tomato-testing/src/audio/directsound/SDL_directsound.c

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2023 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_internal.h"

#ifdef SDL_AUDIO_DRIVER_DSOUND

/* Allow access to a raw mixing buffer */

#include "../SDL_audio_c.h"
#include "SDL_directsound.h"
#include <mmreg.h>
#ifdef HAVE_MMDEVICEAPI_H
#include "../../core/windows/SDL_immdevice.h"
#endif /* HAVE_MMDEVICEAPI_H */

#ifndef WAVE_FORMAT_IEEE_FLOAT
#define WAVE_FORMAT_IEEE_FLOAT 0x0003
#endif

/* For Vista+, we can enumerate DSound devices with IMMDevice */
#ifdef HAVE_MMDEVICEAPI_H
static SDL_bool SupportsIMMDevice = SDL_FALSE;
#endif /* HAVE_MMDEVICEAPI_H */

/* DirectX function pointers for audio */
static void *DSoundDLL = NULL;
typedef HRESULT(WINAPI *fnDirectSoundCreate8)(LPGUID, LPDIRECTSOUND *, LPUNKNOWN);
typedef HRESULT(WINAPI *fnDirectSoundEnumerateW)(LPDSENUMCALLBACKW, LPVOID);
typedef HRESULT(WINAPI *fnDirectSoundCaptureCreate8)(LPCGUID, LPDIRECTSOUNDCAPTURE8 *, LPUNKNOWN);
typedef HRESULT(WINAPI *fnDirectSoundCaptureEnumerateW)(LPDSENUMCALLBACKW, LPVOID);
static fnDirectSoundCreate8 pDirectSoundCreate8 = NULL;
static fnDirectSoundEnumerateW pDirectSoundEnumerateW = NULL;
static fnDirectSoundCaptureCreate8 pDirectSoundCaptureCreate8 = NULL;
static fnDirectSoundCaptureEnumerateW pDirectSoundCaptureEnumerateW = NULL;

static const GUID SDL_KSDATAFORMAT_SUBTYPE_PCM = { 0x00000001, 0x0000, 0x0010, { 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 } };
static const GUID SDL_KSDATAFORMAT_SUBTYPE_IEEE_FLOAT = { 0x00000003, 0x0000, 0x0010, { 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 } };

static void DSOUND_Unload(void)
{
    pDirectSoundCreate8 = NULL;
    pDirectSoundEnumerateW = NULL;
    pDirectSoundCaptureCreate8 = NULL;
    pDirectSoundCaptureEnumerateW = NULL;

    if (DSoundDLL != NULL) {
        SDL_UnloadObject(DSoundDLL);
        DSoundDLL = NULL;
    }
}

static int DSOUND_Load(void)
{
    int loaded = 0;

    DSOUND_Unload();

    DSoundDLL = SDL_LoadObject("DSOUND.DLL");
    if (DSoundDLL == NULL) {
        SDL_SetError("DirectSound: failed to load DSOUND.DLL");
    } else {
/* Now make sure we have DirectX 8 or better... */
#define DSOUNDLOAD(f)                                  \
    {                                                  \
        p##f = (fn##f)SDL_LoadFunction(DSoundDLL, #f); \
        if (!p##f)                                     \
            loaded = 0;                                \
    }
        loaded = 1; /* will reset if necessary. */
        DSOUNDLOAD(DirectSoundCreate8);
        DSOUNDLOAD(DirectSoundEnumerateW);
        DSOUNDLOAD(DirectSoundCaptureCreate8);
        DSOUNDLOAD(DirectSoundCaptureEnumerateW);
#undef DSOUNDLOAD

        if (!loaded) {
            SDL_SetError("DirectSound: System doesn't appear to have DX8.");
        }
    }

    if (!loaded) {
        DSOUND_Unload();
    }

    return loaded;
}

static int SetDSerror(const char *function, int code)
{
    const char *error;

    switch (code) {
    case E_NOINTERFACE:
        error = "Unsupported interface -- Is DirectX 8.0 or later installed?";
        break;
    case DSERR_ALLOCATED:
        error = "Audio device in use";
        break;
    case DSERR_BADFORMAT:
        error = "Unsupported audio format";
        break;
    case DSERR_BUFFERLOST:
        error = "Mixing buffer was lost";
        break;
    case DSERR_CONTROLUNAVAIL:
        error = "Control requested is not available";
        break;
    case DSERR_INVALIDCALL:
        error = "Invalid call for the current state";
        break;
    case DSERR_INVALIDPARAM:
        error = "Invalid parameter";
        break;
    case DSERR_NODRIVER:
        error = "No audio device found";
        break;
    case DSERR_OUTOFMEMORY:
        error = "Out of memory";
        break;
    case DSERR_PRIOLEVELNEEDED:
        error = "Caller doesn't have priority";
        break;
    case DSERR_UNSUPPORTED:
        error = "Function not supported";
        break;
    default:
        error = "Unknown DirectSound error";
        break;
    }

    return SDL_SetError("%s: %s (0x%x)", function, error, code);
}

static void DSOUND_FreeDeviceHandle(void *handle)
{
    SDL_free(handle);
}

static int DSOUND_GetDefaultAudioInfo(char **name, SDL_AudioSpec *spec, int iscapture)
{
#ifdef HAVE_MMDEVICEAPI_H
    if (SupportsIMMDevice) {
        return SDL_IMMDevice_GetDefaultAudioInfo(name, spec, iscapture);
    }
#endif /* HAVE_MMDEVICEAPI_H */
    return SDL_Unsupported();
}

static BOOL CALLBACK FindAllDevs(LPGUID guid, LPCWSTR desc, LPCWSTR module, LPVOID data)
{
    const int iscapture = (int)((size_t)data);
    if (guid != NULL) { /* skip default device */
        char *str = WIN_LookupAudioDeviceName(desc, guid);
        if (str != NULL) {
            LPGUID cpyguid = (LPGUID)SDL_malloc(sizeof(GUID));
            SDL_memcpy(cpyguid, guid, sizeof(GUID));

            /* Note that spec is NULL, because we are required to connect to the
             * device before getting the channel mask and output format, making
             * this information inaccessible at enumeration time
             */
            SDL_AddAudioDevice(iscapture, str, NULL, cpyguid);
            SDL_free(str); /* addfn() makes a copy of this string. */
        }
    }
    return TRUE; /* keep enumerating. */
}

static void DSOUND_DetectDevices(void)
{
#ifdef HAVE_MMDEVICEAPI_H
    if (SupportsIMMDevice) {
        SDL_IMMDevice_EnumerateEndpoints(SDL_TRUE);
    } else {
#endif /* HAVE_MMDEVICEAPI_H */
        pDirectSoundCaptureEnumerateW(FindAllDevs, (void *)((size_t)1));
        pDirectSoundEnumerateW(FindAllDevs, (void *)((size_t)0));
#ifdef HAVE_MMDEVICEAPI_H
    }
#endif /* HAVE_MMDEVICEAPI_H*/
}

static void DSOUND_WaitDevice(SDL_AudioDevice *_this)
{
    DWORD status = 0;
    DWORD cursor = 0;
    DWORD junk = 0;
    HRESULT result = DS_OK;

    /* Semi-busy wait, since we have no way of getting play notification
       on a primary mixing buffer located in hardware (DirectX 5.0)
     */
    result = IDirectSoundBuffer_GetCurrentPosition(_this->hidden->mixbuf,
                                                   &junk, &cursor);
    if (result != DS_OK) {
        if (result == DSERR_BUFFERLOST) {
            IDirectSoundBuffer_Restore(_this->hidden->mixbuf);
        }
#ifdef DEBUG_SOUND
        SetDSerror("DirectSound GetCurrentPosition", result);
#endif
        return;
    }

    while ((cursor / _this->spec.size) == _this->hidden->lastchunk) {
        /* FIXME: find out how much time is left and sleep that long */
        SDL_Delay(1);

        /* Try to restore a lost sound buffer */
        IDirectSoundBuffer_GetStatus(_this->hidden->mixbuf, &status);
        if (status & DSBSTATUS_BUFFERLOST) {
            IDirectSoundBuffer_Restore(_this->hidden->mixbuf);
            IDirectSoundBuffer_GetStatus(_this->hidden->mixbuf, &status);
            if (status & DSBSTATUS_BUFFERLOST) {
                break;
            }
        }
        if (!(status & DSBSTATUS_PLAYING)) {
            result = IDirectSoundBuffer_Play(_this->hidden->mixbuf, 0, 0,
                                             DSBPLAY_LOOPING);
            if (result == DS_OK) {
                continue;
            }
#ifdef DEBUG_SOUND
            SetDSerror("DirectSound Play", result);
#endif
            return;
        }

        /* Find out where we are playing */
        result = IDirectSoundBuffer_GetCurrentPosition(_this->hidden->mixbuf,
                                                       &junk, &cursor);
        if (result != DS_OK) {
            SetDSerror("DirectSound GetCurrentPosition", result);
            return;
        }
    }
}

static void DSOUND_PlayDevice(SDL_AudioDevice *_this)
{
    /* Unlock the buffer, allowing it to play */
    if (_this->hidden->locked_buf) {
        IDirectSoundBuffer_Unlock(_this->hidden->mixbuf,
                                  _this->hidden->locked_buf,
                                  _this->spec.size, NULL, 0);
    }
}

static Uint8 *DSOUND_GetDeviceBuf(SDL_AudioDevice *_this)
{
    DWORD cursor = 0;
    DWORD junk = 0;
    HRESULT result = DS_OK;
    DWORD rawlen = 0;

    /* Figure out which blocks to fill next */
    _this->hidden->locked_buf = NULL;
    result = IDirectSoundBuffer_GetCurrentPosition(_this->hidden->mixbuf,
                                                   &junk, &cursor);
    if (result == DSERR_BUFFERLOST) {
        IDirectSoundBuffer_Restore(_this->hidden->mixbuf);
        result = IDirectSoundBuffer_GetCurrentPosition(_this->hidden->mixbuf,
                                                       &junk, &cursor);
    }
    if (result != DS_OK) {
        SetDSerror("DirectSound GetCurrentPosition", result);
        return NULL;
    }
    cursor /= _this->spec.size;
#ifdef DEBUG_SOUND
    /* Detect audio dropouts */
    {
        DWORD spot = cursor;
        if (spot < _this->hidden->lastchunk) {
            spot += _this->hidden->num_buffers;
        }
        if (spot > _this->hidden->lastchunk + 1) {
            fprintf(stderr, "Audio dropout, missed %d fragments\n",
                    (spot - (_this->hidden->lastchunk + 1)));
        }
    }
#endif
    _this->hidden->lastchunk = cursor;
    cursor = (cursor + 1) % _this->hidden->num_buffers;
    cursor *= _this->spec.size;

    /* Lock the audio buffer */
    result = IDirectSoundBuffer_Lock(_this->hidden->mixbuf, cursor,
                                     _this->spec.size,
                                     (LPVOID *)&_this->hidden->locked_buf,
                                     &rawlen, NULL, &junk, 0);
    if (result == DSERR_BUFFERLOST) {
        IDirectSoundBuffer_Restore(_this->hidden->mixbuf);
        result = IDirectSoundBuffer_Lock(_this->hidden->mixbuf, cursor,
                                         _this->spec.size,
                                         (LPVOID *)&_this->hidden->locked_buf, &rawlen, NULL,
                                         &junk, 0);
    }
    if (result != DS_OK) {
        SetDSerror("DirectSound Lock", result);
        return NULL;
    }
    return _this->hidden->locked_buf;
}

static int DSOUND_CaptureFromDevice(SDL_AudioDevice *_this, void *buffer, int buflen)
{
    struct SDL_PrivateAudioData *h = _this->hidden;
    DWORD junk, cursor, ptr1len, ptr2len;
    VOID *ptr1, *ptr2;

    SDL_assert((Uint32)buflen == _this->spec.size);

    while (SDL_TRUE) {
        if (SDL_AtomicGet(&_this->shutdown)) { /* in case the buffer froze... */
            SDL_memset(buffer, _this->spec.silence, buflen);
            return buflen;
        }

        if (IDirectSoundCaptureBuffer_GetCurrentPosition(h->capturebuf, &junk, &cursor) != DS_OK) {
            return -1;
        }
        if ((cursor / _this->spec.size) == h->lastchunk) {
            SDL_Delay(1); /* FIXME: find out how much time is left and sleep that long */
        } else {
            break;
        }
    }

    if (IDirectSoundCaptureBuffer_Lock(h->capturebuf, h->lastchunk * _this->spec.size, _this->spec.size, &ptr1, &ptr1len, &ptr2, &ptr2len, 0) != DS_OK) {
        return -1;
    }

    SDL_assert(ptr1len == _this->spec.size);
    SDL_assert(ptr2 == NULL);
    SDL_assert(ptr2len == 0);

    SDL_memcpy(buffer, ptr1, ptr1len);

    if (IDirectSoundCaptureBuffer_Unlock(h->capturebuf, ptr1, ptr1len, ptr2, ptr2len) != DS_OK) {
        return -1;
    }

    h->lastchunk = (h->lastchunk + 1) % h->num_buffers;

    return ptr1len;
}

static void DSOUND_FlushCapture(SDL_AudioDevice *_this)
{
    struct SDL_PrivateAudioData *h = _this->hidden;
    DWORD junk, cursor;
    if (IDirectSoundCaptureBuffer_GetCurrentPosition(h->capturebuf, &junk, &cursor) == DS_OK) {
        h->lastchunk = cursor / _this->spec.size;
    }
}

static void DSOUND_CloseDevice(SDL_AudioDevice *_this)
{
    if (_this->hidden->mixbuf != NULL) {
        IDirectSoundBuffer_Stop(_this->hidden->mixbuf);
        IDirectSoundBuffer_Release(_this->hidden->mixbuf);
    }
    if (_this->hidden->sound != NULL) {
        IDirectSound_Release(_this->hidden->sound);
    }
    if (_this->hidden->capturebuf != NULL) {
        IDirectSoundCaptureBuffer_Stop(_this->hidden->capturebuf);
        IDirectSoundCaptureBuffer_Release(_this->hidden->capturebuf);
    }
    if (_this->hidden->capture != NULL) {
        IDirectSoundCapture_Release(_this->hidden->capture);
    }
    SDL_free(_this->hidden);
}

/* This function tries to create a secondary audio buffer, and returns the
   number of audio chunks available in the created buffer. This is for
   playback devices, not capture.
*/
static int CreateSecondary(SDL_AudioDevice *_this, const DWORD bufsize, WAVEFORMATEX *wfmt)
{
    LPDIRECTSOUND sndObj = _this->hidden->sound;
    LPDIRECTSOUNDBUFFER *sndbuf = &_this->hidden->mixbuf;
    HRESULT result = DS_OK;
    DSBUFFERDESC format;
    LPVOID pvAudioPtr1, pvAudioPtr2;
    DWORD dwAudioBytes1, dwAudioBytes2;

    /* Try to create the secondary buffer */
    SDL_zero(format);
    format.dwSize = sizeof(format);
    format.dwFlags = DSBCAPS_GETCURRENTPOSITION2;
    format.dwFlags |= DSBCAPS_GLOBALFOCUS;
    format.dwBufferBytes = bufsize;
    format.lpwfxFormat = wfmt;
    result = IDirectSound_CreateSoundBuffer(sndObj, &format, sndbuf, NULL);
    if (result != DS_OK) {
        return SetDSerror("DirectSound CreateSoundBuffer", result);
    }
    IDirectSoundBuffer_SetFormat(*sndbuf, wfmt);

    /* Silence the initial audio buffer */
    result = IDirectSoundBuffer_Lock(*sndbuf, 0, format.dwBufferBytes,
                                     (LPVOID *)&pvAudioPtr1, &dwAudioBytes1,
                                     (LPVOID *)&pvAudioPtr2, &dwAudioBytes2,
                                     DSBLOCK_ENTIREBUFFER);
    if (result == DS_OK) {
        SDL_memset(pvAudioPtr1, _this->spec.silence, dwAudioBytes1);
        IDirectSoundBuffer_Unlock(*sndbuf,
                                  (LPVOID)pvAudioPtr1, dwAudioBytes1,
                                  (LPVOID)pvAudioPtr2, dwAudioBytes2);
    }

    /* We're ready to go */
    return 0;
}

/* This function tries to create a capture buffer, and returns the
   number of audio chunks available in the created buffer. This is for
   capture devices, not playback.
*/
static int CreateCaptureBuffer(SDL_AudioDevice *_this, const DWORD bufsize, WAVEFORMATEX *wfmt)
{
    LPDIRECTSOUNDCAPTURE capture = _this->hidden->capture;
    LPDIRECTSOUNDCAPTUREBUFFER *capturebuf = &_this->hidden->capturebuf;
    DSCBUFFERDESC format;
    HRESULT result;

    SDL_zero(format);
    format.dwSize = sizeof(format);
    format.dwFlags = DSCBCAPS_WAVEMAPPED;
    format.dwBufferBytes = bufsize;
    format.lpwfxFormat = wfmt;

    result = IDirectSoundCapture_CreateCaptureBuffer(capture, &format, capturebuf, NULL);
    if (result != DS_OK) {
        return SetDSerror("DirectSound CreateCaptureBuffer", result);
    }

    result = IDirectSoundCaptureBuffer_Start(*capturebuf, DSCBSTART_LOOPING);
    if (result != DS_OK) {
        IDirectSoundCaptureBuffer_Release(*capturebuf);
        return SetDSerror("DirectSound Start", result);
    }

#if 0
    /* presumably this starts at zero, but just in case... */
    result = IDirectSoundCaptureBuffer_GetCurrentPosition(*capturebuf, &junk, &cursor);
    if (result != DS_OK) {
        IDirectSoundCaptureBuffer_Stop(*capturebuf);
        IDirectSoundCaptureBuffer_Release(*capturebuf);
        return SetDSerror("DirectSound GetCurrentPosition", result);
    }

    _this->hidden->lastchunk = cursor / _this->spec.size;
#endif

    return 0;
}

static int DSOUND_OpenDevice(SDL_AudioDevice *_this, const char *devname)
{
    const DWORD numchunks = 8;
    HRESULT result;
    SDL_bool tried_format = SDL_FALSE;
    SDL_bool iscapture = _this->iscapture;
    SDL_AudioFormat test_format;
    const SDL_AudioFormat *closefmts;
    LPGUID guid = (LPGUID)_this->handle;
    DWORD bufsize;

    /* Initialize all variables that we clean on shutdown */
    _this->hidden = (struct SDL_PrivateAudioData *)SDL_malloc(sizeof(*_this->hidden));
    if (_this->hidden == NULL) {
        return SDL_OutOfMemory();
    }
    SDL_zerop(_this->hidden);

    /* Open the audio device */
    if (iscapture) {
        result = pDirectSoundCaptureCreate8(guid, &_this->hidden->capture, NULL);
        if (result != DS_OK) {
            return SetDSerror("DirectSoundCaptureCreate8", result);
        }
    } else {
        result = pDirectSoundCreate8(guid, &_this->hidden->sound, NULL);
        if (result != DS_OK) {
            return SetDSerror("DirectSoundCreate8", result);
        }
        result = IDirectSound_SetCooperativeLevel(_this->hidden->sound,
                                                  GetDesktopWindow(),
                                                  DSSCL_NORMAL);
        if (result != DS_OK) {
            return SetDSerror("DirectSound SetCooperativeLevel", result);
        }
    }

    closefmts = SDL_ClosestAudioFormats(_this->spec.format);
    while ((test_format = *(closefmts++)) != 0) {
        switch (test_format) {
        case SDL_AUDIO_U8:
        case SDL_AUDIO_S16:
        case SDL_AUDIO_S32:
        case SDL_AUDIO_F32:
            tried_format = SDL_TRUE;

            _this->spec.format = test_format;

            /* Update the fragment size as size in bytes */
            SDL_CalculateAudioSpec(&_this->spec);

            bufsize = numchunks * _this->spec.size;
            if ((bufsize < DSBSIZE_MIN) || (bufsize > DSBSIZE_MAX)) {
                SDL_SetError("Sound buffer size must be between %d and %d",
                             (int)((DSBSIZE_MIN < numchunks) ? 1 : DSBSIZE_MIN / numchunks),
                             (int)(DSBSIZE_MAX / numchunks));
            } else {
                int rc;
                WAVEFORMATEXTENSIBLE wfmt;
                SDL_zero(wfmt);
                if (_this->spec.channels > 2) {
                    wfmt.Format.wFormatTag = WAVE_FORMAT_EXTENSIBLE;
                    wfmt.Format.cbSize = sizeof(wfmt) - sizeof(WAVEFORMATEX);

                    if (SDL_AUDIO_ISFLOAT(_this->spec.format)) {
                        SDL_memcpy(&wfmt.SubFormat, &SDL_KSDATAFORMAT_SUBTYPE_IEEE_FLOAT, sizeof(GUID));
                    } else {
                        SDL_memcpy(&wfmt.SubFormat, &SDL_KSDATAFORMAT_SUBTYPE_PCM, sizeof(GUID));
                    }
                    wfmt.Samples.wValidBitsPerSample = SDL_AUDIO_BITSIZE(_this->spec.format);

                    switch (_this->spec.channels) {
                    case 3: /* 3.0 (or 2.1) */
                        wfmt.dwChannelMask = SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_FRONT_CENTER;
                        break;
                    case 4: /* 4.0 */
                        wfmt.dwChannelMask = SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_BACK_LEFT | SPEAKER_BACK_RIGHT;
                        break;
                    case 5: /* 5.0 (or 4.1) */
                        wfmt.dwChannelMask = SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_FRONT_CENTER | SPEAKER_BACK_LEFT | SPEAKER_BACK_RIGHT;
                        break;
                    case 6: /* 5.1 */
                        wfmt.dwChannelMask = SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_FRONT_CENTER | SPEAKER_LOW_FREQUENCY | SPEAKER_BACK_LEFT | SPEAKER_BACK_RIGHT;
                        break;
                    case 7: /* 6.1 */
                        wfmt.dwChannelMask = SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_FRONT_CENTER | SPEAKER_LOW_FREQUENCY | SPEAKER_BACK_LEFT | SPEAKER_BACK_RIGHT | SPEAKER_BACK_CENTER;
                        break;
                    case 8: /* 7.1 */
                        wfmt.dwChannelMask = SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_FRONT_CENTER | SPEAKER_LOW_FREQUENCY | SPEAKER_BACK_LEFT | SPEAKER_BACK_RIGHT | SPEAKER_SIDE_LEFT | SPEAKER_SIDE_RIGHT;
                        break;
                    default:
                        SDL_assert(0 && "Unsupported channel count!");
                        break;
                    }
                } else if (SDL_AUDIO_ISFLOAT(_this->spec.format)) {
                    wfmt.Format.wFormatTag = WAVE_FORMAT_IEEE_FLOAT;
                } else {
                    wfmt.Format.wFormatTag = WAVE_FORMAT_PCM;
                }

                wfmt.Format.wBitsPerSample = SDL_AUDIO_BITSIZE(_this->spec.format);
                wfmt.Format.nChannels = _this->spec.channels;
                wfmt.Format.nSamplesPerSec = _this->spec.freq;
                wfmt.Format.nBlockAlign = wfmt.Format.nChannels * (wfmt.Format.wBitsPerSample / 8);
                wfmt.Format.nAvgBytesPerSec = wfmt.Format.nSamplesPerSec * wfmt.Format.nBlockAlign;

                rc = iscapture ? CreateCaptureBuffer(_this, bufsize, (WAVEFORMATEX *)&wfmt) : CreateSecondary(_this, bufsize, (WAVEFORMATEX *)&wfmt);
                if (rc == 0) {
                    _this->hidden->num_buffers = numchunks;
                    break;
                }
            }
            continue;
        default:
            continue;
        }
        break;
    }

    if (!test_format) {
        if (tried_format) {
            return -1; /* CreateSecondary() should have called SDL_SetError(). */
        }
        return SDL_SetError("%s: Unsupported audio format", "directsound");
    }

    /* Playback buffers will auto-start playing in DSOUND_WaitDevice() */

    return 0; /* good to go. */
}

static void DSOUND_Deinitialize(void)
{
#ifdef HAVE_MMDEVICEAPI_H
    if (SupportsIMMDevice) {
        SDL_IMMDevice_Quit();
        SupportsIMMDevice = SDL_FALSE;
    }
#endif /* HAVE_MMDEVICEAPI_H */
    DSOUND_Unload();
}

static SDL_bool DSOUND_Init(SDL_AudioDriverImpl *impl)
{
    if (!DSOUND_Load()) {
        return SDL_FALSE;
    }

#ifdef HAVE_MMDEVICEAPI_H
    SupportsIMMDevice = !(SDL_IMMDevice_Init() < 0);
#endif /* HAVE_MMDEVICEAPI_H */

    /* Set the function pointers */
    impl->DetectDevices = DSOUND_DetectDevices;
    impl->OpenDevice = DSOUND_OpenDevice;
    impl->PlayDevice = DSOUND_PlayDevice;
    impl->WaitDevice = DSOUND_WaitDevice;
    impl->GetDeviceBuf = DSOUND_GetDeviceBuf;
    impl->CaptureFromDevice = DSOUND_CaptureFromDevice;
    impl->FlushCapture = DSOUND_FlushCapture;
    impl->CloseDevice = DSOUND_CloseDevice;
    impl->FreeDeviceHandle = DSOUND_FreeDeviceHandle;
    impl->Deinitialize = DSOUND_Deinitialize;
    impl->GetDefaultAudioInfo = DSOUND_GetDefaultAudioInfo;

    impl->HasCaptureSupport = SDL_TRUE;
    impl->SupportsNonPow2Samples = SDL_TRUE;

    return SDL_TRUE; /* this audio target is available. */
}

AudioBootStrap DSOUND_bootstrap = {
    "directsound", "DirectSound", DSOUND_Init, SDL_FALSE
};

#endif /* SDL_AUDIO_DRIVER_DSOUND */