wasapi: Force enumerated audio devices to report themselves as float32 format.

This is what they'll end up being when used through WASAPI in shared mode,
regardless of what the hardware actually expects.

Reference Issue #12914.

(cherry picked from commit a81cf566f4efae124ef0a9c84f8b299899740e0d)

src/audio/directsound/SDL_directsound.c

@@ -206,7 +206,7 @@ static void DSOUND_DetectDevices(SDL_AudioDevice **default_playback, SDL_AudioDe
 {
 #ifdef HAVE_MMDEVICEAPI_H
     if (SupportsIMMDevice) {
-        SDL_IMMDevice_EnumerateEndpoints(default_playback, default_recording);
+        SDL_IMMDevice_EnumerateEndpoints(default_playback, default_recording, SDL_AUDIO_UNKNOWN);
     } else
 #endif
     {

src/audio/wasapi/SDL_wasapi.c

@@ -337,7 +337,7 @@ typedef struct
 static bool mgmtthrtask_DetectDevices(void *userdata)
 {
     mgmtthrtask_DetectDevicesData *data = (mgmtthrtask_DetectDevicesData *)userdata;
-    SDL_IMMDevice_EnumerateEndpoints(data->default_playback, data->default_recording);
+    SDL_IMMDevice_EnumerateEndpoints(data->default_playback, data->default_recording, SDL_AUDIO_F32);
     return true;
 }
 

src/core/windows/SDL_immdevice.c

@@ -120,7 +120,7 @@ void SDL_IMMDevice_FreeDeviceHandle(SDL_AudioDevice *device)
     }
 }
 
-static SDL_AudioDevice *SDL_IMMDevice_Add(const bool recording, const char *devname, WAVEFORMATEXTENSIBLE *fmt, LPCWSTR devid, GUID *dsoundguid)
+static SDL_AudioDevice *SDL_IMMDevice_Add(const bool recording, const char *devname, WAVEFORMATEXTENSIBLE *fmt, LPCWSTR devid, GUID *dsoundguid, SDL_AudioFormat force_format)
 {
     /* 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
@@ -162,7 +162,7 @@ static SDL_AudioDevice *SDL_IMMDevice_Add(const bool recording, const char *devn
         SDL_zero(spec);
         spec.channels = (Uint8)fmt->Format.nChannels;
         spec.freq = fmt->Format.nSamplesPerSec;
-        spec.format = SDL_WaveFormatExToSDLFormat((WAVEFORMATEX *)fmt);
+        spec.format = (force_format != SDL_AUDIO_UNKNOWN) ? force_format : SDL_WaveFormatExToSDLFormat((WAVEFORMATEX *)fmt);
 
         device = SDL_AddAudioDevice(recording, devname, &spec, handle);
         if (!device) {
@@ -183,6 +183,7 @@ typedef struct SDLMMNotificationClient
 {
     const IMMNotificationClientVtbl *lpVtbl;
     SDL_AtomicInt refcount;
+    SDL_AudioFormat force_format;
 } SDLMMNotificationClient;
 
 static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_QueryInterface(IMMNotificationClient *client, REFIID iid, void **ppv)
@@ -241,6 +242,7 @@ static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceRemoved(IMMNoti
 
 static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceStateChanged(IMMNotificationClient *iclient, LPCWSTR pwstrDeviceId, DWORD dwNewState)
 {
+    SDLMMNotificationClient *client = (SDLMMNotificationClient *)iclient;
     IMMDevice *device = NULL;
 
     if (SUCCEEDED(IMMDeviceEnumerator_GetDevice(enumerator, pwstrDeviceId, &device))) {
@@ -255,7 +257,7 @@ static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceStateChanged(IM
                     GUID dsoundguid;
                     GetMMDeviceInfo(device, &utf8dev, &fmt, &dsoundguid);
                     if (utf8dev) {
-                        SDL_IMMDevice_Add(recording, utf8dev, &fmt, pwstrDeviceId, &dsoundguid);
+                        SDL_IMMDevice_Add(recording, utf8dev, &fmt, pwstrDeviceId, &dsoundguid, client->force_format);
                         SDL_free(utf8dev);
                     }
                 } else {
@@ -286,7 +288,7 @@ static const IMMNotificationClientVtbl notification_client_vtbl = {
     SDLMMNotificationClient_OnPropertyValueChanged
 };
 
-static SDLMMNotificationClient notification_client = { &notification_client_vtbl, { 1 } };
+static SDLMMNotificationClient notification_client = { &notification_client_vtbl, { 1 }, SDL_AUDIO_UNKNOWN };
 
 bool SDL_IMMDevice_Init(const SDL_IMMDevice_callbacks *callbacks)
 {
@@ -363,7 +365,7 @@ bool SDL_IMMDevice_Get(SDL_AudioDevice *device, IMMDevice **immdevice, bool reco
     return true;
 }
 
-static void EnumerateEndpointsForFlow(const bool recording, SDL_AudioDevice **default_device)
+static void EnumerateEndpointsForFlow(const bool recording, SDL_AudioDevice **default_device, SDL_AudioFormat force_format)
 {
     /* Note that WASAPI separates "adapter devices" from "audio endpoint devices"
        ...one adapter device ("SoundBlaster Pro") might have multiple endpoint devices ("Speakers", "Line-Out"). */
@@ -405,7 +407,7 @@ static void EnumerateEndpointsForFlow(const bool recording, SDL_AudioDevice **de
                 SDL_zero(dsoundguid);
                 GetMMDeviceInfo(immdevice, &devname, &fmt, &dsoundguid);
                 if (devname) {
-                    SDL_AudioDevice *sdldevice = SDL_IMMDevice_Add(recording, devname, &fmt, devid, &dsoundguid);
+                    SDL_AudioDevice *sdldevice = SDL_IMMDevice_Add(recording, devname, &fmt, devid, &dsoundguid, force_format);
                     if (default_device && default_devid && SDL_wcscmp(default_devid, devid) == 0) {
                         *default_device = sdldevice;
                     }
@@ -422,10 +424,12 @@ static void EnumerateEndpointsForFlow(const bool recording, SDL_AudioDevice **de
     IMMDeviceCollection_Release(collection);
 }
 
-void SDL_IMMDevice_EnumerateEndpoints(SDL_AudioDevice **default_playback, SDL_AudioDevice **default_recording)
+void SDL_IMMDevice_EnumerateEndpoints(SDL_AudioDevice **default_playback, SDL_AudioDevice **default_recording, SDL_AudioFormat force_format)
 {
-    EnumerateEndpointsForFlow(false, default_playback);
-    EnumerateEndpointsForFlow(true, default_recording);
+    EnumerateEndpointsForFlow(false, default_playback, force_format);
+    EnumerateEndpointsForFlow(true, default_recording, force_format);
+
+    notification_client.force_format = force_format;
 
     // if this fails, we just won't get hotplug events. Carry on anyhow.
     IMMDeviceEnumerator_RegisterEndpointNotificationCallback(enumerator, (IMMNotificationClient *)&notification_client);

src/core/windows/SDL_immdevice.h

@@ -37,7 +37,7 @@ typedef struct SDL_IMMDevice_callbacks
 bool SDL_IMMDevice_Init(const SDL_IMMDevice_callbacks *callbacks);
 void SDL_IMMDevice_Quit(void);
 bool SDL_IMMDevice_Get(struct SDL_AudioDevice *device, IMMDevice **immdevice, bool recording);
-void SDL_IMMDevice_EnumerateEndpoints(struct SDL_AudioDevice **default_playback, struct SDL_AudioDevice **default_recording);
+void SDL_IMMDevice_EnumerateEndpoints(struct SDL_AudioDevice **default_playback, struct SDL_AudioDevice **default_recording, SDL_AudioFormat force_format);
 LPGUID SDL_IMMDevice_GetDirectSoundGUID(struct SDL_AudioDevice *device);
 LPCWSTR SDL_IMMDevice_GetDevID(struct SDL_AudioDevice *device);
 void SDL_IMMDevice_FreeDeviceHandle(struct SDL_AudioDevice *device);