#include "precomp.h" #include // // private APIs // #define MAX_MICROPHONE_DEVS 10 static MMRESULT mixerGetControlValue ( HMIXER, DWORD *, DWORD, UINT ); static MMRESULT mixerSetControlValue ( HMIXER, DWORD *, DWORD, UINT ); static MMRESULT mixerGetControlId ( HMIXER, DWORD *, DWORD, DWORD ); static MMRESULT mixerGetControlByType ( HMIXER, DWORD, DWORD, MIXERCONTROL *pMixerControl); struct AGCDetails { WORD wMID; // manufacturer ID WORD wPID; // product ID DWORD dwAGCID; // AGC ID }; static const AGCDetails AGCList[] = { // MID PID AGCID {1, 323, 27}, // Creative Labs (NT) {1, 104, 21}, // Creative Labs (NT 5) {2, 409, 27}, // Creative Labs {21, 42, 13}, // Turtle Beach Tropez {132, 3, 2072}, // Crystal MMX {384, 7, 28}, // Xitel Storm 3d PCI {385, 32, 35} // Aztech PCI-331 }; static BOOL GetAGCID(WORD wMID, WORD wPID, DWORD *pdwAGCID) { int nIndex; int nAGCEntries = sizeof(AGCList) / sizeof(AGCDetails); for (nIndex = 0; nIndex < nAGCEntries; nIndex++) { if ( (AGCList[nIndex].wMID == wMID) && (AGCList[nIndex].wPID == wPID)) { *pdwAGCID = AGCList[nIndex].dwAGCID; return TRUE; } } return FALSE; } // // Init // // Enumerate all existing mixers in the system. For each mixer, // we enumerate all lines with destination Speaker and WaveIn. // For each such line, we cache the control id and control value // of volume control. An invalid flag will be tagged to any control // not supported by this mixer. // When an application is finished with all mixers operations, // it must call ReleaseAllMixers to free all memory resources and // mixers. // // THIS MUST BE THE FIRST API TO CALL TO START MIXER OPERATIONS. // // Input: The handle of the window which will handle all callback // messages MM_MIXM_CONTROL_CHANGE and MM_MIXM_LINE_CHANGE. // // Output: TRUE if success; otherwise, FALSE. // BOOL CMixerDevice::Init( HWND hWnd, UINT_PTR uWaveDevId, DWORD dwFlags) { UINT uDstIdx, uSrcIdx, uMixerIdCheck, uMixerIdx; MMRESULT mmr = MMSYSERR_NOERROR; MIXERLINE mlDst, mlSrc; UINT_PTR nMixers, nWaveInDevs, uIndex; //get the mixer device corresponding to the wave device mmr = mixerGetID((HMIXEROBJ)uWaveDevId, &uMixerIdx, dwFlags); if ((mmr != MMSYSERR_NOERROR) && (mmr != MMSYSERR_NODRIVER)) { return FALSE; } // a simple fix for cheesy sound cards that don't make a // direct mapping between waveDevice and mixer device // e.g. MWAVE cards and newer SB NT 4 drivers // If there is only ONE mixer device and if no other waveIn device // uses it, then it is probably valid. if ((mmr == MMSYSERR_NODRIVER) && (dwFlags == MIXER_OBJECTF_WAVEIN)) { nMixers = mixerGetNumDevs(); nWaveInDevs = waveInGetNumDevs(); if (nMixers == 1) { uMixerIdx = 0; for (uIndex = 0; uIndex < nWaveInDevs; uIndex++) { mmr = mixerGetID((HMIXEROBJ)uIndex, &uMixerIdCheck, dwFlags); if ((mmr == MMSYSERR_NOERROR) && (uMixerIdCheck == uMixerIdx)) { return FALSE; // the mixer belongs to another waveIn Device } } } else { return FALSE; } } // open the mixer such that we can get notification messages mmr = mixerOpen ( &m_hMixer, uMixerIdx, (DWORD_PTR) hWnd, 0, (hWnd ? CALLBACK_WINDOW : 0) | MIXER_OBJECTF_MIXER); if (mmr != MMSYSERR_NOERROR) { return FALSE; } // get mixer caps mmr = mixerGetDevCaps (uMixerIdx, &(m_mixerCaps), sizeof (MIXERCAPS)); if ((mmr != MMSYSERR_NOERROR) || (0 == m_mixerCaps.cDestinations)) { mixerClose(m_hMixer); return FALSE; } for (uDstIdx = 0; uDstIdx < m_mixerCaps.cDestinations; uDstIdx++) { ZeroMemory (&mlDst, sizeof (mlDst)); mlDst.cbStruct = sizeof (mlDst); mlDst.dwDestination = uDstIdx; // get the mixer line for this destination mmr = mixerGetLineInfo ((HMIXEROBJ)m_hMixer, &mlDst, MIXER_GETLINEINFOF_DESTINATION | MIXER_OBJECTF_HMIXER); if (mmr != MMSYSERR_NOERROR) continue; // examine the type of this destination line if (((MIXER_OBJECTF_WAVEOUT == dwFlags) && (MIXERLINE_COMPONENTTYPE_DST_SPEAKERS == mlDst.dwComponentType)) || ((MIXER_OBJECTF_WAVEIN == dwFlags) && (MIXERLINE_COMPONENTTYPE_DST_WAVEIN == mlDst.dwComponentType))) { // fill in more info about DstLine m_DstLine.ucChannels = mlDst.cChannels; if (!(mlDst.fdwLine & MIXERLINE_LINEF_DISCONNECTED)) { // get id and value of volume control mmr = mixerGetControlId ( m_hMixer, &m_DstLine.dwControlId, mlDst.dwLineID, MIXERCONTROL_CONTROLTYPE_VOLUME); m_DstLine.fIdValid = (mmr == MMSYSERR_NOERROR); m_DstLine.dwLineId = mlDst.dwLineID; m_DstLine.dwCompType = mlDst.dwComponentType; m_DstLine.dwConnections = mlDst.cConnections; // ----------------------------------------------------- // enumerate all sources for this destination for (uSrcIdx = 0; uSrcIdx < mlDst.cConnections; uSrcIdx++) { // get the info of the line with specific src and dst... ZeroMemory (&mlSrc, sizeof (mlSrc)); mlSrc.cbStruct = sizeof (mlSrc); mlSrc.dwDestination = uDstIdx; mlSrc.dwSource = uSrcIdx; mmr = mixerGetLineInfo ( (HMIXEROBJ)m_hMixer, &mlSrc, MIXER_GETLINEINFOF_SOURCE | MIXER_OBJECTF_HMIXER); if (mmr == MMSYSERR_NOERROR) { if (((MIXERLINE_COMPONENTTYPE_DST_SPEAKERS == mlDst.dwComponentType) && (MIXERLINE_COMPONENTTYPE_SRC_WAVEOUT == mlSrc.dwComponentType)) || ((MIXERLINE_COMPONENTTYPE_DST_WAVEIN == mlDst.dwComponentType) && (MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE == mlSrc.dwComponentType))) { // fill in more info about this source m_SrcLine.ucChannels = mlSrc.cChannels; // get id and value of volume control mmr = mixerGetControlId ( m_hMixer, &m_SrcLine.dwControlId, mlSrc.dwLineID, MIXERCONTROL_CONTROLTYPE_VOLUME); m_SrcLine.fIdValid = (mmr == MMSYSERR_NOERROR); m_SrcLine.dwLineId = mlSrc.dwLineID; m_SrcLine.dwCompType = mlSrc.dwComponentType; m_SrcLine.dwConnections = mlSrc.cConnections; break; } } } } break; } } return TRUE; } CMixerDevice* CMixerDevice::GetMixerForWaveDevice( HWND hWnd, UINT uWaveDevId, DWORD dwFlags) { DBG_SAVE_FILE_LINE CMixerDevice* pMixerDev = new CMixerDevice; if (NULL != pMixerDev) { if (!pMixerDev->Init(hWnd, uWaveDevId, dwFlags)) { delete pMixerDev; pMixerDev = NULL; } } return pMixerDev; } BOOL CMixerDevice::SetMainVolume(DWORD dwVolume) { MMRESULT mmr = MMSYSERR_ERROR; DWORD adwVolume[2]; adwVolume[0] = adwVolume[1] = (DWORD) LOWORD (dwVolume); if (m_DstLine.fIdValid) { mmr = mixerSetControlValue ( m_hMixer, adwVolume, m_DstLine.dwControlId, 2); } return (mmr == MMSYSERR_NOERROR); } BOOL CMixerDevice::SetSubVolume(DWORD dwVolume) { MMRESULT mmr = MMSYSERR_ERROR; DWORD adwVolume[2]; adwVolume[0] = adwVolume[1] = (DWORD) LOWORD (dwVolume); if (m_SrcLine.fIdValid) { mmr = mixerSetControlValue ( m_hMixer, adwVolume, m_SrcLine.dwControlId, m_SrcLine.ucChannels); } return (mmr == MMSYSERR_NOERROR); } // // Gets the volume (0 - 65535) of the master volume // returns TRUE if succesful, // returns FALSE if it fails or if this control is not available // BOOL CMixerDevice::GetMainVolume(LPDWORD pdwVolume) { BOOL fRet = FALSE; if (m_DstLine.fIdValid) { DWORD adwVolume[2]; MMRESULT mmr = ::mixerGetControlValue( m_hMixer, adwVolume, m_DstLine.dwControlId, 2); fRet = (mmr == MMSYSERR_NOERROR); if (fRet) { // BUGBUG: is this the left channel only? *pdwVolume = LOWORD(adwVolume[0]); } } return fRet; } // // Gets the volume (0 - 65535) of the sub volume // returns TRUE if succesful, // returns FALSE if it fails or if this control is not available // BOOL CMixerDevice::GetSubVolume(LPDWORD pdwVolume) { BOOL fRet = FALSE; if (m_SrcLine.fIdValid) { DWORD adwVolume[2]; MMRESULT mmr = ::mixerGetControlValue( m_hMixer, adwVolume, m_SrcLine.dwControlId, m_SrcLine.ucChannels); fRet = (mmr == MMSYSERR_NOERROR); if (fRet) { // BUGBUG: is this the left channel only? *pdwVolume = LOWORD(adwVolume[0]); } } return fRet; } // Return the value of the Auto Gain Control on SB16/AWE32 cards // Returns FALSE if the control is not supported. // pfOn is OUTPUT, OPTIONAL - value of AGC BOOL CMixerDevice::GetAGC(BOOL *pfOn) { MMRESULT mmr; DWORD dwAGCId; DWORD dwValue; if (FALSE == GetAGCID(m_mixerCaps.wMid, m_mixerCaps.wPid, &dwAGCId)) return FALSE; mmr = mixerGetControlValue(m_hMixer, &dwValue, dwAGCId, 1); if (mmr != MMSYSERR_NOERROR) return FALSE; if (pfOn) *pfOn = dwValue; return TRUE; } /* Hack API to turn MIC Auto Gain Control on or off. Its a hack because it only works on SB16/AWE32 cards. */ BOOL CMixerDevice::SetAGC(BOOL fOn) { DWORD dwAGCId; DWORD dwValue; MMRESULT mmr; if (FALSE == GetAGCID(m_mixerCaps.wMid, m_mixerCaps.wPid, &dwAGCId)) return FALSE; mmr = mixerGetControlValue(m_hMixer, &dwValue, dwAGCId, 1); if (mmr != MMSYSERR_NOERROR) return FALSE; if (dwValue == (DWORD)fOn) return TRUE; dwValue = fOn; mmr = mixerSetControlValue(m_hMixer, &dwValue, dwAGCId, 1); return (mmr == MMSYSERR_NOERROR); } BOOL CMixerDevice::EnableMicrophone() { MIXERLINE mixerLine; MIXERCONTROL mixerControl; MIXERCONTROLDETAILS mixerControlDetails, mixerControlDetailsOrig; UINT uIndex, numItems, numMics, numMicsSet, fMicFound; UINT uMicIndex = 0; UINT aMicIndices[MAX_MICROPHONE_DEVS]; MIXERCONTROLDETAILS_LISTTEXT *aListText = NULL; MIXERCONTROLDETAILS_BOOLEAN *aEnableList = NULL; MMRESULT mmr; // check to see if component type is valid (which means the line exists!) // even if the volume control doesn't exist or isn't slidable, // there may still be a select switch if ((m_SrcLine.dwCompType != MIXERLINE_COMPONENTTYPE_SRC_MICROPHONE) || (m_DstLine.dwCompType != MIXERLINE_COMPONENTTYPE_DST_WAVEIN)) { return FALSE; } // try to find the mixer list if ( (MMSYSERR_NOERROR != mixerGetControlByType(m_hMixer, m_DstLine.dwLineId, MIXERCONTROL_CT_CLASS_LIST, &mixerControl)) && (MMSYSERR_NOERROR != mixerGetControlByType(m_hMixer, m_DstLine.dwLineId, MIXERCONTROL_CONTROLTYPE_MIXER, &mixerControl)) && (MMSYSERR_NOERROR != mixerGetControlByType(m_hMixer, m_DstLine.dwLineId, MIXERCONTROL_CONTROLTYPE_MULTIPLESELECT, &mixerControl)) && (MMSYSERR_NOERROR != mixerGetControlByType(m_hMixer, m_DstLine.dwLineId, MIXERCONTROL_CONTROLTYPE_MUX, &mixerControl)) && (MMSYSERR_NOERROR != mixerGetControlByType(m_hMixer, m_DstLine.dwLineId, MIXERCONTROL_CONTROLTYPE_SINGLESELECT, &mixerControl)) ) { TRACE_OUT(("CMixerDevice::EnableMicrophone-Unable to find mixer list!")); return FALSE; } ZeroMemory(&mixerControlDetails, sizeof(MIXERCONTROLDETAILS)); mixerControlDetails.cbStruct = sizeof(MIXERCONTROLDETAILS); mixerControlDetails.dwControlID = mixerControl.dwControlID; if (MIXERCONTROL_CONTROLF_UNIFORM & mixerControl.fdwControl) mixerControlDetails.cChannels = 1; else mixerControlDetails.cChannels = m_DstLine.ucChannels; if (MIXERCONTROL_CONTROLF_MULTIPLE & mixerControl.fdwControl) mixerControlDetails.cMultipleItems = (UINT)mixerControl.cMultipleItems; else mixerControlDetails.cMultipleItems = 1; // weirdness - you have to set cbDetails to the size of a single LISTTEXT item // setting it to anything larger will make the call fail mixerControlDetails.cbDetails = sizeof(MIXERCONTROLDETAILS_LISTTEXT); numItems = mixerControlDetails.cMultipleItems; if (m_DstLine.dwConnections > numItems) numItems = m_DstLine.dwConnections; DBG_SAVE_FILE_LINE aListText = new MIXERCONTROLDETAILS_LISTTEXT[numItems]; DBG_SAVE_FILE_LINE aEnableList = new MIXERCONTROLDETAILS_BOOLEAN[numItems]; if ((aListText == NULL) || (aEnableList == NULL)) { WARNING_OUT(("CMixerDevice::EnableMicrophone-Out of memory")); return FALSE; } ZeroMemory(aListText, sizeof(MIXERCONTROLDETAILS_LISTTEXT)*numItems); ZeroMemory(aEnableList, sizeof(MIXERCONTROLDETAILS_BOOLEAN)*numItems); mixerControlDetails.paDetails = aListText; // preserve the settings, some values will change after this call mixerControlDetailsOrig = mixerControlDetails; // query for the text of the list mmr = mixerGetControlDetails((HMIXEROBJ)m_hMixer, &mixerControlDetails, MIXER_GETCONTROLDETAILSF_LISTTEXT |MIXER_OBJECTF_HMIXER); // some sound cards don't specify CONTROLF_MULTIPLE // try doing what sndvol32 does for MUX controls if (mmr != MMSYSERR_NOERROR) { mixerControlDetails = mixerControlDetailsOrig; mixerControlDetails.cChannels = 1; mixerControlDetails.cMultipleItems = m_DstLine.dwConnections; mixerControlDetailsOrig = mixerControlDetails; mmr = mixerGetControlDetails((HMIXEROBJ)m_hMixer, &mixerControlDetails, MIXER_GETCONTROLDETAILSF_LISTTEXT |MIXER_OBJECTF_HMIXER); } if (mmr != MMSYSERR_NOERROR) { delete [] aListText; delete [] aEnableList; return FALSE; } // enumerate for the microphone numMics = 0; fMicFound = FALSE; for (uIndex = 0; uIndex < mixerControlDetails.cMultipleItems; uIndex++) { // dwParam1 of the listText structure is the LineID of the source // dwParam2 should be the component type, but unfoturnately not // all sound cards obey this rule. ZeroMemory (&mixerLine, sizeof(MIXERLINE)); mixerLine.cbStruct = sizeof(MIXERLINE); mixerLine.dwLineID = aListText[uIndex].dwParam1; mmr = mixerGetLineInfo ((HMIXEROBJ)m_hMixer, &mixerLine, MIXER_GETLINEINFOF_LINEID | MIXER_OBJECTF_HMIXER); if ((mmr == MMSYSERR_NOERROR) && (mixerLine.dwComponentType == m_SrcLine.dwCompType) && (numMics < MAX_MICROPHONE_DEVS)) { aMicIndices[numMics] = uIndex; numMics++; } if (aListText[uIndex].dwParam1 == m_SrcLine.dwLineId) { uMicIndex = uIndex; fMicFound = TRUE; // can't rely on uIndex or uNumMics not zero } } if (fMicFound == FALSE) { delete [] aListText; delete [] aEnableList; return FALSE; } // now we know which position in the array to set, let's do it. mixerControlDetails = mixerControlDetailsOrig; mixerControlDetails.paDetails = aEnableList; mixerControlDetails.cbDetails = sizeof(MIXERCONTROLDETAILS_BOOLEAN); // find out what's already marked as set. mmr = mixerGetControlDetails((HMIXEROBJ)m_hMixer, &mixerControlDetails, MIXER_SETCONTROLDETAILSF_VALUE|MIXER_OBJECTF_HMIXER); if ((mmr == MMSYSERR_NOERROR) && (aEnableList[uMicIndex].fValue != 1)) { // how many microphone's are already enabled ? // if another microphone is already enabled and if the device is MUX type // we won't attempt to turn one on. numMicsSet = 0; for (uIndex = 0; uIndex < numMics; uIndex++) { if ((aEnableList[aMicIndices[uIndex]].fValue == 1) && (uIndex != uMicIndex)) { numMicsSet++; } } if ( (mixerControl.dwControlType == MIXERCONTROL_CONTROLTYPE_MUX) ||(mixerControl.dwControlType == MIXERCONTROL_CONTROLTYPE_SINGLESELECT)) { ZeroMemory(aEnableList, sizeof(aEnableList)*numItems); aEnableList[uMicIndex].fValue = 1; if (numMicsSet == 0) { mmr = mixerSetControlDetails((HMIXEROBJ)m_hMixer, &mixerControlDetails, MIXER_SETCONTROLDETAILSF_VALUE|MIXER_OBJECTF_HMIXER); } else { mmr = MMSYSERR_ERROR; // a mike has already been enabled } } else { mixerControlDetails = mixerControlDetailsOrig; mixerControlDetails.paDetails = aEnableList; mixerControlDetails.cbDetails = sizeof(MIXERCONTROLDETAILS_BOOLEAN); aEnableList[uMicIndex].fValue = 1; mmr = mixerSetControlDetails((HMIXEROBJ)m_hMixer, &mixerControlDetails, MIXER_GETCONTROLDETAILSF_VALUE|MIXER_OBJECTF_HMIXER); } } delete []aEnableList; delete []aListText; return (mmr == MMSYSERR_NOERROR); } BOOL CMixerDevice::UnMuteVolume() { MIXERCONTROL mixerControl; MIXERCONTROLDETAILS mixerControlDetails; MIXERCONTROLDETAILS_BOOLEAN mcdb; MMRESULT mmrMaster, mmrSub; // try to unmute the master volume // this could be used on both the recording and playback mixers mmrMaster = mixerGetControlByType(m_hMixer, m_DstLine.dwLineId, MIXERCONTROL_CONTROLTYPE_MUTE, &mixerControl); if (mmrMaster == MMSYSERR_NOERROR) { ZeroMemory(&mixerControlDetails, sizeof(MIXERCONTROLDETAILS)); mixerControlDetails.cbStruct = sizeof(MIXERCONTROLDETAILS); mixerControlDetails.dwControlID = mixerControl.dwControlID; mixerControlDetails.cChannels = 1; mixerControlDetails.cMultipleItems = 0; mcdb.fValue = 0; mixerControlDetails.paDetails = &mcdb; mixerControlDetails.cbDetails = sizeof(MIXERCONTROLDETAILS_BOOLEAN); mmrMaster = mixerSetControlDetails((HMIXEROBJ)m_hMixer, &mixerControlDetails, MIXER_SETCONTROLDETAILSF_VALUE|MIXER_OBJECTF_HMIXER); } // only try to unmute waveOut if ( (m_DstLine.dwCompType != MIXERLINE_COMPONENTTYPE_DST_SPEAKERS) || (m_SrcLine.dwCompType == 0)) { return (mmrMaster == MMSYSERR_NOERROR); } mmrSub = mixerGetControlByType(m_hMixer, m_SrcLine.dwLineId, MIXERCONTROL_CONTROLTYPE_MUTE, &mixerControl); if (mmrSub == MMSYSERR_NOERROR) { ZeroMemory(&mixerControlDetails, sizeof(MIXERCONTROLDETAILS)); mixerControlDetails.cbStruct = sizeof(MIXERCONTROLDETAILS); mixerControlDetails.dwControlID = mixerControl.dwControlID; mixerControlDetails.cChannels = 1; mixerControlDetails.cMultipleItems = 0; mcdb.fValue = 0; mixerControlDetails.paDetails = &mcdb; mixerControlDetails.cbDetails = sizeof(MIXERCONTROLDETAILS_BOOLEAN); mmrSub = mixerSetControlDetails((HMIXEROBJ)m_hMixer, &mixerControlDetails, MIXER_SETCONTROLDETAILSF_VALUE|MIXER_OBJECTF_HMIXER); } return ((mmrSub == MMSYSERR_NOERROR) || (mmrMaster == MMSYSERR_NOERROR)); } ////////////////////////////////////////////////// // // The following are private APIs // static MMRESULT mixerGetControlValue ( HMIXER hMixer, DWORD *pdwValue, DWORD dwControlId, UINT ucChannels ) { MIXERCONTROLDETAILS mxcd; MMRESULT mmr; ZeroMemory (&mxcd, sizeof (mxcd)); mxcd.cbStruct = sizeof (mxcd); mxcd.dwControlID = dwControlId; mxcd.cChannels = ucChannels; mxcd.cbDetails = sizeof (DWORD); mxcd.paDetails = (PVOID) pdwValue; mmr = mixerGetControlDetails ((HMIXEROBJ) hMixer, &mxcd, MIXER_GETCONTROLDETAILSF_VALUE | MIXER_OBJECTF_HMIXER); return mmr; } static MMRESULT mixerSetControlValue ( HMIXER hMixer, DWORD *pdwValue, DWORD dwControlId, UINT ucChannels ) { MIXERCONTROLDETAILS mxcd; MMRESULT mmr; ZeroMemory (&mxcd, sizeof (mxcd)); mxcd.cbStruct = sizeof (mxcd); mxcd.dwControlID = dwControlId; mxcd.cChannels = ucChannels; mxcd.cbDetails = sizeof (DWORD); mxcd.paDetails = (PVOID) pdwValue; mmr = mixerSetControlDetails ((HMIXEROBJ) hMixer, &mxcd, MIXER_SETCONTROLDETAILSF_VALUE | MIXER_OBJECTF_HMIXER); return mmr; } static MMRESULT mixerGetControlId ( HMIXER hMixer, DWORD *pdwControlId, DWORD dwLineId, DWORD dwControlType ) { MIXERLINECONTROLS mxlc; MIXERCONTROL mxc; MMRESULT mmr; ZeroMemory (&mxlc, sizeof (mxlc)); ZeroMemory (&mxc, sizeof (mxc)); mxlc.cbStruct = sizeof (mxlc); mxlc.dwLineID = dwLineId; mxlc.dwControlType = dwControlType; mxlc.cControls = 1; mxlc.cbmxctrl = sizeof (mxc); mxlc.pamxctrl = &mxc; mmr = mixerGetLineControls ((HMIXEROBJ) hMixer, &mxlc, MIXER_GETLINECONTROLSF_ONEBYTYPE | MIXER_OBJECTF_HMIXER); *pdwControlId = mxc.dwControlID; return mmr; } // similar to above, except returns the whole control static MMRESULT mixerGetControlByType ( HMIXER hMixer, DWORD dwLineId, DWORD dwControlType, MIXERCONTROL *pMixerControl) { MIXERLINECONTROLS mxlc; MMRESULT mmr; ZeroMemory (&mxlc, sizeof (mxlc)); ZeroMemory (pMixerControl, sizeof (MIXERCONTROL)); mxlc.cbStruct = sizeof (mxlc); mxlc.dwLineID = dwLineId; mxlc.dwControlType = dwControlType; mxlc.cControls = 1; mxlc.cbmxctrl = sizeof (MIXERCONTROL); mxlc.pamxctrl = pMixerControl; mmr = mixerGetLineControls ((HMIXEROBJ) hMixer, &mxlc, MIXER_GETLINECONTROLSF_ONEBYTYPE | MIXER_OBJECTF_HMIXER); return mmr; } // IUnknown stuff ULONG __stdcall CMixerDevice::AddRef() { InterlockedIncrement(&m_lRefCount); return m_lRefCount; } ULONG __stdcall CMixerDevice::Release() { if (0 == InterlockedDecrement(&m_lRefCount)) { delete this; return 0; } return m_lRefCount; } HRESULT __stdcall CMixerDevice::QueryInterface(const IID& iid, void **ppVoid) { if ((iid == IID_IUnknown) || (iid == IID_IMixer)) { *ppVoid = this; } else { *ppVoid = NULL; return E_NOINTERFACE; } AddRef(); return S_OK; }