directsound: First shot at updating for SDL3 audio API.

This does an enormous amount of work in SDL_immdevice.c to simplify and
clean up that interface, while moving some of its responsibilities to the
higher level SDL_audio.c. I hope I saw the whole picture here, and this
wasn't foolhardy of me.

WASAPI has not been updated for these changes, or for SDL3 at all, yet. As
such, it continues to be broken for now. It will be updated soon.

This code compiles with my cross compiler, but hasn't been built with
Visual Studio, or tested in any form, so there might be obvious fixes
following along shortly.

src/audio/SDL_sysaudio.h

@@ -120,7 +120,7 @@ typedef struct SDL_AudioDriverImpl
     int (*CaptureFromDevice)(SDL_AudioDevice *device, void *buffer, int buflen);
     void (*FlushCapture)(SDL_AudioDevice *device);
     void (*CloseDevice)(SDL_AudioDevice *device);
-    void (*FreeDeviceHandle)(SDL_AudioDevice *handle); // SDL is done with this device; free the handle from SDL_AddAudioDevice()
+    void (*FreeDeviceHandle)(SDL_AudioDevice *device); // SDL is done with this device; free the handle from SDL_AddAudioDevice()
     void (*Deinitialize)(void);
 
     // Some flags to push duplicate code into the core and reduce #ifdefs.

src/audio/directsound/SDL_directsound.c

@@ -22,34 +22,34 @@
 
 #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 */
+#endif
 
 #ifndef WAVE_FORMAT_IEEE_FLOAT
 #define WAVE_FORMAT_IEEE_FLOAT 0x0003
 #endif
 
-/* For Vista+, we can enumerate DSound devices with IMMDevice */
+// For Vista+, we can enumerate DSound devices with IMMDevice
 #ifdef HAVE_MMDEVICEAPI_H
 static SDL_bool SupportsIMMDevice = SDL_FALSE;
-#endif /* HAVE_MMDEVICEAPI_H */
+#endif
 
-/* DirectX function pointers for audio */
+// 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);
+typedef HRESULT(WINAPI *fnGetDeviceID)(LPCGUID, LPGUID);
 static fnDirectSoundCreate8 pDirectSoundCreate8 = NULL;
 static fnDirectSoundEnumerateW pDirectSoundEnumerateW = NULL;
 static fnDirectSoundCaptureCreate8 pDirectSoundCaptureCreate8 = NULL;
 static fnDirectSoundCaptureEnumerateW pDirectSoundCaptureEnumerateW = NULL;
+static fnGetDeviceID pGetDeviceID = 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 } };
@@ -60,6 +60,7 @@ static void DSOUND_Unload(void)
     pDirectSoundEnumerateW = NULL;
     pDirectSoundCaptureCreate8 = NULL;
     pDirectSoundCaptureEnumerateW = NULL;
+    pGetDeviceID = NULL;
 
     if (DSoundDLL != NULL) {
         SDL_UnloadObject(DSoundDLL);
@@ -77,18 +78,19 @@ static int DSOUND_Load(void)
     if (DSoundDLL == NULL) {
         SDL_SetError("DirectSound: failed to load DSOUND.DLL");
     } else {
-/* Now make sure we have DirectX 8 or better... */
+// 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. */
+        loaded = 1; // will reset if necessary.
         DSOUNDLOAD(DirectSoundCreate8);
         DSOUNDLOAD(DirectSoundEnumerateW);
         DSOUNDLOAD(DirectSoundCaptureCreate8);
         DSOUNDLOAD(DirectSoundCaptureEnumerateW);
+        DSOUNDLOAD(GetDeviceID);
 #undef DSOUNDLOAD
 
         if (!loaded) {
@@ -150,55 +152,80 @@ static int SetDSerror(const char *function, int code)
 }
 
 static void DSOUND_FreeDeviceHandle(SDL_AudioDevice *device)
-{
-    SDL_free(device->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);
+        SDL_IMMDevice_FreeDeviceHandle(device);
+    } else
+#endif
+    {
+        SDL_free(device->handle);
     }
-#endif /* HAVE_MMDEVICEAPI_H */
-    return SDL_Unsupported();
 }
 
-static BOOL CALLBACK FindAllDevs(LPGUID guid, LPCWSTR desc, LPCWSTR module, LPVOID data)
+// FindAllDevs is presumably only used on WinXP; Vista and later can use IMMDevice for better results.
+typedef struct FindAllDevsData
 {
-    const int iscapture = (int)((size_t)data);
-    if (guid != NULL) { /* skip default device */
+    SDL_bool iscapture;
+    SDL_AudioDevice **default_device;
+    LPCGUID default_device_guid;
+} FindAllDevsData;
+
+static BOOL CALLBACK FindAllDevs(LPGUID guid, LPCWSTR desc, LPCWSTR module, LPVOID userdata)
+{
+    FindAllDevsData *data = (FindAllDevsData *) userdata;
+    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. */
+            if (cpyguid) {
+                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_AudioDevice *device = SDL_AddAudioDevice(data->iscapture, str, NULL, cpyguid);
+                if (device && data->default_device && data->default_device_guid) {
+                    if (SDL_memcmp(cpyguid, data->default_device_guid, sizeof (GUID)) == 0) {
+                        *data->default_device = device;
+                    }
+                }
+            }
+            SDL_free(str); // SDL_AddAudioDevice() makes a copy of this string.
         }
     }
-    return TRUE; /* keep enumerating. */
+    return TRUE; // keep enumerating.
 }
 
-static void DSOUND_DetectDevices(void)
+static void DSOUND_DetectDevices(SDL_AudioDevice **default_output, SDL_AudioDevice **default_capture)
 {
 #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
+        SDL_IMMDevice_EnumerateEndpoints(default_output, default_capture);
+    } else
+#endif
+    {
+        // Without IMMDevice, you can enumerate devices and figure out the default devices,
+        //  but you won't get device hotplug or default device change notifications. But this is
+        //  only for WinXP; Windows Vista and later should be using IMMDevice.
+        FindAllDevsData data;
+        GUID guid;
+
+        data.iscapture = SDL_TRUE;
+        data.default_device = default_capture;
+        data.default_device_guid = (pGetDeviceID(&DSDEVID_DefaultCapture, &guid) == DS_OK) ? &guid : NULL;
+        pDirectSoundCaptureEnumerateW(FindAllDevs, &data);
+
+        data.iscapture = SDL_FALSE;
+        data.default_device = default_output;
+        data.default_device_guid = (pGetDeviceID(&DSDEVID_DefaultPlayback, &guid) == DS_OK) ? &guid : NULL;
+        pDirectSoundEnumerateW(FindAllDevs, &data);
     }
-#endif /* HAVE_MMDEVICEAPI_H*/
+
 }
 
-static void DSOUND_WaitDevice(SDL_AudioDevice *_this)
+static void DSOUND_WaitDevice(SDL_AudioDevice *device)
 {
     DWORD status = 0;
     DWORD cursor = 0;
@@ -208,11 +235,11 @@ static void DSOUND_WaitDevice(SDL_AudioDevice *_this)
     /* 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,
+    result = IDirectSoundBuffer_GetCurrentPosition(device->hidden->mixbuf,
                                                    &junk, &cursor);
     if (result != DS_OK) {
         if (result == DSERR_BUFFERLOST) {
-            IDirectSoundBuffer_Restore(_this->hidden->mixbuf);
+            IDirectSoundBuffer_Restore(device->hidden->mixbuf);
         }
 #ifdef DEBUG_SOUND
         SetDSerror("DirectSound GetCurrentPosition", result);
@@ -220,21 +247,24 @@ static void DSOUND_WaitDevice(SDL_AudioDevice *_this)
         return;
     }
 
-    while ((cursor / _this->spec.size) == _this->hidden->lastchunk) {
-        /* FIXME: find out how much time is left and sleep that long */
+    while ((cursor / device->buffer_size) == device->hidden->lastchunk) {
+        if (SDL_AtomicGet(&device->shutdown)) {
+            return;
+        }
+
         SDL_Delay(1);
 
-        /* Try to restore a lost sound buffer */
-        IDirectSoundBuffer_GetStatus(_this->hidden->mixbuf, &status);
+        // Try to restore a lost sound buffer
+        IDirectSoundBuffer_GetStatus(device->hidden->mixbuf, &status);
         if (status & DSBSTATUS_BUFFERLOST) {
-            IDirectSoundBuffer_Restore(_this->hidden->mixbuf);
-            IDirectSoundBuffer_GetStatus(_this->hidden->mixbuf, &status);
+            IDirectSoundBuffer_Restore(device->hidden->mixbuf);
+            IDirectSoundBuffer_GetStatus(device->hidden->mixbuf, &status);
             if (status & DSBSTATUS_BUFFERLOST) {
                 break;
             }
         }
         if (!(status & DSBSTATUS_PLAYING)) {
-            result = IDirectSoundBuffer_Play(_this->hidden->mixbuf, 0, 0,
+            result = IDirectSoundBuffer_Play(device->hidden->mixbuf, 0, 0,
                                              DSBPLAY_LOOPING);
             if (result == DS_OK) {
                 continue;
@@ -245,8 +275,8 @@ static void DSOUND_WaitDevice(SDL_AudioDevice *_this)
             return;
         }
 
-        /* Find out where we are playing */
-        result = IDirectSoundBuffer_GetCurrentPosition(_this->hidden->mixbuf,
+        // Find out where we are playing
+        result = IDirectSoundBuffer_GetCurrentPosition(device->hidden->mixbuf,
                                                        &junk, &cursor);
         if (result != DS_OK) {
             SetDSerror("DirectSound GetCurrentPosition", result);
@@ -255,102 +285,100 @@ static void DSOUND_WaitDevice(SDL_AudioDevice *_this)
     }
 }
 
-static void DSOUND_PlayDevice(SDL_AudioDevice *_this)
+static void DSOUND_PlayDevice(SDL_AudioDevice *device, const Uint8 *buffer, int buflen)
 {
-    /* 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);
-    }
+    // Unlock the buffer, allowing it to play
+    SDL_assert(buflen == device->buffer_size);
+    IDirectSoundBuffer_Unlock(device->hidden->mixbuf, (LPVOID) buffer, buflen, NULL, 0);
 }
 
-static Uint8 *DSOUND_GetDeviceBuf(SDL_AudioDevice *_this)
+static Uint8 *DSOUND_GetDeviceBuf(SDL_AudioDevice *device, int *buffer_size)
 {
     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,
+    SDL_assert(*buffer_size == device->buffer_size);
+
+    // Figure out which blocks to fill next
+    device->hidden->locked_buf = NULL;
+    result = IDirectSoundBuffer_GetCurrentPosition(device->hidden->mixbuf,
                                                    &junk, &cursor);
     if (result == DSERR_BUFFERLOST) {
-        IDirectSoundBuffer_Restore(_this->hidden->mixbuf);
-        result = IDirectSoundBuffer_GetCurrentPosition(_this->hidden->mixbuf,
+        IDirectSoundBuffer_Restore(device->hidden->mixbuf);
+        result = IDirectSoundBuffer_GetCurrentPosition(device->hidden->mixbuf,
                                                        &junk, &cursor);
     }
     if (result != DS_OK) {
         SetDSerror("DirectSound GetCurrentPosition", result);
         return NULL;
     }
-    cursor /= _this->spec.size;
+    cursor /= device->buffer_size;
 #ifdef DEBUG_SOUND
-    /* Detect audio dropouts */
+    // Detect audio dropouts
     {
         DWORD spot = cursor;
-        if (spot < _this->hidden->lastchunk) {
-            spot += _this->hidden->num_buffers;
+        if (spot < device->hidden->lastchunk) {
+            spot += device->hidden->num_buffers;
         }
-        if (spot > _this->hidden->lastchunk + 1) {
+        if (spot > device->hidden->lastchunk + 1) {
             fprintf(stderr, "Audio dropout, missed %d fragments\n",
-                    (spot - (_this->hidden->lastchunk + 1)));
+                    (spot - (device->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,
+    device->hidden->lastchunk = cursor;
+    cursor = (cursor + 1) % device->hidden->num_buffers;
+    cursor *= device->buffer_size;
+
+    // Lock the audio buffer
+    DWORD rawlen = 0;
+    result = IDirectSoundBuffer_Lock(device->hidden->mixbuf, cursor,
+                                     device->buffer_size,
+                                     (LPVOID *)&device->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,
+        IDirectSoundBuffer_Restore(device->hidden->mixbuf);
+        result = IDirectSoundBuffer_Lock(device->hidden->mixbuf, cursor,
+                                         device->buffer_size,
+                                         (LPVOID *)&device->hidden->locked_buf, &rawlen, NULL,
                                          &junk, 0);
     }
     if (result != DS_OK) {
         SetDSerror("DirectSound Lock", result);
         return NULL;
     }
-    return _this->hidden->locked_buf;
+    return device->hidden->locked_buf;
 }
 
-static int DSOUND_CaptureFromDevice(SDL_AudioDevice *_this, void *buffer, int buflen)
+static void DSOUND_WaitCaptureDevice(SDL_AudioDevice *device)
 {
-    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;
-        }
-
+    struct SDL_PrivateAudioData *h = device->hidden;
+    while (!SDL_AtomicGet(&device->shutdown)) {
+        DWORD junk, cursor;
         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;
+            SDL_AudioDeviceDisconnected(device);
+            return;
+        } else if ((cursor / device->buffer_size) != h->lastchunk) {
+            return;
         }
+        SDL_Delay(1);
     }
+}
 
-    if (IDirectSoundCaptureBuffer_Lock(h->capturebuf, h->lastchunk * _this->spec.size, _this->spec.size, &ptr1, &ptr1len, &ptr2, &ptr2len, 0) != DS_OK) {
+static int DSOUND_CaptureFromDevice(SDL_AudioDevice *device, void *buffer, int buflen)
+{
+    struct SDL_PrivateAudioData *h = device->hidden;
+    DWORD ptr1len, ptr2len;
+    VOID *ptr1, *ptr2;
+
+    SDL_assert(buflen == device->buffer_size);
+
+    if (IDirectSoundCaptureBuffer_Lock(h->capturebuf, h->lastchunk * buflen, buflen, &ptr1, &ptr1len, &ptr2, &ptr2len, 0) != DS_OK) {
         return -1;
     }
 
-    SDL_assert(ptr1len == _this->spec.size);
+    SDL_assert(ptr1len == buflen);
     SDL_assert(ptr2 == NULL);
     SDL_assert(ptr2len == 0);
 
@@ -362,51 +390,54 @@ static int DSOUND_CaptureFromDevice(SDL_AudioDevice *_this, void *buffer, int bu
 
     h->lastchunk = (h->lastchunk + 1) % h->num_buffers;
 
-    return ptr1len;
+    return (int) ptr1len;
 }
 
-static void DSOUND_FlushCapture(SDL_AudioDevice *_this)
+static void DSOUND_FlushCapture(SDL_AudioDevice *device)
 {
-    struct SDL_PrivateAudioData *h = _this->hidden;
+    struct SDL_PrivateAudioData *h = device->hidden;
     DWORD junk, cursor;
     if (IDirectSoundCaptureBuffer_GetCurrentPosition(h->capturebuf, &junk, &cursor) == DS_OK) {
-        h->lastchunk = cursor / _this->spec.size;
+        h->lastchunk = cursor / device->buffer_size;
     }
 }
 
-static void DSOUND_CloseDevice(SDL_AudioDevice *_this)
+static void DSOUND_CloseDevice(SDL_AudioDevice *device)
 {
-    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);
+    if (device->hidden) {
+        if (device->hidden->mixbuf != NULL) {
+            IDirectSoundBuffer_Stop(device->hidden->mixbuf);
+            IDirectSoundBuffer_Release(device->hidden->mixbuf);
+        }
+        if (device->hidden->sound != NULL) {
+            IDirectSound_Release(device->hidden->sound);
+        }
+        if (device->hidden->capturebuf != NULL) {
+            IDirectSoundCaptureBuffer_Stop(device->hidden->capturebuf);
+            IDirectSoundCaptureBuffer_Release(device->hidden->capturebuf);
+        }
+        if (device->hidden->capture != NULL) {
+            IDirectSoundCapture_Release(device->hidden->capture);
+        }
+        SDL_free(device->hidden);
+        device->hidden = NULL;
     }
-    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)
+static int CreateSecondary(SDL_AudioDevice *device, const DWORD bufsize, WAVEFORMATEX *wfmt)
 {
-    LPDIRECTSOUND sndObj = _this->hidden->sound;
-    LPDIRECTSOUNDBUFFER *sndbuf = &_this->hidden->mixbuf;
+    LPDIRECTSOUND sndObj = device->hidden->sound;
+    LPDIRECTSOUNDBUFFER *sndbuf = &device->hidden->mixbuf;
     HRESULT result = DS_OK;
     DSBUFFERDESC format;
     LPVOID pvAudioPtr1, pvAudioPtr2;
     DWORD dwAudioBytes1, dwAudioBytes2;
 
-    /* Try to create the secondary buffer */
+    // Try to create the secondary buffer
     SDL_zero(format);
     format.dwSize = sizeof(format);
     format.dwFlags = DSBCAPS_GETCURRENTPOSITION2;
@@ -419,30 +450,29 @@ static int CreateSecondary(SDL_AudioDevice *_this, const DWORD bufsize, WAVEFORM
     }
     IDirectSoundBuffer_SetFormat(*sndbuf, wfmt);
 
-    /* Silence the initial audio buffer */
+    // 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);
+        SDL_memset(pvAudioPtr1, device->silence_value, dwAudioBytes1);
         IDirectSoundBuffer_Unlock(*sndbuf,
                                   (LPVOID)pvAudioPtr1, dwAudioBytes1,
                                   (LPVOID)pvAudioPtr2, dwAudioBytes2);
     }
 
-    /* We're ready to go */
-    return 0;
+    return 0;  // We're ready to go
 }
 
 /* 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)
+static int CreateCaptureBuffer(SDL_AudioDevice *device, const DWORD bufsize, WAVEFORMATEX *wfmt)
 {
-    LPDIRECTSOUNDCAPTURE capture = _this->hidden->capture;
-    LPDIRECTSOUNDCAPTUREBUFFER *capturebuf = &_this->hidden->capturebuf;
+    LPDIRECTSOUNDCAPTURE capture = device->hidden->capture;
+    LPDIRECTSOUNDCAPTUREBUFFER *capturebuf = &device->hidden->capturebuf;
     DSCBUFFERDESC format;
     HRESULT result;
 
@@ -464,7 +494,7 @@ static int CreateCaptureBuffer(SDL_AudioDevice *_this, const DWORD bufsize, WAVE
     }
 
 #if 0
-    /* presumably this starts at zero, but just in case... */
+    // presumably this starts at zero, but just in case...
     result = IDirectSoundCaptureBuffer_GetCurrentPosition(*capturebuf, &junk, &cursor);
     if (result != DS_OK) {
         IDirectSoundCaptureBuffer_Stop(*capturebuf);
@@ -472,42 +502,45 @@ static int CreateCaptureBuffer(SDL_AudioDevice *_this, const DWORD bufsize, WAVE
         return SetDSerror("DirectSound GetCurrentPosition", result);
     }
 
-    _this->hidden->lastchunk = cursor / _this->spec.size;
+    device->hidden->lastchunk = cursor / device->buffer_size;
 #endif
 
     return 0;
 }
 
-static int DSOUND_OpenDevice(SDL_AudioDevice *_this, const char *devname)
+static int DSOUND_OpenDevice(SDL_AudioDevice *device)
 {
-    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) {
+    // Initialize all variables that we clean on shutdown
+    device->hidden = (struct SDL_PrivateAudioData *)SDL_calloc(1, sizeof(*device->hidden));
+    if (device->hidden == NULL) {
         return SDL_OutOfMemory();
     }
-    SDL_zerop(_this->hidden);
 
-    /* Open the audio device */
-    if (iscapture) {
-        result = pDirectSoundCaptureCreate8(guid, &_this->hidden->capture, NULL);
+    // Open the audio device
+    LPGUID guid;
+#ifdef HAVE_MMDEVICEAPI_H
+    if (SupportsIMMDevice) {
+        guid = SDL_IMMDevice_GetDirectSoundGUID(device);
+    } else
+#endif
+    {
+        guid = (LPGUID) device->handle;
+    }
+
+    SDL_assert(guid != NULL);
+
+    HRESULT result;
+    if (device->iscapture) {
+        result = pDirectSoundCaptureCreate8(guid, &device->hidden->capture, NULL);
         if (result != DS_OK) {
             return SetDSerror("DirectSoundCaptureCreate8", result);
         }
     } else {
-        result = pDirectSoundCreate8(guid, &_this->hidden->sound, NULL);
+        result = pDirectSoundCreate8(guid, &device->hidden->sound, NULL);
         if (result != DS_OK) {
             return SetDSerror("DirectSoundCreate8", result);
         }
-        result = IDirectSound_SetCooperativeLevel(_this->hidden->sound,
+        result = IDirectSound_SetCooperativeLevel(device->hidden->sound,
                                                   GetDesktopWindow(),
                                                   DSSCL_NORMAL);
         if (result != DS_OK) {
@@ -515,7 +548,10 @@ static int DSOUND_OpenDevice(SDL_AudioDevice *_this, const char *devname)
         }
     }
 
-    closefmts = SDL_ClosestAudioFormats(_this->spec.format);
+    const DWORD numchunks = 8;
+    SDL_bool tried_format = SDL_FALSE;
+    SDL_AudioFormat test_format;
+    const SDL_AudioFormat *closefmts = SDL_ClosestAudioFormats(device->spec.format);
     while ((test_format = *(closefmts++)) != 0) {
         switch (test_format) {
         case SDL_AUDIO_U8:
@@ -524,69 +560,68 @@ static int DSOUND_OpenDevice(SDL_AudioDevice *_this, const char *devname)
         case SDL_AUDIO_F32:
             tried_format = SDL_TRUE;
 
-            _this->spec.format = test_format;
+            device->spec.format = test_format;
 
-            /* Update the fragment size as size in bytes */
-            SDL_CalculateAudioSpec(&_this->spec);
+            // Update the fragment size as size in bytes
+            SDL_UpdatedAudioDeviceFormat(device);
 
-            bufsize = numchunks * _this->spec.size;
+            const DWORD bufsize = numchunks * device->buffer_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) {
+                if (device->spec.channels > 2) {
                     wfmt.Format.wFormatTag = WAVE_FORMAT_EXTENSIBLE;
                     wfmt.Format.cbSize = sizeof(wfmt) - sizeof(WAVEFORMATEX);
 
-                    if (SDL_AUDIO_ISFLOAT(_this->spec.format)) {
+                    if (SDL_AUDIO_ISFLOAT(device->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);
+                    wfmt.Samples.wValidBitsPerSample = SDL_AUDIO_BITSIZE(device->spec.format);
 
-                    switch (_this->spec.channels) {
-                    case 3: /* 3.0 (or 2.1) */
+                    switch (device->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 */
+                    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) */
+                    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 */
+                    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 */
+                    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 */
+                    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)) {
+                } else if (SDL_AUDIO_ISFLOAT(device->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.wBitsPerSample = SDL_AUDIO_BITSIZE(device->spec.format);
+                wfmt.Format.nChannels = device->spec.channels;
+                wfmt.Format.nSamplesPerSec = device->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);
+                const int rc = device->iscapture ? CreateCaptureBuffer(device, bufsize, (WAVEFORMATEX *)&wfmt) : CreateSecondary(device, bufsize, (WAVEFORMATEX *)&wfmt);
                 if (rc == 0) {
-                    _this->hidden->num_buffers = numchunks;
+                    device->hidden->num_buffers = numchunks;
                     break;
                 }
             }
@@ -599,14 +634,14 @@ static int DSOUND_OpenDevice(SDL_AudioDevice *_this, const char *devname)
 
     if (!test_format) {
         if (tried_format) {
-            return -1; /* CreateSecondary() should have called SDL_SetError(). */
+            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() */
+    // Playback buffers will auto-start playing in DSOUND_WaitDevice()
 
-    return 0; /* good to go. */
+    return 0; // good to go.
 }
 
 static void DSOUND_Deinitialize(void)
@@ -616,7 +651,7 @@ static void DSOUND_Deinitialize(void)
         SDL_IMMDevice_Quit();
         SupportsIMMDevice = SDL_FALSE;
     }
-#endif /* HAVE_MMDEVICEAPI_H */
+#endif
     DSOUND_Unload();
 }
 
@@ -628,28 +663,27 @@ static SDL_bool DSOUND_Init(SDL_AudioDriverImpl *impl)
 
 #ifdef HAVE_MMDEVICEAPI_H
     SupportsIMMDevice = !(SDL_IMMDevice_Init() < 0);
-#endif /* HAVE_MMDEVICEAPI_H */
+#endif
 
-    /* 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->WaitCaptureDevice = DSOUND_WaitCaptureDevice;
     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;
 
-    return SDL_TRUE; /* this audio target is available. */
+    return SDL_TRUE;
 }
 
 AudioBootStrap DSOUND_bootstrap = {
     "directsound", "DirectSound", DSOUND_Init, SDL_FALSE
 };
 
-#endif /* SDL_AUDIO_DRIVER_DSOUND */
+#endif // SDL_AUDIO_DRIVER_DSOUND

src/audio/directsound/SDL_directsound.h

@@ -27,9 +27,10 @@
 
 #include "../SDL_sysaudio.h"
 
-/* The DirectSound objects */
+// The DirectSound objects
 struct SDL_PrivateAudioData
 {
+    // !!! FIXME: make this a union with capture/playback sections?
     LPDIRECTSOUND sound;
     LPDIRECTSOUNDBUFFER mixbuf;
     LPDIRECTSOUNDCAPTURE capture;
@@ -39,4 +40,4 @@ struct SDL_PrivateAudioData
     Uint8 *locked_buf;
 };
 
-#endif /* SDL_directsound_h_ */
+#endif // SDL_directsound_h_

src/core/windows/SDL_immdevice.c

@@ -27,6 +27,12 @@
 #include "../../audio/SDL_sysaudio.h"
 #include <objbase.h> /* For CLSIDFromString */
 
+typedef struct SDL_IMMDevice_HandleData
+{
+    LPWSTR immdevice_id;
+    GUID directsound_guid;
+} SDL_IMMDevice_HandleData;
+
 static const ERole SDL_IMMDevice_role = eConsole; /* !!! FIXME: should this be eMultimedia? Should be a hint? */
 
 /* This is global to the WASAPI target, to handle hotplug and default device lookup. */
@@ -51,9 +57,26 @@ static const GUID SDL_KSDATAFORMAT_SUBTYPE_PCM = { 0x00000001, 0x0000, 0x0010,{
 static const GUID SDL_KSDATAFORMAT_SUBTYPE_IEEE_FLOAT = { 0x00000003, 0x0000, 0x0010,{ 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71 } };
 /* *INDENT-ON* */ /* clang-format on */
 
-/* these increment as default devices change. Opened default devices pick up changes in their threads. */
-SDL_AtomicInt SDL_IMMDevice_DefaultPlaybackGeneration;
-SDL_AtomicInt SDL_IMMDevice_DefaultCaptureGeneration;
+static SDL_bool FindByDevIDCallback(SDL_AudioDevice *device, void *userdata)
+{
+    const SDL_IMMDevice_HandleData *handle = (const SDL_IMMDevice_HandleData *) device->handle;
+    return (SDL_wcscmp(handle->immdevice_id, (LPCWSTR) userdata) == 0) ? SDL_TRUE : SDL_FALSE;
+}
+
+static SDL_AudioDevice *SDL_IMMDevice_FindByDevID(LPCWSTR devid)
+{
+    return SDL_FindPhysicalAudioDeviceByCallback(FindByDevIDCallback, (void *) devid);
+}
+
+LPGUID SDL_IMMDevice_GetDirectSoundGUID(SDL_AudioDevice *device)
+{
+    return (device && device->handle) ? &(((SDL_IMMDevice_HandleData *) device->handle)->directsound_guid) : NULL;
+}
+
+LPCWSTR SDL_IMMDevice_GetDevID(SDL_AudioDevice *device)
+{
+    return (device && device->handle) ? ((const SDL_IMMDevice_HandleData *) device->handle)->immdevice_id : NULL;
+}
 
 static void GetMMDeviceInfo(IMMDevice *device, char **utf8dev, WAVEFORMATEXTENSIBLE *fmt, GUID *guid)
 {
@@ -82,94 +105,54 @@ static void GetMMDeviceInfo(IMMDevice *device, char **utf8dev, WAVEFORMATEXTENSI
     }
 }
 
-/* This is a list of device id strings we have inflight, so we have consistent pointers to the same device. */
-typedef struct DevIdList
-{
-    LPWSTR str;
-    LPGUID guid;
-    struct DevIdList *next;
-} DevIdList;
-
-static DevIdList *deviceid_list = NULL;
-
-static void SDL_IMMDevice_Remove(const SDL_bool iscapture, LPCWSTR devid, SDL_bool useguid)
+void SDL_IMMDevice_FreeDeviceHandle(SDL_AudioDevice *device)
 {
-    DevIdList *i;
-    DevIdList *next;
-    DevIdList *prev = NULL;
-    for (i = deviceid_list; i; i = next) {
-        next = i->next;
-        if (SDL_wcscmp(i->str, devid) == 0) {
-            if (prev) {
-                prev->next = next;
-            } else {
-                deviceid_list = next;
-            }
-            SDL_RemoveAudioDevice(iscapture, useguid ? ((void *)i->guid) : ((void *)i->str));
-            SDL_free(i->str);
-            SDL_free(i);
-        } else {
-            prev = i;
-        }
+    if (device && device->handle) {
+        SDL_IMMDevice_HandleData *handle = (SDL_IMMDevice_HandleData *) device->handle;
+        SDL_free(handle->immdevice_id);
+        SDL_free(handle);
+        device->handle = NULL;
     }
 }
 
-static void SDL_IMMDevice_Add(const SDL_bool iscapture, const char *devname, WAVEFORMATEXTENSIBLE *fmt, LPCWSTR devid, GUID *dsoundguid, SDL_bool useguid)
+static SDL_AudioDevice *SDL_IMMDevice_Add(const SDL_bool iscapture, const char *devname, WAVEFORMATEXTENSIBLE *fmt, LPCWSTR devid, GUID *dsoundguid)
 {
-    DevIdList *devidlist;
-    SDL_AudioSpec spec;
-    LPWSTR devidcopy;
-    LPGUID cpyguid;
-    LPVOID driverdata;
-
     /* You can have multiple endpoints on a device that are mutually exclusive ("Speakers" vs "Line Out" or whatever).
        In a perfect world, things that are unplugged won't be in this collection. The only gotcha is probably for
        phones and tablets, where you might have an internal speaker and a headphone jack and expect both to be
        available and switch automatically. (!!! FIXME...?) */
 
-    /* see if we already have this one. */
-    for (devidlist = deviceid_list; devidlist; devidlist = devidlist->next) {
-        if (SDL_wcscmp(devidlist->str, devid) == 0) {
-            return; /* we already have this. */
-        }
+    if (!devname) {
+        return NULL;
     }
 
-    devidlist = (DevIdList *)SDL_malloc(sizeof(*devidlist));
-    if (devidlist == NULL) {
-        return; /* oh well. */
-    }
+    // see if we already have this one first.
+    SDL_AudioDevice *device = SDL_IMMDevice_FindByDevID(devid);
+    if (!device) {
+        // handle is freed by SDL_IMMDevice_FreeDeviceHandle!
+        SDL_IMMDevice_HandleData *handle = SDL_malloc(sizeof(SDL_IMMDevice_HandleData));
+        if (!handle) {
+            SDL_OutOfMemory();
+            return NULL;
+        }
+        handle->immdevice_id = SDL_wcsdup(devid);
+        if (!handle->immdevice_id) {
+            SDL_OutOfMemory();
+            SDL_free(handle);
+            return NULL;
+        }
+        SDL_memcpy(&handle->directsound_guid, dsoundguid, sizeof(GUID));
 
-    devidcopy = SDL_wcsdup(devid);
-    if (!devidcopy) {
-        SDL_free(devidlist);
-        return; /* oh well. */
-    }
+        SDL_AudioSpec spec;
+        SDL_zero(spec);
+        spec.channels = (Uint8)fmt->Format.nChannels;
+        spec.freq = fmt->Format.nSamplesPerSec;
+        spec.format = WaveFormatToSDLFormat((WAVEFORMATEX *)fmt);
 
-    if (useguid) {
-        /* This is freed by DSOUND_FreeDeviceData! */
-        cpyguid = (LPGUID)SDL_malloc(sizeof(GUID));
-        if (!cpyguid) {
-            SDL_free(devidlist);
-            SDL_free(devidcopy);
-            return; /* oh well. */
-        }
-        SDL_memcpy(cpyguid, dsoundguid, sizeof(GUID));
-        driverdata = cpyguid;
-    } else {
-        cpyguid = NULL;
-        driverdata = devidcopy;
+        device = SDL_AddAudioDevice(iscapture, devname, &spec, handle);
     }
 
-    devidlist->str = devidcopy;
-    devidlist->guid = cpyguid;
-    devidlist->next = deviceid_list;
-    deviceid_list = devidlist;
-
-    SDL_zero(spec);
-    spec.channels = (Uint8)fmt->Format.nChannels;
-    spec.freq = fmt->Format.nSamplesPerSec;
-    spec.format = WaveFormatToSDLFormat((WAVEFORMATEX *)fmt);
-    SDL_AddAudioDevice(iscapture, devname, &spec, driverdata);
+    return device;
 }
 
 /* We need a COM subclass of IMMNotificationClient for hotplug support, which is
@@ -184,11 +167,11 @@ typedef struct SDLMMNotificationClient
     SDL_bool useguid;
 } SDLMMNotificationClient;
 
-static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_QueryInterface(IMMNotificationClient *this, REFIID iid, void **ppv)
+static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_QueryInterface(IMMNotificationClient *client, REFIID iid, void **ppv)
 {
     if ((WIN_IsEqualIID(iid, &IID_IUnknown)) || (WIN_IsEqualIID(iid, &SDL_IID_IMMNotificationClient))) {
-        *ppv = this;
-        this->lpVtbl->AddRef(this);
+        *ppv = client;
+        client->lpVtbl->AddRef(client);
         return S_OK;
     }
 
@@ -196,55 +179,34 @@ static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_QueryInterface(IMMNotif
     return E_NOINTERFACE;
 }
 
-static ULONG STDMETHODCALLTYPE SDLMMNotificationClient_AddRef(IMMNotificationClient *ithis)
+static ULONG STDMETHODCALLTYPE SDLMMNotificationClient_AddRef(IMMNotificationClient *iclient)
 {
-    SDLMMNotificationClient *this = (SDLMMNotificationClient *)ithis;
-    return (ULONG)(SDL_AtomicIncRef(&this->refcount) + 1);
+    SDLMMNotificationClient *client = (SDLMMNotificationClient *)iclient;
+    return (ULONG)(SDL_AtomicIncRef(&client->refcount) + 1);
 }
 
-static ULONG STDMETHODCALLTYPE SDLMMNotificationClient_Release(IMMNotificationClient *ithis)
+static ULONG STDMETHODCALLTYPE SDLMMNotificationClient_Release(IMMNotificationClient *iclient)
 {
-    /* this is a static object; we don't ever free it. */
-    SDLMMNotificationClient *this = (SDLMMNotificationClient *)ithis;
-    const ULONG retval = SDL_AtomicDecRef(&this->refcount);
+    /* client is a static object; we don't ever free it. */
+    SDLMMNotificationClient *client = (SDLMMNotificationClient *)iclient;
+    const ULONG retval = SDL_AtomicDecRef(&client->refcount);
     if (retval == 0) {
-        SDL_AtomicSet(&this->refcount, 0); /* uhh... */
+        SDL_AtomicSet(&client->refcount, 0); /* uhh... */
         return 0;
     }
     return retval - 1;
 }
 
-/* These are the entry points called when WASAPI device endpoints change. */
-static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDefaultDeviceChanged(IMMNotificationClient *ithis, EDataFlow flow, ERole role, LPCWSTR pwstrDeviceId)
+// These are the entry points called when WASAPI device endpoints change.
+static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDefaultDeviceChanged(IMMNotificationClient *iclient, EDataFlow flow, ERole role, LPCWSTR pwstrDeviceId)
 {
-    if (role != SDL_IMMDevice_role) {
-        return S_OK; /* ignore it. */
+    if (role == SDL_IMMDevice_role) {
+        SDL_DefaultAudioDeviceChanged(SDL_IMMDevice_FindByDevID(pwstrDeviceId));
     }
-
-    /* Increment the "generation," so opened devices will pick this up in their threads. */
-    switch (flow) {
-    case eRender:
-        SDL_AtomicAdd(&SDL_IMMDevice_DefaultPlaybackGeneration, 1);
-        break;
-
-    case eCapture:
-        SDL_AtomicAdd(&SDL_IMMDevice_DefaultCaptureGeneration, 1);
-        break;
-
-    case eAll:
-        SDL_AtomicAdd(&SDL_IMMDevice_DefaultPlaybackGeneration, 1);
-        SDL_AtomicAdd(&SDL_IMMDevice_DefaultCaptureGeneration, 1);
-        break;
-
-    default:
-        SDL_assert(!"uhoh, unexpected OnDefaultDeviceChange flow!");
-        break;
-    }
-
     return S_OK;
 }
 
-static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceAdded(IMMNotificationClient *ithis, LPCWSTR pwstrDeviceId)
+static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceAdded(IMMNotificationClient *iclient, LPCWSTR pwstrDeviceId)
 {
     /* we ignore this; devices added here then progress to ACTIVE, if appropriate, in
        OnDeviceStateChange, making that a better place to deal with device adds. More
@@ -254,13 +216,12 @@ static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceAdded(IMMNotifi
     return S_OK;
 }
 
-static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceRemoved(IMMNotificationClient *ithis, LPCWSTR pwstrDeviceId)
+static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceRemoved(IMMNotificationClient *iclient, LPCWSTR pwstrDeviceId)
 {
-    /* See notes in OnDeviceAdded handler about why we ignore this. */
-    return S_OK;
+    return S_OK;  // See notes in OnDeviceAdded handler about why we ignore this.
 }
 
-static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceStateChanged(IMMNotificationClient *ithis, LPCWSTR pwstrDeviceId, DWORD dwNewState)
+static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceStateChanged(IMMNotificationClient *iclient, LPCWSTR pwstrDeviceId, DWORD dwNewState)
 {
     IMMDevice *device = NULL;
 
@@ -270,18 +231,17 @@ static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceStateChanged(IM
             EDataFlow flow;
             if (SUCCEEDED(IMMEndpoint_GetDataFlow(endpoint, &flow))) {
                 const SDL_bool iscapture = (flow == eCapture);
-                const SDLMMNotificationClient *client = (SDLMMNotificationClient *)ithis;
                 if (dwNewState == DEVICE_STATE_ACTIVE) {
                     char *utf8dev;
                     WAVEFORMATEXTENSIBLE fmt;
                     GUID dsoundguid;
                     GetMMDeviceInfo(device, &utf8dev, &fmt, &dsoundguid);
                     if (utf8dev) {
-                        SDL_IMMDevice_Add(iscapture, utf8dev, &fmt, pwstrDeviceId, &dsoundguid, client->useguid);
+                        SDL_IMMDevice_Add(iscapture, utf8dev, &fmt, pwstrDeviceId, &dsoundguid);
                         SDL_free(utf8dev);
                     }
                 } else {
-                    SDL_IMMDevice_Remove(iscapture, pwstrDeviceId, client->useguid);
+                    SDL_AudioDeviceDisconnected(SDL_IMMDevice_FindByDevID(pwstrDeviceId));
                 }
             }
             IMMEndpoint_Release(endpoint);
@@ -292,9 +252,9 @@ static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceStateChanged(IM
     return S_OK;
 }
 
-static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnPropertyValueChanged(IMMNotificationClient *this, LPCWSTR pwstrDeviceId, const PROPERTYKEY key)
+static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnPropertyValueChanged(IMMNotificationClient *client, LPCWSTR pwstrDeviceId, const PROPERTYKEY key)
 {
-    return S_OK; /* we don't care about these. */
+    return S_OK; // we don't care about these.
 }
 
 static const IMMNotificationClientVtbl notification_client_vtbl = {
@@ -314,31 +274,25 @@ int SDL_IMMDevice_Init(void)
 {
     HRESULT ret;
 
-    SDL_AtomicSet(&SDL_IMMDevice_DefaultPlaybackGeneration, 1);
-    SDL_AtomicSet(&SDL_IMMDevice_DefaultCaptureGeneration, 1);
-
     /* just skip the discussion with COM here. */
     if (!WIN_IsWindowsVistaOrGreater()) {
-        return SDL_SetError("WASAPI support requires Windows Vista or later");
+        return SDL_SetError("IMMDevice support requires Windows Vista or later");
     }
 
     if (FAILED(WIN_CoInitialize())) {
-        return SDL_SetError("WASAPI: CoInitialize() failed");
+        return SDL_SetError("IMMDevice: CoInitialize() failed");
     }
 
     ret = CoCreateInstance(&SDL_CLSID_MMDeviceEnumerator, NULL, CLSCTX_INPROC_SERVER, &SDL_IID_IMMDeviceEnumerator, (LPVOID *)&enumerator);
     if (FAILED(ret)) {
         WIN_CoUninitialize();
-        return WIN_SetErrorFromHRESULT("WASAPI CoCreateInstance(MMDeviceEnumerator)", ret);
+        return WIN_SetErrorFromHRESULT("IMMDevice CoCreateInstance(MMDeviceEnumerator)", ret);
     }
     return 0;
 }
 
 void SDL_IMMDevice_Quit(void)
 {
-    DevIdList *devidlist;
-    DevIdList *next;
-
     if (enumerator) {
         IMMDeviceEnumerator_UnregisterEndpointNotificationCallback(enumerator, (IMMNotificationClient *)&notification_client);
         IMMDeviceEnumerator_Release(enumerator);
@@ -346,178 +300,101 @@ void SDL_IMMDevice_Quit(void)
     }
 
     WIN_CoUninitialize();
-
-    for (devidlist = deviceid_list; devidlist; devidlist = next) {
-        next = devidlist->next;
-        SDL_free(devidlist->str);
-        SDL_free(devidlist);
-    }
-    deviceid_list = NULL;
 }
 
-int SDL_IMMDevice_Get(LPCWSTR devid, IMMDevice **device, SDL_bool iscapture)
+int SDL_IMMDevice_Get(SDL_AudioDevice *device, IMMDevice **immdevice, SDL_bool iscapture)
 {
     const Uint64 timeout = SDL_GetTicks() + 8000;  /* intel's audio drivers can fail for up to EIGHT SECONDS after a device is connected or we wake from sleep. */
-    HRESULT ret;
 
     SDL_assert(device != NULL);
+    SDL_assert(immdevice != NULL);
 
-    while (SDL_TRUE) {
-        if (devid == NULL) {
-            const EDataFlow dataflow = iscapture ? eCapture : eRender;
-            ret = IMMDeviceEnumerator_GetDefaultAudioEndpoint(enumerator, dataflow, SDL_IMMDevice_role, device);
-        } else {
-            ret = IMMDeviceEnumerator_GetDevice(enumerator, devid, device);
-        }
+    LPCWSTR devid = SDL_IMMDevice_GetDevID(device);
+    SDL_assert(devid != NULL);
 
-        if (SUCCEEDED(ret)) {
-            break;
-        }
-
-        if (ret == E_NOTFOUND) {
-            const Uint64 now = SDL_GetTicks();
-            if (timeout > now) {
-                const Uint64 ticksleft = timeout - now;
-                SDL_Delay((Uint32)SDL_min(ticksleft, 300));   /* wait awhile and try again. */
-                continue;
-            }
+    HRESULT ret;
+    while ((ret = IMMDeviceEnumerator_GetDevice(enumerator, devid, immdevice)) == E_NOTFOUND) {
+        const Uint64 now = SDL_GetTicks();
+        if (timeout > now) {
+            const Uint64 ticksleft = timeout - now;
+            SDL_Delay((Uint32)SDL_min(ticksleft, 300));   /* wait awhile and try again. */
+            continue;
         }
-
-        return WIN_SetErrorFromHRESULT("WASAPI can't find requested audio endpoint", ret);
-    }
-    return 0;
-}
-
-typedef struct
-{
-    LPWSTR devid;
-    char *devname;
-    WAVEFORMATEXTENSIBLE fmt;
-    GUID dsoundguid;
-} EndpointItem;
-
-static int SDLCALL sort_endpoints(const void *_a, const void *_b)
-{
-    LPWSTR a = ((const EndpointItem *)_a)->devid;
-    LPWSTR b = ((const EndpointItem *)_b)->devid;
-    if (!a && !b) {
-        return 0;
-    } else if (!a && b) {
-        return -1;
-    } else if (a && !b) {
-        return 1;
+        break;
     }
 
-    while (SDL_TRUE) {
-        if (*a < *b) {
-            return -1;
-        } else if (*a > *b) {
-            return 1;
-        } else if (*a == 0) {
-            break;
-        }
-        a++;
-        b++;
-    }
+    return SUCCEEDED(ret) ? 0 : WIN_SetErrorFromHRESULT("WASAPI can't find requested audio endpoint", ret);
 
-    return 0;
 }
 
-static void EnumerateEndpointsForFlow(const SDL_bool iscapture)
+static void EnumerateEndpointsForFlow(const SDL_bool iscapture, SDL_AudioDevice **default_device)
 {
-    IMMDeviceCollection *collection = NULL;
-    EndpointItem *items;
-    UINT i, total;
-
     /* Note that WASAPI separates "adapter devices" from "audio endpoint devices"
        ...one adapter device ("SoundBlaster Pro") might have multiple endpoint devices ("Speakers", "Line-Out"). */
 
+    IMMDeviceCollection *collection = NULL;
     if (FAILED(IMMDeviceEnumerator_EnumAudioEndpoints(enumerator, iscapture ? eCapture : eRender, DEVICE_STATE_ACTIVE, &collection))) {
         return;
     }
 
+    UINT total = 0;
     if (FAILED(IMMDeviceCollection_GetCount(collection, &total))) {
         IMMDeviceCollection_Release(collection);
         return;
     }
 
-    items = (EndpointItem *)SDL_calloc(total, sizeof(EndpointItem));
-    if (items == NULL) {
-        return; /* oh well. */
-    }
-
-    for (i = 0; i < total; i++) {
-        EndpointItem *item = items + i;
-        IMMDevice *device = NULL;
-        if (SUCCEEDED(IMMDeviceCollection_Item(collection, i, &device))) {
-            if (SUCCEEDED(IMMDevice_GetId(device, &item->devid))) {
-                GetMMDeviceInfo(device, &item->devname, &item->fmt, &item->dsoundguid);
+    LPWSTR default_devid = NULL;
+    if (default_device) {
+        IMMDevice *default_immdevice = NULL;
+        const EDataFlow dataflow = iscapture ? eCapture : eRender;
+        if (SUCCEEDED(IMMDeviceEnumerator_GetDefaultAudioEndpoint(enumerator, dataflow, SDL_IMMDevice_role, &default_immdevice))) {
+            LPWSTR devid = NULL;
+            if (SUCCEEDED(IMMDevice_GetId(default_immdevice, &devid))) {
+                default_devid = SDL_wcsdup(devid);  // if this fails, oh well.
+                CoTaskMemFree(devid);
             }
-            IMMDevice_Release(device);
+            IMMDevice_Release(default_immdevice);
         }
     }
 
-    /* sort the list of devices by their guid so list is consistent between runs */
-    SDL_qsort(items, total, sizeof(*items), sort_endpoints);
-
-    /* Send the sorted list on to the SDL's higher level. */
-    for (i = 0; i < total; i++) {
-        EndpointItem *item = items + i;
-        if ((item->devid) && (item->devname)) {
-            SDL_IMMDevice_Add(iscapture, item->devname, &item->fmt, item->devid, &item->dsoundguid, notification_client.useguid);
+    for (UINT i = 0; i < total; i++) {
+        IMMDevice *immdevice = NULL;
+        if (SUCCEEDED(IMMDeviceCollection_Item(collection, i, &immdevice))) {
+            LPWSTR devid = NULL;
+            if (SUCCEEDED(IMMDevice_GetId(immdevice, &devid))) {
+                char *devname = NULL;
+                WAVEFORMATEXTENSIBLE fmt;
+                GUID dsoundguid;
+                SDL_zero(fmt);
+                SDL_zero(dsoundguid);
+                GetMMDeviceInfo(immdevice, &devname, &fmt, &dsoundguid);
+                if (devname) {
+                    SDL_AudioDevice *sdldevice = SDL_IMMDevice_Add(iscapture, devname, &fmt, devid, &dsoundguid);
+                    if (default_device && default_devid && SDL_wcscmp(default_devid, devid)) {
+                        *default_device = sdldevice;
+                    }
+                    SDL_free(devname);
+                }
+                CoTaskMemFree(devid);
+            }
+            IMMDevice_Release(immdevice);
         }
-        SDL_free(item->devname);
-        CoTaskMemFree(item->devid);
     }
 
-    SDL_free(items);
+    SDL_free(default_devid);
+
     IMMDeviceCollection_Release(collection);
 }
 
-void SDL_IMMDevice_EnumerateEndpoints(SDL_bool useguid)
+void SDL_IMMDevice_EnumerateEndpoints(SDL_AudioDevice **default_output, SDL_AudioDevice **default_capture)
 {
-    notification_client.useguid = useguid;
-
-    EnumerateEndpointsForFlow(SDL_FALSE); /* playback */
-    EnumerateEndpointsForFlow(SDL_TRUE);  /* capture */
+    EnumerateEndpointsForFlow(SDL_FALSE, default_output); /* playback */
+    EnumerateEndpointsForFlow(SDL_TRUE, default_capture);  /* capture */
 
     /* if this fails, we just won't get hotplug events. Carry on anyhow. */
     IMMDeviceEnumerator_RegisterEndpointNotificationCallback(enumerator, (IMMNotificationClient *)&notification_client);
 }
 
-int SDL_IMMDevice_GetDefaultAudioInfo(char **name, SDL_AudioSpec *spec, int iscapture)
-{
-    WAVEFORMATEXTENSIBLE fmt;
-    IMMDevice *device = NULL;
-    char *filler;
-    GUID morefiller;
-    const EDataFlow dataflow = iscapture ? eCapture : eRender;
-    HRESULT ret = IMMDeviceEnumerator_GetDefaultAudioEndpoint(enumerator, dataflow, SDL_IMMDevice_role, &device);
-
-    if (FAILED(ret)) {
-        SDL_assert(device == NULL);
-        return WIN_SetErrorFromHRESULT("WASAPI can't find default audio endpoint", ret);
-    }
-
-    if (name == NULL) {
-        name = &filler;
-    }
-
-    SDL_zero(fmt);
-    GetMMDeviceInfo(device, name, &fmt, &morefiller);
-    IMMDevice_Release(device);
-
-    if (name == &filler) {
-        SDL_free(filler);
-    }
-
-    SDL_zerop(spec);
-    spec->channels = (Uint8)fmt.Format.nChannels;
-    spec->freq = fmt.Format.nSamplesPerSec;
-    spec->format = WaveFormatToSDLFormat((WAVEFORMATEX *)&fmt);
-    return 0;
-}
-
 SDL_AudioFormat WaveFormatToSDLFormat(WAVEFORMATEX *waveformat)
 {
     if ((waveformat->wFormatTag == WAVE_FORMAT_IEEE_FLOAT) && (waveformat->wBitsPerSample == 32)) {

src/core/windows/SDL_immdevice.h

@@ -26,16 +26,15 @@
 #include <mmdeviceapi.h>
 #include <mmreg.h>
 
+typedef struct SDL_AudioDevice SDL_AudioDevice; // this is defined in src/audio/SDL_sysaudio.h
+
 int SDL_IMMDevice_Init(void);
 void SDL_IMMDevice_Quit(void);
-int SDL_IMMDevice_Get(LPCWSTR devid, IMMDevice **device, SDL_bool iscapture);
-void SDL_IMMDevice_EnumerateEndpoints(SDL_bool useguid);
-int SDL_IMMDevice_GetDefaultAudioInfo(char **name, SDL_AudioSpec *spec, int iscapture);
-
+int SDL_IMMDevice_Get(SDL_AudioDevice *device, IMMDevice **immdevice, SDL_bool iscapture);
+void SDL_IMMDevice_EnumerateEndpoints(SDL_AudioDevice **default_output, SDL_AudioDevice **default_capture);
+LPGUID SDL_IMMDevice_GetDirectSoundGUID(SDL_AudioDevice *device);
+LPCWSTR SDL_IMMDevice_GetDevID(SDL_AudioDevice *device);
+void SDL_IMMDevice_FreeDeviceHandle(SDL_AudioDevice *device);
 SDL_AudioFormat WaveFormatToSDLFormat(WAVEFORMATEX *waveformat);
 
-/* these increment as default devices change. Opened default devices pick up changes in their threads. */
-extern SDL_AtomicInt SDL_IMMDevice_DefaultPlaybackGeneration;
-extern SDL_AtomicInt SDL_IMMDevice_DefaultCaptureGeneration;
-
 #endif /* SDL_IMMDEVICE_H */