static ALCboolean DSoundOpenPlayback(ALCdevice *device, const ALCchar *deviceName)
{
    DSoundData *pData = NULL;
    LPGUID guid = NULL;
    HRESULT hr;

    if(!DSoundLoad())
        return ALC_FALSE;

    if(!deviceName)
        deviceName = dsDevice;
    else if(strcmp(deviceName, dsDevice) != 0)
    {
        ALuint i;

        if(!DeviceList)
        {
            hr = pDirectSoundEnumerateA(DSoundEnumDevices, NULL);
            if(FAILED(hr))
                AL_PRINT("Error enumerating DirectSound devices (%#x)!\n", (unsigned int)hr);
        }

        for(i = 0; i < NumDevices; i++)
        {
            if(strcmp(deviceName, DeviceList[i].name) == 0)
            {
                if(i > 0)
                    guid = &DeviceList[i].guid;
                break;
            }
        }
        if(i == NumDevices)
            return ALC_FALSE;
    }

    //Initialise requested device
    pData = calloc(1, sizeof(DSoundData));
    if(!pData)
    {
        alcSetError(device, ALC_OUT_OF_MEMORY);
        return ALC_FALSE;
    }

    //DirectSound Init code
    hr = pDirectSoundCreate(guid, &pData->lpDS, NULL);
    if(SUCCEEDED(hr))
        hr = IDirectSound_SetCooperativeLevel(pData->lpDS, GetForegroundWindow(), DSSCL_PRIORITY);
    if(FAILED(hr))
    {
        if(pData->lpDS)
            IDirectSound_Release(pData->lpDS);
        free(pData);
        AL_PRINT("Device init failed: 0x%08lx\n", hr);
        return ALC_FALSE;
    }

    device->szDeviceName = strdup(deviceName);
    device->ExtraData = pData;
    return ALC_TRUE;
}

static gboolean
gst_directsound_sink_open (GstAudioSink * asink)
{
  GstDirectSoundSink *dsoundsink;
  HRESULT hRes;

  dsoundsink = GST_DIRECTSOUND_SINK (asink);

  /* create and initialize a DirecSound object */
  if (FAILED (hRes = DirectSoundCreate (NULL, &dsoundsink->pDS, NULL))) {
    GST_ELEMENT_ERROR (dsoundsink, RESOURCE, OPEN_READ,
        ("gst_directsound_sink_open: DirectSoundCreate: %s",
            DXGetErrorString9 (hRes)), (NULL));
    return FALSE;
  }

  if (FAILED (hRes = IDirectSound_SetCooperativeLevel (dsoundsink->pDS,
              GetDesktopWindow (), DSSCL_PRIORITY))) {
    GST_ELEMENT_ERROR (dsoundsink, RESOURCE, OPEN_READ,
        ("gst_directsound_sink_open: IDirectSound_SetCooperativeLevel: %s",
            DXGetErrorString9 (hRes)), (NULL));
    return FALSE;
  }

  return TRUE;
}

static void
FreeSound (void)
{
	if (pDSBuf) {
		IDirectSoundBuffer_Stop (pDSBuf);
		IDirectSound_Release (pDSBuf);
	}
// release primary buffer only if it's not also the mixing buffer we just released
	if (pDSPBuf && (pDSBuf != pDSPBuf)) {
		IDirectSound_Release (pDSPBuf);
	}

	if (pDS) {
		IDirectSound_SetCooperativeLevel (pDS, mainwindow, DSSCL_NORMAL);
		IDirectSound_Release (pDS);
	}
	pDS = NULL;
	pDSBuf = NULL;
	pDSPBuf = NULL;
	hWaveOut = 0;
	hData = 0;
	hWaveHdr = 0;
	lpData = NULL;
	lpWaveHdr = NULL;
}

void m1sdr_PlayStart(void)
{
	waveLogStart();

	IDirectSound_SetCooperativeLevel(lpDS, GetForegroundWindow(), DSSCL_PRIORITY);
	
	IDirectSoundBuffer_SetCurrentPosition(lpSecB, 0);
	IDirectSoundBuffer_Play(lpSecB, 0, 0, DSBPLAY_LOOPING);
}

static ALCboolean DSoundOpenPlayback(ALCdevice *device, const ALCchar *deviceName)
{
    DSoundData *pData = NULL;
    LPGUID guid = NULL;
    HRESULT hr;

    if(!deviceName)
        deviceName = dsDevice;
    else if(strcmp(deviceName, dsDevice) != 0)
    {
        ALuint i;
        for(i = 0;i < NumDevices;i++)
        {
            if(strcmp(deviceName, DeviceList[i].name) == 0)
            {
                guid = &DeviceList[i].guid;
                break;
            }
        }
        if(i == NumDevices)
            return ALC_FALSE;
    }

    DSoundLoad();
    if(ds_handle == NULL)
        return ALC_FALSE;

    //Initialise requested device

    pData = calloc(1, sizeof(DSoundData));
    if(!pData)
    {
        alcSetError(ALC_OUT_OF_MEMORY);
        DSoundUnload();
        return ALC_FALSE;
    }

    //DirectSound Init code
    hr = pDirectSoundCreate(guid, &pData->lpDS, NULL);
    if(SUCCEEDED(hr))
        hr = IDirectSound_SetCooperativeLevel(pData->lpDS, GetForegroundWindow(), DSSCL_PRIORITY);
    if(FAILED(hr))
    {
        if(pData->lpDS)
            IDirectSound_Release(pData->lpDS);
        free(pData);
        DSoundUnload();
        return ALC_FALSE;
    }

    device->szDeviceName = strdup(deviceName);
    device->ExtraData = pData;
    return ALC_TRUE;
}

/*
	FreeSound
*/
void
FreeSound (void)
{
	int         i;

	if (pDSBuf) {
		IDirectSoundBuffer_Stop (pDSBuf);
		IDirectSound_Release (pDSBuf);
	}
// only release primary buffer if it's not also the mixing buffer we just released
	if (pDSPBuf && (pDSBuf != pDSPBuf)) {
		IDirectSound_Release (pDSPBuf);
	}

	if (pDS) {
		IDirectSound_SetCooperativeLevel (pDS, mainwindow, DSSCL_NORMAL);
		IDirectSound_Release (pDS);
	}

	if (hWaveOut) {
		waveOutReset (hWaveOut);

		if (lpWaveHdr) {
			for (i = 0; i < WAV_BUFFERS; i++)
				waveOutUnprepareHeader (hWaveOut, lpWaveHdr + i,
										sizeof (WAVEHDR));
		}

		waveOutClose (hWaveOut);

		if (hWaveHdr) {
			GlobalUnlock (hWaveHdr);
			GlobalFree (hWaveHdr);
		}

		if (hData) {
			GlobalUnlock (hData);
			GlobalFree (hData);
		}

	}

	pDS = NULL;
	pDSBuf = NULL;
	pDSPBuf = NULL;
	hWaveOut = 0;
	hData = 0;
	hWaveHdr = 0;
	lpData = NULL;
	lpWaveHdr = NULL;
	dsound_init = false;
	wav_init = false;
}

BOOL SSInit(HWND hWnd, int channels, unsigned flags)
{
	LPDIRECTSOUNDBUFFER lpPrimaryBuffer;
	LPDIRECTSOUND lpDS;
	DSBUFFERDESC dsbd;

	if (SSMixer.lpds) return TRUE;

//	Perform Direct Sound Initialization
	if (DirectSoundCreate(NULL, &lpDS, NULL) != DS_OK) 
		return FALSE;

	SSMixer.lpds = lpDS;

	if (IDirectSound_SetCooperativeLevel(lpDS, hWnd, DSSCL_NORMAL) != DS_OK) {
		SSDestroy();
		return FALSE;
	}

//	Start Mixer
	memset(&dsbd, 0, sizeof(DSBUFFERDESC));
	dsbd.dwSize = sizeof(DSBUFFERDESC);
	dsbd.dwFlags = DSBCAPS_PRIMARYBUFFER;
	if (IDirectSound_CreateSoundBuffer(SSMixer.lpds, &dsbd, &lpPrimaryBuffer, NULL) == DS_OK) {
		if (IDirectSoundBuffer_Play(lpPrimaryBuffer, 0, 0, DSBPLAY_LOOPING) != DS_OK) {
			IDirectSoundBuffer_Release(lpPrimaryBuffer);
			SSDestroy();
			return FALSE;
		}
		IDirectSoundBuffer_Release(lpPrimaryBuffer);
	}
	else {
		SSDestroy();
		return FALSE;
	}


//	Finish initializing SSMixer.
	SSMixer.ch_cur = 0;
	SSMixer.ch_list = (SSoundBuffer *)malloc(sizeof(SSoundBuffer)*channels);
	if (!SSMixer.ch_list) return FALSE;
	
	memset(SSMixer.ch_list, 0, sizeof(SSoundBuffer)*channels);
	
	SSMixer.ch_num = channels;

//	Determine Sound technology and volume caps
	waveOutGetVolume((HWAVEOUT)WAVE_MAPPER, (LPDWORD)&SSMixer.old_master_vol);
//	waveOutSetVolume((HWAVEOUT)WAVE_MAPPER, 0x40004000);
	return TRUE;
}

int pest_open( HWND win ){
	HMODULE lib;
	DIRECTSOUNDCREATE dsound_create;
	WAVEFORMATEX format;
	DSBUFFERDESC desc_primary, desc_secondary;

	lib = (HMODULE)LoadLibrary("dsound.dll");
	if(lib==NULL) return FALSE;

	dsound_create = (DIRECTSOUNDCREATE)GetProcAddress(lib, "DirectSoundCreate");
	if(dsound_create==NULL) return FALSE;
	FreeLibrary(lib);

	if( dsound_create( NULL, &dsound, NULL )!= DS_OK ) return FALSE;

	if( IDirectSound_SetCooperativeLevel( dsound, win, DSSCL_EXCLUSIVE | DSSCL_PRIORITY ) != DS_OK ) return FALSE;

	memset( &desc_primary, 0, sizeof(DSBUFFERDESC) );
	desc_primary.dwSize = sizeof(DSBUFFERDESC);
	desc_primary.dwFlags = DSBCAPS_PRIMARYBUFFER | DSBCAPS_STICKYFOCUS;
	
	if(IDirectSound_CreateSoundBuffer( dsound, &desc_primary, &primary, NULL )!=DS_OK) return FALSE;

	memset( &format, 0, sizeof(WAVEFORMATEX) );
	format.wFormatTag = WAVE_FORMAT_PCM;
	format.nChannels = 2;
	format.nSamplesPerSec = 44100;
	format.nAvgBytesPerSec = 44100 * 4;
	format.nBlockAlign = 4;
	format.wBitsPerSample = 16;

	if( IDirectSoundBuffer_SetFormat( primary, &format )!= DS_OK) return FALSE;

	memset( &desc_secondary, 0, sizeof(DSBUFFERDESC) );
	desc_secondary.dwSize = sizeof(DSBUFFERDESC);
	desc_secondary.dwFlags = DSBCAPS_GLOBALFOCUS | DSBCAPS_GETCURRENTPOSITION2;
	desc_secondary.lpwfxFormat = &format;
	desc_secondary.dwBufferBytes = 2*2*BUFFER_LEN;

	if(IDirectSound_CreateSoundBuffer( dsound, &desc_secondary, &secondary, NULL )!=DS_OK) return FALSE;

	InitializeCriticalSection(&critical);

	return TRUE;
}

int DirectSoundInit()
{
   HRESULT hr;
   HWND hWnd;

	LoadDsound();	
   hr = pDirectSoundCreate(NULL, &lpDirectSound, NULL);
   if( hr != DS_OK ) 
	   return 0;
   hWnd = GetForegroundWindow();
   // establecer el nivel de cooperacion
   hr = IDirectSound_SetCooperativeLevel(lpDirectSound,hWnd, DSSCL_NORMAL );
   if( hr != DS_OK)
		return 0;
   return 1;

 
}

/*
 * DirectSoundを初期化する
 */
BOOL DSInitialize(HWND hWnd)
{
	HRESULT hRet;
	uintptr_t t;

	/* IDirectSoundのインスタンスを取得して初期化する */
	hRet = CoCreateInstance(&CLSID_DirectSound,
							NULL,
							CLSCTX_INPROC_SERVER,
							&IID_IDirectSound,
							(void **)&pDS);
	if(hRet != S_OK || pDS == NULL)
		return FALSE;

	/* COMオブジェクトを初期化する */
	IDirectSound_Initialize(pDS, NULL);

	/* 協調レベルを設定する */
	hRet = IDirectSound_SetCooperativeLevel(pDS, hWnd, DSSCL_PRIORITY);
	if(hRet != DS_OK)
		return FALSE;

	/* プライマリバッファのフォーマットを設定する */
	if(!CreatePrimaryBuffer())
		return FALSE;

	/* セカンダリバッファを作成する */
	if(!CreateSecondaryBuffers())
		return FALSE;

	/* イベントスレッドへの終了通知用のイベントを作成する */
	hQuitEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
	if(hQuitEvent == NULL)
		return FALSE;

	/* DirectSoundの再生位置通知を受け取るスレッドを開始する */
	t = _beginthread(EventThread, 0, NULL);
	if(t == (unsigned long)-1)
		return FALSE;

	hEventThread = (HANDLE)t;
	return TRUE;
}

/* Initialise audio devices. */
int digi_init()
{
 HRESULT hr;
 
 if (!digi_initialised && g_hWnd){

	 memset(&waveformat, 0, sizeof(waveformat));
	 waveformat.wFormatTag=WAVE_FORMAT_PCM;
	 waveformat.wBitsPerSample=8;
	 waveformat.nChannels = 1;
	 waveformat.nSamplesPerSec = 11025;
	 waveformat.nBlockAlign =
                    waveformat.nChannels * (waveformat.wBitsPerSample/8);
	 waveformat.nAvgBytesPerSec =
                    waveformat.nSamplesPerSec * waveformat.nBlockAlign; 

	  if ((hr = DirectSoundCreate(NULL, &lpds, NULL)) != DS_OK)
	   return -1;

	  if ((hr = IDirectSound_SetCooperativeLevel(lpds, g_hWnd, DSSCL_PRIORITY)) //hWndMain
	       != DS_OK)
	   {
	    IDirectSound_Release(lpds);
	    return -1;
	   }
	
	 memset(&dsbd, 0, sizeof(dsbd));
	 dsbd.dwSize = sizeof(dsbd);
	 dsbd.dwFlags = (DSBCAPS_CTRLFREQUENCY|DSBCAPS_CTRLPAN|DSBCAPS_CTRLVOLUME) | DSBCAPS_GETCURRENTPOSITION2;
	 dsbd.dwBufferBytes = 8192;
	 dsbd.dwReserved=0;
	 dsbd.lpwfxFormat = &waveformat;

	 digi_initialised = 1;
}

	if (!digi_atexit_initialised){
		atexit(digi_close);
		digi_atexit_initialised=1;
	}
 return 0;
}

static int dsound_open (dsound *s)
{
    HRESULT hr;
    HWND hwnd;

    hwnd = GetForegroundWindow ();
    hr = IDirectSound_SetCooperativeLevel (
        s->dsound,
        hwnd,
        DSSCL_PRIORITY
        );

    if (FAILED (hr)) {
        dsound_logerr (hr, "Could not set cooperative level for window %p\n",
                       hwnd);
        return -1;
    }

    return 0;
}

//open the dsound interface.
static BOOL setupSoundPlay(VOID)
{
	HWND		hwnd;
	HRESULT     hr;

	hwnd = frameGetWinHandle();

	hr =DirectSoundCreate(NULL, &lpDirectSound, NULL);							// create dsound object
	if (hr != DS_OK)
	{
		DBPRINTF(("NETPLAY Failed to create dsound interface.\n"));	
		return (FALSE);
	}

	hr =IDirectSound_SetCooperativeLevel(lpDirectSound, hwnd, DSSCL_PRIORITY);	// Set coop level
	if (hr != DS_OK)
	{
		DBPRINTF(("NETPLAY Failed to create playback buffer..\n"));	
		return (FALSE);
	}

	IDirectSound_Compact(lpDirectSound);										// compact things 
	return (TRUE);
}

static ALCenum DSoundOpenPlayback(ALCdevice *device, const ALCchar *deviceName)
{
    DSoundPlaybackData *data = NULL;
    LPGUID guid = NULL;
    HRESULT hr;

    if(!PlaybackDeviceList)
    {
        hr = DirectSoundEnumerateA(DSoundEnumPlaybackDevices, NULL);
        if(FAILED(hr))
            ERR("Error enumerating DirectSound devices (%#x)!\n", (unsigned int)hr);
    }

    if(!deviceName && NumPlaybackDevices > 0)
    {
        deviceName = PlaybackDeviceList[0].name;
        guid = &PlaybackDeviceList[0].guid;
    }
    else
    {
        ALuint i;

        for(i = 0;i < NumPlaybackDevices;i++)
        {
            if(strcmp(deviceName, PlaybackDeviceList[i].name) == 0)
            {
                guid = &PlaybackDeviceList[i].guid;
                break;
            }
        }
        if(i == NumPlaybackDevices)
            return ALC_INVALID_VALUE;
    }

    //Initialise requested device
    data = calloc(1, sizeof(DSoundPlaybackData));
    if(!data)
        return ALC_OUT_OF_MEMORY;

    hr = DS_OK;
    data->NotifyEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
    if(data->NotifyEvent == NULL)
        hr = E_FAIL;

    //DirectSound Init code
    if(SUCCEEDED(hr))
        hr = DirectSoundCreate(guid, &data->DS, NULL);
    if(SUCCEEDED(hr))
        hr = IDirectSound_SetCooperativeLevel(data->DS, GetForegroundWindow(), DSSCL_PRIORITY);
    if(FAILED(hr))
    {
        if(data->DS)
            IDirectSound_Release(data->DS);
        if(data->NotifyEvent)
            CloseHandle(data->NotifyEvent);
        free(data);
        ERR("Device init failed: 0x%08lx\n", hr);
        return ALC_INVALID_VALUE;
    }

    device->DeviceName = strdup(deviceName);
    device->ExtraData = data;
    return ALC_NO_ERROR;
}

INT16 m1sdr_Init(int sample_rate)
{
	DSBUFFERDESC	dsbuf;
	WAVEFORMATEX	format;

	if (!s32SoundEnable) return(0);

	nDSoundSamRate = sample_rate;

	samples = NULL;

	lpDS = NULL;
	lpPDSB = NULL;
	lpSecB = NULL;

	// Calculate the Seg Length and Loop length
	// (round to nearest sample)
	nDSoundSegLen=(nDSoundSamRate*10+(nDSoundFps>>1))/nDSoundFps;
	cbLoopLen=(nDSoundSegLen*nDSoundSegCount)<<2;

	// create an IDirectSound COM object

	if (DS_OK != DirectSoundCreate(NULL, &lpDS, NULL))
	{
    	printf("Unable to create DirectSound object!\n");
		return(0);
	}

	// set cooperative level where we need it

	if (DS_OK != IDirectSound_SetCooperativeLevel(lpDS, GetForegroundWindow(), DSSCL_PRIORITY))
	{
    	printf("Unable to set cooperative level!\n");
		return(0);
	}

	// now create a primary sound buffer
	memset(&format, 0, sizeof(format));
	format.wFormatTag = WAVE_FORMAT_PCM;
	format.nChannels = 2;
	format.wBitsPerSample = 16;
	format.nSamplesPerSec = nDSoundSamRate;
	format.nBlockAlign = 4;	// stereo 16-bit
	format.cbSize = 0;
  	format.nAvgBytesPerSec=format.nSamplesPerSec*format.nBlockAlign;

	memset(&dsbuf, 0, sizeof(dsbuf));
	dsbuf.dwSize = sizeof(DSBUFFERDESC);
	dsbuf.dwFlags = DSBCAPS_PRIMARYBUFFER;
	dsbuf.dwBufferBytes = 0;
	dsbuf.lpwfxFormat = NULL;

	if (DS_OK != IDirectSound_CreateSoundBuffer(lpDS, &dsbuf, &lpPDSB, NULL))
	{
    	printf("Unable to create primary buffer!");
		return(0);		
	}

	// and set it's format how we want
	
	if (DS_OK != IDirectSoundBuffer_SetFormat(lpPDSB, &format))		
	{
    	printf("Unable to set primary buffer format!\n");
		return(0);
	}

	// start the primary buffer playing now so we get
	// minimal lag when we trigger our secondary buffer

	IDirectSoundBuffer_Play(lpPDSB, 0, 0, DSBPLAY_LOOPING);

	// that's done, now let's create our secondary buffer

    memset(&dsbuf, 0, sizeof(DSBUFFERDESC));
    dsbuf.dwSize = sizeof(DSBUFFERDESC);
	// we'll take default controls for this one
    dsbuf.dwFlags = DSBCAPS_GLOBALFOCUS | DSBCAPS_GETCURRENTPOSITION2 | DSBCAPS_CTRLPOSITIONNOTIFY; 
    dsbuf.dwBufferBytes = cbLoopLen;
    dsbuf.lpwfxFormat = (LPWAVEFORMATEX)&format;
	
	if (DS_OK != IDirectSound_CreateSoundBuffer(lpDS, &dsbuf, &lpSecB, NULL))
	{
    	printf("Unable to create secondary buffer\n");
		return(0);
	}

	// ok, cool, we're ready to go!
	// blank out the entire sound buffer
	{
		LPVOID ptr; DWORD len;

		IDirectSoundBuffer_Lock(lpSecB, 0, 0, &ptr, &len, NULL, NULL, DSBLOCK_ENTIREBUFFER);
		ZeroMemory(ptr, len);
		IDirectSoundBuffer_Unlock(lpSecB, ptr, len, 0, 0);
	}

	// allocate and zero our local buffer
	samples = (INT16 *)malloc(nDSoundSegLen<<2);
	ZeroMemory(samples, nDSoundSegLen<<2);

//.........这里部分代码省略.........

static void *dsound_init(const char *device, unsigned rate, unsigned latency)
{
   WAVEFORMATEX wfx      = {0};
   DSBUFFERDESC bufdesc  = {0};
   struct dsound_dev dev = {0};
   dsound_t          *ds = (dsound_t*)calloc(1, sizeof(*ds));

   if (!ds)
      goto error;

   InitializeCriticalSection(&ds->crit);

   if (device)
      dev.device = strtoul(device, NULL, 0);

   RARCH_LOG("DirectSound devices:\n");
#ifndef _XBOX
   DirectSoundEnumerate(enumerate_cb, &dev);
#endif

   if (DirectSoundCreate(dev.guid, &ds->ds, NULL) != DS_OK)
      goto error;

#ifndef _XBOX
   if (IDirectSound_SetCooperativeLevel(ds->ds, GetDesktopWindow(), DSSCL_PRIORITY) != DS_OK)
      goto error;
#endif

   wfx.wFormatTag        = WAVE_FORMAT_PCM;
   wfx.nChannels         = 2;
   wfx.nSamplesPerSec    = rate;
   wfx.wBitsPerSample    = 16;
   wfx.nBlockAlign       = 2 * sizeof(int16_t);
   wfx.nAvgBytesPerSec   = rate * 2 * sizeof(int16_t);

   ds->buffer_size       = (latency * wfx.nAvgBytesPerSec) / 1000;
   ds->buffer_size      /= CHUNK_SIZE;
   ds->buffer_size      *= CHUNK_SIZE;
   if (ds->buffer_size < 4 * CHUNK_SIZE)
      ds->buffer_size    = 4 * CHUNK_SIZE;

   RARCH_LOG("[DirectSound]: Setting buffer size of %u bytes\n", ds->buffer_size);
   RARCH_LOG("[DirectSound]: Latency = %u ms\n", (unsigned)((1000 * ds->buffer_size) / wfx.nAvgBytesPerSec));

   bufdesc.dwSize        = sizeof(DSBUFFERDESC);
   bufdesc.dwFlags       = 0;
#ifndef _XBOX
   bufdesc.dwFlags       = DSBCAPS_GETCURRENTPOSITION2 | DSBCAPS_GLOBALFOCUS;
#endif
   bufdesc.dwBufferBytes = ds->buffer_size;
   bufdesc.lpwfxFormat   = &wfx;

   ds->event = CreateEvent(NULL, false, false, NULL);
   if (!ds->event)
      goto error;

   ds->buffer = fifo_new(4 * 1024);
   if (!ds->buffer)
      goto error;

   if (IDirectSound_CreateSoundBuffer(ds->ds, &bufdesc, &ds->dsb, 0) != DS_OK)
      goto error;

   IDirectSoundBuffer_SetVolume(ds->dsb, DSBVOLUME_MAX);
   IDirectSoundBuffer_SetCurrentPosition(ds->dsb, 0);

   dsound_clear_buffer(ds);

   if (IDirectSoundBuffer_Play(ds->dsb, 0, 0, DSBPLAY_LOOPING) != DS_OK)
      goto error;

   if (!dsound_start_thread(ds))
      goto error;

   return ds;

error:
   RARCH_ERR("[DirectSound] Error occured in init.\n");
   dsound_free(ds);
   return NULL;
}

HRESULT DSoundRender_create(IUnknown * pUnkOuter, LPVOID * ppv)
{
    HRESULT hr;
    PIN_INFO piInput;
    DSoundRenderImpl * pDSoundRender;

    TRACE("(%p, %p)\n", pUnkOuter, ppv);

    *ppv = NULL;

    if (pUnkOuter)
        return CLASS_E_NOAGGREGATION;
    
    pDSoundRender = CoTaskMemAlloc(sizeof(DSoundRenderImpl));
    if (!pDSoundRender)
        return E_OUTOFMEMORY;
    ZeroMemory(pDSoundRender, sizeof(DSoundRenderImpl));

    BaseFilter_Init(&pDSoundRender->filter, &DSoundRender_Vtbl, &CLSID_DSoundRender, (DWORD_PTR)(__FILE__ ": DSoundRenderImpl.csFilter"), &BaseFuncTable);

    pDSoundRender->IBasicAudio_vtbl = &IBasicAudio_Vtbl;
    pDSoundRender->IReferenceClock_vtbl = &IReferenceClock_Vtbl;
    pDSoundRender->IAMDirectSound_vtbl = &IAMDirectSound_Vtbl;

    /* construct input pin */
    piInput.dir = PINDIR_INPUT;
    piInput.pFilter = (IBaseFilter *)pDSoundRender;
    lstrcpynW(piInput.achName, wcsInputPinName, sizeof(piInput.achName) / sizeof(piInput.achName[0]));
    hr = BaseInputPin_Construct(&DSoundRender_InputPin_Vtbl, &piInput, &input_BaseFuncTable, &input_BaseInputFuncTable, &pDSoundRender->filter.csFilter, NULL, (IPin **)&pDSoundRender->pInputPin);

    if (SUCCEEDED(hr))
    {
        hr = DirectSoundCreate8(NULL, &pDSoundRender->dsound, NULL);
        if (FAILED(hr))
            ERR("Cannot create Direct Sound object (%x)\n", hr);
        else
            IDirectSound_SetCooperativeLevel(pDSoundRender->dsound, GetDesktopWindow(), DSSCL_PRIORITY);
    }

    if (SUCCEEDED(hr))
    {
        ISeekingPassThru *passthru;
        pDSoundRender->state_change = CreateEventW(NULL, TRUE, TRUE, NULL);
        pDSoundRender->blocked = CreateEventW(NULL, TRUE, TRUE, NULL);
        hr = CoCreateInstance(&CLSID_SeekingPassThru, (IUnknown*)pDSoundRender, CLSCTX_INPROC_SERVER, &IID_IUnknown, (void**)&pDSoundRender->seekthru_unk);
        if (!pDSoundRender->state_change || !pDSoundRender->blocked || FAILED(hr))
        {
            IUnknown_Release((IUnknown *)pDSoundRender);
            return HRESULT_FROM_WIN32(GetLastError());
        }

        IUnknown_QueryInterface(pDSoundRender->seekthru_unk, &IID_ISeekingPassThru, (void**)&passthru);
        ISeekingPassThru_Init(passthru, TRUE, (IPin*)pDSoundRender->pInputPin);
        ISeekingPassThru_Release(passthru);
        *ppv = pDSoundRender;
    }
    else
    {
        if (pDSoundRender->pInputPin)
            IPin_Release((IPin*)pDSoundRender->pInputPin);
        BaseFilterImpl_Release((IBaseFilter*)pDSoundRender);
        CoTaskMemFree(pDSoundRender);
    }

    return hr;
}

static int dx_init(const char *param, int *speed, int *fragsize, int *fragnr,
                   int *channels)
{
HRESULT result;

    DEBUG(("DirectSound driver initialization: speed = %d, fragsize = %d, fragnr = %d, channels = %d\n",
           *speed, *fragsize, *fragnr, *channels));

    if (ds == NULL) {
        result = DirectSoundCreate(NULL, &ds, NULL);
        if (result != DS_OK) {
            ui_error("Cannot initialize DirectSound:\n%s", ds_error(result));
            return -1;
        }

        result = IDirectSound_SetCooperativeLevel(ds, ui_get_main_hwnd(),
                                                  DSSCL_EXCLUSIVE);
        if (result != DS_OK) {
            ui_error("Cannot set cooperative level:\n%s",
                     ds_error(result));
            return -1;
        }
    }

    memset(&capabilities, 0, sizeof(DSCAPS));
    capabilities.dwSize = sizeof(DSCAPS);

    IDirectSound_GetCaps(ds, &capabilities);
    if ((capabilities.dwFlags & DSCAPS_PRIMARY16BIT)
        || (capabilities.dwFlags & DSCAPS_SECONDARY16BIT)) {
        is16bit = 1;
    } else {
        is16bit = 0;
    }
    if (!((capabilities.dwFlags & DSCAPS_PRIMARYSTEREO)
        || (capabilities.dwFlags & DSCAPS_SECONDARYSTEREO))) {
        *channels = 1;
    }
    num_of_channels = *channels;

    DEBUG(("16bit flag: %d",is16bit));
    DEBUG(("Channels: %d",*channels));
    DEBUG(("Capabilities %08x",capabilities.dwFlags));
    DEBUG(("Secondary min Hz: %d",capabilities.dwMinSecondarySampleRate));
    DEBUG(("Secondary max Hz: %d",capabilities.dwMaxSecondarySampleRate));

    memset(&pcmwf, 0, sizeof(PCMWAVEFORMAT));
    pcmwf.wf.wFormatTag = WAVE_FORMAT_PCM;
    pcmwf.wf.nChannels = *channels;
    pcmwf.wf.nSamplesPerSec = *speed;
    pcmwf.wBitsPerSample = is16bit ? 16 : 8;
/* Hack to fix if mmsystem header is bad
    ((WORD*)&pcmwf)[7] = 16;
*/
    pcmwf.wf.nBlockAlign = (is16bit ? 2 : 1) * *channels;
    pcmwf.wf.nAvgBytesPerSec = pcmwf.wf.nSamplesPerSec * pcmwf.wf.nBlockAlign;

    memset(&desc, 0, sizeof(DSBUFFERDESC));
    desc.dwSize = sizeof(DSBUFFERDESC);
    desc.dwFlags = DSBCAPS_PRIMARYBUFFER;

    fragment_size = *fragsize; /* frames */
    buffer_size = *fragsize * *fragnr * (is16bit ? 2 : 1) * *channels; /* bytes */
    stream_buffer_size = fragment_size * *fragnr * *channels; /* nr of samples */
    buffer_offset = 0; /* bytes */
    
    result = IDirectSound_CreateSoundBuffer(ds, &desc, &pbuffer, NULL);

    if (result != DS_OK) {
        ui_error("Cannot create Primary DirectSound bufer: %s",
                 ds_error(result));
        return -1;
    }

    memset(&desc, 0, sizeof(DSBUFFERDESC));
    desc.dwSize = sizeof(DSBUFFERDESC);
    desc.dwFlags = DSBCAPS_CTRLPOSITIONNOTIFY | DSBCAPS_GETCURRENTPOSITION2
                   | DSBCAPS_CTRLFREQUENCY | DSBCAPS_CTRLPAN
                   | DSBCAPS_CTRLVOLUME | DSBCAPS_GLOBALFOCUS ;

    desc.dwBufferBytes = buffer_size;
    desc.lpwfxFormat = (LPWAVEFORMATEX)&pcmwf;

    result = IDirectSound_CreateSoundBuffer(ds, &desc, &buffer, NULL);
    if (result != DS_OK) {
        ui_error("Cannot create DirectSound buffer:\n%s", ds_error(result));
        return -1;
    }

    memset(&wfex, 0, sizeof(WAVEFORMATEX));
    wfex.wFormatTag = WAVE_FORMAT_PCM;
    wfex.nChannels = *channels;
    wfex.nSamplesPerSec = *speed;
    wfex.wBitsPerSample = is16bit ? 16 : 8;
    wfex.nBlockAlign = (is16bit ? 2 : 1) * *channels;
    wfex.nAvgBytesPerSec = wfex.nSamplesPerSec * wfex.nBlockAlign;

    result=IDirectSoundBuffer_SetFormat(pbuffer, &wfex);
    if (result != DS_OK) {
        ui_error("Cannot set Output format for primary sound buffer:\n%s",
//.........这里部分代码省略.........

static HRESULT test_frequency(LPGUID lpGuid)
{
    HRESULT rc;
    LPDIRECTSOUND dso=NULL;
    LPDIRECTSOUNDBUFFER primary=NULL,secondary=NULL;
    DSBUFFERDESC bufdesc;
    DSCAPS dscaps;
    WAVEFORMATEX wfx, wfx1;
    DWORD f, r;
    int ref;
    int rates[] = { 8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100,
                    48000, 96000 };

    /* Create the DirectSound object */
    rc=DirectSoundCreate(lpGuid,&dso,NULL);
    ok(rc==DS_OK||rc==DSERR_NODRIVER||rc==DSERR_ALLOCATED,
       "DirectSoundCreate() failed: %s\n",DXGetErrorString8(rc));
    if (rc!=DS_OK)
        return rc;

    /* Get the device capabilities */
    ZeroMemory(&dscaps, sizeof(dscaps));
    dscaps.dwSize=sizeof(dscaps);
    rc=IDirectSound_GetCaps(dso,&dscaps);
    ok(rc==DS_OK,"IDirectSound_GetCaps() failed: %s\n",DXGetErrorString8(rc));
    if (rc!=DS_OK)
        goto EXIT;

    /* We must call SetCooperativeLevel before creating primary buffer */
    /* DSOUND: Setting DirectSound cooperative level to DSSCL_PRIORITY */
    rc=IDirectSound_SetCooperativeLevel(dso,get_hwnd(),DSSCL_PRIORITY);
    ok(rc==DS_OK,"IDirectSound_SetCooperativeLevel() failed: %s\n",
       DXGetErrorString8(rc));
    if (rc!=DS_OK)
        goto EXIT;

    ZeroMemory(&bufdesc, sizeof(bufdesc));
    bufdesc.dwSize=sizeof(bufdesc);
    bufdesc.dwFlags=DSBCAPS_PRIMARYBUFFER;
    rc=IDirectSound_CreateSoundBuffer(dso,&bufdesc,&primary,NULL);
    ok(rc==DS_OK && primary!=NULL,
       "IDirectSound_CreateSoundBuffer() failed to create a primary buffer "
       "%s\n",DXGetErrorString8(rc));

    if (rc==DS_OK && primary!=NULL) {
        rc=IDirectSoundBuffer_GetFormat(primary,&wfx1,sizeof(wfx1),NULL);
        ok(rc==DS_OK,"IDirectSoundBuffer8_Getformat() failed: %s\n",
           DXGetErrorString8(rc));
        if (rc!=DS_OK)
            goto EXIT1;

        for (f=0;f<sizeof(fmts)/sizeof(fmts[0]);f++) {
        for (r=0;r<sizeof(rates)/sizeof(rates[0]);r++) {
            init_format(&wfx,WAVE_FORMAT_PCM,11025,fmts[f].bits,
                        fmts[f].channels);
            secondary=NULL;
            ZeroMemory(&bufdesc, sizeof(bufdesc));
            bufdesc.dwSize=sizeof(bufdesc);
            bufdesc.dwFlags=DSBCAPS_GETCURRENTPOSITION2|DSBCAPS_CTRLFREQUENCY;
            bufdesc.dwBufferBytes=align((wfx.nAvgBytesPerSec*rates[r]/11025)*
                                        BUFFER_LEN/1000,wfx.nBlockAlign);
            bufdesc.lpwfxFormat=&wfx;
            if (winetest_interactive) {
                trace("  Testing a secondary buffer at %ldx%dx%d "
                      "with a primary buffer at %ldx%dx%d\n",
                      wfx.nSamplesPerSec,wfx.wBitsPerSample,wfx.nChannels,
                      wfx1.nSamplesPerSec,wfx1.wBitsPerSample,wfx1.nChannels);
            }
            rc=IDirectSound_CreateSoundBuffer(dso,&bufdesc,&secondary,NULL);
            ok(rc==DS_OK && secondary!=NULL,
               "IDirectSound_CreateSoundBuffer() failed to create a secondary "
               "buffer %s\n",DXGetErrorString8(rc));

            if (rc==DS_OK && secondary!=NULL) {
                test_buffer(dso,&secondary,0,FALSE,0,FALSE,0,
                            winetest_interactive,1.0,0,NULL,0,0,TRUE,rates[r]);

                ref=IDirectSoundBuffer_Release(secondary);
                ok(ref==0,"IDirectSoundBuffer_Release() has %d references, "
                   "should have 0\n",ref);
            }
        }
        }
EXIT1:
        ref=IDirectSoundBuffer_Release(primary);
        ok(ref==0,"IDirectSoundBuffer_Release() primary has %d references, "
           "should have 0\n",ref);
    }

    /* Set the CooperativeLevel back to normal */
    /* DSOUND: Setting DirectSound cooperative level to DSSCL_NORMAL */
    rc=IDirectSound_SetCooperativeLevel(dso,get_hwnd(),DSSCL_NORMAL);
    ok(rc==DS_OK,"IDirectSound_SetCooperativeLevel() failed: %s\n",
       DXGetErrorString8(rc));

EXIT:
    ref=IDirectSound_Release(dso);
    ok(ref==0,"IDirectSound_Release() has %d references, should have 0\n",ref);
    if (ref!=0)
        return DSERR_GENERIC;
//.........这里部分代码省略.........

/**
\brief initilize direct sound
\return 0 if error, 1 if ok
*/
static int InitDirectSound(struct ao *ao)
{
    struct priv *p = ao->priv;

    DSCAPS dscaps;

    // initialize directsound
    HRESULT (WINAPI *OurDirectSoundCreate)(LPGUID, LPDIRECTSOUND *, LPUNKNOWN);
    HRESULT (WINAPI *OurDirectSoundEnumerate)(LPDSENUMCALLBACKA, LPVOID);
    p->device_index = 0;
    p->device_num = p->cfg_device;

    p->hdsound_dll = LoadLibrary("DSOUND.DLL");
    if (p->hdsound_dll == NULL) {
        MP_ERR(ao, "cannot load DSOUND.DLL\n");
        return 0;
    }
    OurDirectSoundCreate = (void *)GetProcAddress(p->hdsound_dll,
                                                  "DirectSoundCreate");
    OurDirectSoundEnumerate = (void *)GetProcAddress(p->hdsound_dll,
                                                     "DirectSoundEnumerateA");

    if (OurDirectSoundCreate == NULL || OurDirectSoundEnumerate == NULL) {
        MP_ERR(ao, "GetProcAddress FAILED\n");
        FreeLibrary(p->hdsound_dll);
        return 0;
    }

    // Enumerate all directsound p->devices
    MP_VERBOSE(ao, "Output Devices:\n");
    OurDirectSoundEnumerate(DirectSoundEnum, ao);

    // Create the direct sound object
    if (FAILED(OurDirectSoundCreate((p->device_num) ? &p->device : NULL,
                                    &p->hds, NULL)))
    {
        MP_ERR(ao, "cannot create a DirectSound device\n");
        FreeLibrary(p->hdsound_dll);
        return 0;
    }

    /* Set DirectSound Cooperative level, ie what control we want over Windows
     * sound device. In our case, DSSCL_EXCLUSIVE means that we can modify the
     * settings of the primary buffer, but also that only the sound of our
     * application will be hearable when it will have the focus.
     * !!! (this is not really working as intended yet because to set the
     * cooperative level you need the window handle of your application, and
     * I don't know of any easy way to get it. Especially since we might play
     * sound without any video, and so what window handle should we use ???
     * The hack for now is to use the Desktop window handle - it seems to be
     * working */
    if (IDirectSound_SetCooperativeLevel(p->hds, GetDesktopWindow(),
                                         DSSCL_EXCLUSIVE))
    {
        MP_ERR(ao, "cannot set direct sound cooperative level\n");
        IDirectSound_Release(p->hds);
        FreeLibrary(p->hdsound_dll);
        return 0;
    }
    MP_VERBOSE(ao, "DirectSound initialized\n");

    memset(&dscaps, 0, sizeof(DSCAPS));
    dscaps.dwSize = sizeof(DSCAPS);
    if (DS_OK == IDirectSound_GetCaps(p->hds, &dscaps)) {
        if (dscaps.dwFlags & DSCAPS_EMULDRIVER)
            MP_VERBOSE(ao, "DirectSound is emulated\n");
    } else {
        MP_VERBOSE(ao, "cannot get device capabilities\n");
    }

    return 1;
}