol, Marshal.SizeOf(vol))

        ' Set the control value

        ret = mixerSetControlDetails(hMixer, mxcd, MIXER_SETCONTROLDETAILSF_VALUE)

        GlobalFree(hMem)

        If ret = MMSYSERR_NOERROR Then SetControlValue = True

    End Function

[sapator]

Public Shared Function GetControlValue(ByVal hMixer As Int32, ByVal mxc As MIXERCONTROL) As Int32

        'This function gets the value for a control.
        Dim mxcd As MIXERCONTROLDETAILS
        Dim vol As MIXERCONTROLDETAILS_UNSIGNED
        Dim hMem As Int32
        Dim ret As Int32




        Dim sizeofMIXERCONTROLDETAILS As Integer = Marshal.SizeOf(GetType(MIXERCONTROLDETAILS))
        Dim sizeofMIXERCONTROLDETAILS_UNSIGNED As Integer = Marshal.SizeOf(GetType(MIXERCONTROLDETAILS_UNSIGNED))
        ' pmxcd.cbStruct = sizeofMIXERCONTROLDETAILS
        ' pmxcd.dwControlID = mxc.dwControlID

        mxcd.item = 0
        mxcd.dwControlID = mxc.dwControlID
        '  mxcd.cbStruct = Len(mxcd)
        mxcd.cbStruct = sizeofMIXERCONTROLDETAILS
        mxcd.cbDetails = Marshal.SizeOf(vol)
        ''mxcd.cbDetails = Len(vol)

        hMem = GlobalAlloc(&H40, Marshal.SizeOf(vol))
        mxcd.paDetails = GlobalLock(hMem)
        mxcd.cChannels = 1

        ' Get the control value

        ret = mixerGetControlDetailsA(hMixer, mxcd, MIXER_GETCONTROLDETAILSF_VALUE)

        ' Copy the data into the control value buffer
        CopyStructFromPtr(vol, mxcd.paDetails, Marshal.SizeOf(vol))

        If mxc.lMaximum > 100 Then
            GetControlValue = (vol.dwValue * 100) / mxc.lMaximum - mxc.lMinimum
        Else
            GetControlValue = vol.dwValue
        End If

        GlobalFree(hMem)

    End Function

    Private Shared Function GetMixerControl(ByVal hMixer As Int32, ByVal componentType As Int32, ByVal ctrlType As Int32, ByRef mxc As MIXERCONTROL) As Int32 ' This function attempts to obtain a mixer control. Returns True if successful.

        Dim mxlc As MIXERLINECONTROLS
        Dim mxl As MIXERLINE
        Dim hMem As Int32
        Dim ret As Int32

        ''mxl.cbStruct = Len(mxl)
        mxl.cbStruct = Marshal.SizeOf(mxl)
        mxl.dwComponentType = componentType

        ' Obtain a line corresponding to the component type
        ret = mixerGetLineInfo(hMixer, mxl, MIXER_GETLINEINFOF_COMPONENTTYPE)

        ''  If ret = MMSYSERR_NOERROR Then
        If ret <> MMSYSERR_NOERROR Then
            ''mxlc.cbStruct = Len(mxlc)
            mxlc.cbStruct = Marshal.SizeOf(mxl)
            mxlc.dwLineID = mxl.dwLineID
            mxlc.dwControl = ctrlType
            mxlc.cControls = 1
            mxlc.cbmxctrl = Marshal.SizeOf(mxc)

            ' Allocate a buffer for the control
            hMem = GlobalAlloc(&H40, Marshal.SizeOf(mxc))
            mxlc.pamxctrl = GlobalLock(hMem)
            mxc.cbStruct = Marshal.SizeOf(mxc)

            ' Get the control
            Dim mc As New mixersetter.MIXERCONTROL
            
            ret = mixerGetLineControls(hMixer, mxlc, MIXER_GETLINECONTROLSF_ONEBYTYPE)

            ''   If ret = MMSYSERR_NOERROR Then
            If ret <> MMSYSERR_NOERROR Then
                GetMixerControl = True

                ''  Marshal.StructureToPtr(mxc, mxlc.pamxctrl, Len(mxc))
                ' Copy the control into the destination structure
                CopyStructFromPtr(mxc, mxlc.pamxctrl, Marshal.SizeOf(mxc))
            Else
                GetMixerControl = False
            End If
            GlobalFree(hMem)
            Exit Function
        End If

        GetMixerControl = False

    End Function



    Public Shared Function SetMute(ByVal Control As MUTE_CONTROL, ByVal MuteState As Boolean) As Boolean

        Dim Mute As Integer

        Mute = MuteState
        SetMute = SetControlValue(hMixerHandle, uMixerControls(Control), Mute)

    End Function

    Public Shared Function GetMute(ByVal Control As MUTE_CONTROL) As Boolean
        GetMute = CBool(-GetControlValue(hMixerHandle, uMixerControls(Control)))

    End Function

    Public Shared Function OpenMixer(ByVal MixerNumber As Int32) As Int32
        Dim ret As Int32

        ' is there a mixer available?

        If MixerNumber < 0 Or MixerNumber > mixerGetNumDevs() - 1 Then Exit Function

        ' open the mixer
        ret = mixerOpen(hMixerHandle, MixerNumber, 0, 0, 0)
        If ret <> MMSYSERR_NOERROR Then Exit Function


        ' get the primary line controls by name, (this does not get all of the controls).

        ' speaker (master) volume

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, MIXERCONTROL_CONTROLTYPE_VOLUME, uMixerControls(VOL_CONTROL.SPEAKER))

        ' microphone volume

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE, MIXERCONTROL_CONTROLTYPE_VOLUME, uMixerControls(VOL_CONTROL.MICROPHONE))

        ' Line volume

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_SRC_AUXILIARY, MIXERCONTROL_CONTROLTYPE_VOLUME, uMixerControls(VOL_CONTROL.AUXILIARY))

        ' CD volume

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_SRC_COMPACTDISC, MIXERCONTROL_CONTROLTYPE_VOLUME, uMixerControls(VOL_CONTROL.COMPACTDISC))

        ' Synthesizer volume

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER, MIXERCONTROL_CONTROLTYPE_VOLUME, uMixerControls(VOL_CONTROL.SYNTHESIZER))

        ' wave volume

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT, MIXERCONTROL_CONTROLTYPE_VOLUME, uMixerControls(VOL_CONTROL.WAVEOUT))

        ' Aux volume

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_SRC_LINE, MIXERCONTROL_CONTROLTYPE_VOLUME, uMixerControls(VOL_CONTROL.LINEIN))

        ' speaker (master) mute

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, MIXERCONTROL_CONTROLTYPE_MUTE, uMixerControls(MUTE_CONTROL.SPEAKER_MUTE))

        ' microphone mute

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE, MIXERCONTROL_CONTROLTYPE_MUTE, uMixerControls(MUTE_CONTROL.MICROPHONE_MUTE))

        ' Line mute

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_SRC_AUXILIARY, MIXERCONTROL_CONTROLTYPE_MUTE, uMixerControls(MUTE_CONTROL.AUXILIARY_MUTE))

        ' CD mute

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_SRC_COMPACTDISC, MIXERCONTROL_CONTROLTYPE_MUTE, uMixerControls(MUTE_CONTROL.COMPACTDISC_MUTE))

        ' Synthesizer mute

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_SRC_SYNTHESIZER, MIXERCONTROL_CONTROLTYPE_MUTE, uMixerControls(MUTE_CONTROL.SYNTHESIZER_MUTE))

        ' wave mute

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT, MIXERCONTROL_CONTROLTYPE_MUTE, uMixerControls(MUTE_CONTROL.WAVEOUT_MUTE))

        ' Aux mute

        ret = GetMixerControl(hMixerHandle, MIXERLINE_COMPONENTTYPE_SRC_LINE, MIXERCONTROL_CONTROLTYPE_MUTE, uMixerControls(MUTE_CONTROL.LINEIN_MUTE))

        ' return the mixer handle
        OpenMixer = True

    End Function

    Public Function CloseMixer() As Int32
        CloseMixer = mixerClose(hMixerHandle)
        hMixerHandle = 0

    End Function


    Public Function SetVolume(ByVal Control As VOL_CONTROL, ByVal NewVolume As Int32) As Int32
        SetVolume = SetControlValue(hMixerHandle, uMixerControls(Control), NewVolume)

    End Function

    Public Function GetVolume(ByVal Control As VOL_CONTROL) As Int32
        GetVolume = GetControlValue(hMixerHandle, uMixerControls(Control))
    End Function

End Class

[sapator]

So i think you had it coming
Good luck.

P.S. Since i have not found a decent mute code i played around a little bit. It will be good for the API gurus here to fix the mute so we can have a solid class.As i've said the MIXERCONTROLDETAILS dwControlID is always zero.Somewhare in here it's not getting the control id correct but i'm to messed up to look into it.
The idea is to set the OpenMixer(0 usually one mixer) first so it can get the controls inside CopyStructFromPtr and then use SetMute to mute the control you want.
So somewhere in the GetMixerControl i'm missing something CopyStructFromPtr was the original.I tryied some marshaling but it's the same result.
Anyway if you like you can look around.

[HongKongCV]

Thanks... I downloaded the code and it seems to work fairly well.

The Get/SetVolume works perfectly and is just what I needed. The SetMute... not so much. But the short work-around is to temporarily set volume to zero and restore it to previous value when mute removed. It's not perfect, by any means, but it's a short work-around.

But this IS what I needed, so thanks.

[sapator]

No problem.
As i said if anyone will take a look and fix the mute then this is a good class to have around.

[HongKongCV]

No promises, but I'll look at it when I get a chance. At the moment I'm slapping a few final features on it before product release.

But thanks for the code, warts and all.

[Amerigo]

mute is easy enough. The following code works well with windows 7 and really mutes the volume so that the volume icon in the taskbar shows that the volume is muted.

Imports System.Runtime.InteropServices

Public Class Mute
    Private Const APPCOMMAND_VOLUME_MUTE As Integer = &H80000
    Private Const WM_APPCOMMAND As Integer = &H319
    Declare Function SendMessageW Lib "user32.dll" (ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr

    Private Sub Mute_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        SendMessageW(Me.Handle, WM_APPCOMMAND, Me.Handle, CType(APPCOMMAND_VOLUME_MUTE, IntPtr))
        Me.Close()
    End Sub
End Class

I'm looking for a simple way to obtain the current volume level (preferably as a percentage) and show on a label without adding the huge bundle of code as above that I keep finding in forums like this.

[sapator]

Aha,interesting but the actual problem was not to do a simple mute.
I was working(and i say was because i got stuffed with other asp.net projects so i don't think i will redo this project) on a class that will mute every control and also mute individual channels.So you could mute p.e. left speaker or on dts p.e. left channel and sub woofer.
Ok back to another week of vacation now....