Atlas - SDL_wasapi_win32.c
Home / ext / SDL2 / src / audio / wasapi
Lines: 1 | Size: 14774 bytes
[Download] [Show on GitHub] [Search similar files] [Raw] [Raw (proxy)] 
[FILE BEGIN]
1/*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2018 Sam Lantinga <[email protected]>
4
5  This software is provided 'as-is', without any express or implied
6  warranty.  In no event will the authors be held liable for any damages
7  arising from the use of this software.
8
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12
13  1. The origin of this software must not be misrepresented; you must not
14     claim that you wrote the original software. If you use this software
15     in a product, an acknowledgment in the product documentation would be
16     appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18     misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20*/
21
22#include "../../SDL_internal.h"
23
24/* This is code that Windows uses to talk to WASAPI-related system APIs.
25   This is for non-WinRT desktop apps. The C++/CX implementation of these
26   functions, exclusive to WinRT, are in SDL_wasapi_winrt.cpp.
27   The code in SDL_wasapi.c is used by both standard Windows and WinRT builds
28   to deal with audio and calls into these functions. */
29
30#if SDL_AUDIO_DRIVER_WASAPI && !defined(__WINRT__)
31
32#include "../../core/windows/SDL_windows.h"
33#include "SDL_audio.h"
34#include "SDL_timer.h"
35#include "../SDL_audio_c.h"
36#include "../SDL_sysaudio.h"
37#include "SDL_assert.h"
38#include "SDL_log.h"
39
40#define COBJMACROS
41#include <mmdeviceapi.h>
42#include <audioclient.h>
43
44#include "SDL_wasapi.h"
45
46static const ERole SDL_WASAPI_role = eConsole;  /* !!! FIXME: should this be eMultimedia? Should be a hint? */
47
48/* This is global to the WASAPI target, to handle hotplug and default device lookup. */
49static IMMDeviceEnumerator *enumerator = NULL;
50
51/* PropVariantInit() is an inline function/macro in PropIdl.h that calls the C runtime's memset() directly. Use ours instead, to avoid dependency. */
52#ifdef PropVariantInit
53#undef PropVariantInit
54#endif
55#define PropVariantInit(p) SDL_zerop(p)
56
57/* handle to Avrt.dll--Vista and later!--for flagging the callback thread as "Pro Audio" (low latency). */
58static HMODULE libavrt = NULL;
59typedef HANDLE(WINAPI *pfnAvSetMmThreadCharacteristicsW)(LPWSTR, LPDWORD);
60typedef BOOL(WINAPI *pfnAvRevertMmThreadCharacteristics)(HANDLE);
61static pfnAvSetMmThreadCharacteristicsW pAvSetMmThreadCharacteristicsW = NULL;
62static pfnAvRevertMmThreadCharacteristics pAvRevertMmThreadCharacteristics = NULL;
63
64/* Some GUIDs we need to know without linking to libraries that aren't available before Vista. */
65static const CLSID SDL_CLSID_MMDeviceEnumerator = { 0xbcde0395, 0xe52f, 0x467c,{ 0x8e, 0x3d, 0xc4, 0x57, 0x92, 0x91, 0x69, 0x2e } };
66static const IID SDL_IID_IMMDeviceEnumerator = { 0xa95664d2, 0x9614, 0x4f35,{ 0xa7, 0x46, 0xde, 0x8d, 0xb6, 0x36, 0x17, 0xe6 } };
67static const IID SDL_IID_IMMNotificationClient = { 0x7991eec9, 0x7e89, 0x4d85,{ 0x83, 0x90, 0x6c, 0x70, 0x3c, 0xec, 0x60, 0xc0 } };
68static const IID SDL_IID_IMMEndpoint = { 0x1be09788, 0x6894, 0x4089,{ 0x85, 0x86, 0x9a, 0x2a, 0x6c, 0x26, 0x5a, 0xc5 } };
69static const IID SDL_IID_IAudioClient = { 0x1cb9ad4c, 0xdbfa, 0x4c32,{ 0xb1, 0x78, 0xc2, 0xf5, 0x68, 0xa7, 0x03, 0xb2 } };
70static const PROPERTYKEY SDL_PKEY_Device_FriendlyName = { { 0xa45c254e, 0xdf1c, 0x4efd,{ 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0, } }, 14 };
71
72
73static char *
74GetWasapiDeviceName(IMMDevice *device)
75{
76    /* PKEY_Device_FriendlyName gives you "Speakers (SoundBlaster Pro)" which drives me nuts. I'd rather it be
77       "SoundBlaster Pro (Speakers)" but I guess that's developers vs users. Windows uses the FriendlyName in
78       its own UIs, like Volume Control, etc. */
79    char *utf8dev = NULL;
80    IPropertyStore *props = NULL;
81    if (SUCCEEDED(IMMDevice_OpenPropertyStore(device, STGM_READ, &props))) {
82        PROPVARIANT var;
83        PropVariantInit(&var);
84        if (SUCCEEDED(IPropertyStore_GetValue(props, &SDL_PKEY_Device_FriendlyName, &var))) {
85            utf8dev = WIN_StringToUTF8(var.pwszVal);
86        }
87        PropVariantClear(&var);
88        IPropertyStore_Release(props);
89    }
90    return utf8dev;
91}
92
93
94/* We need a COM subclass of IMMNotificationClient for hotplug support, which is
95   easy in C++, but we have to tapdance more to make work in C.
96   Thanks to this page for coaching on how to make this work:
97     https://www.codeproject.com/Articles/13601/COM-in-plain-C */
98
99typedef struct SDLMMNotificationClient
100{
101    const IMMNotificationClientVtbl *lpVtbl;
102    SDL_atomic_t refcount;
103} SDLMMNotificationClient;
104
105static HRESULT STDMETHODCALLTYPE
106SDLMMNotificationClient_QueryInterface(IMMNotificationClient *this, REFIID iid, void **ppv)
107{
108    if ((WIN_IsEqualIID(iid, &IID_IUnknown)) || (WIN_IsEqualIID(iid, &SDL_IID_IMMNotificationClient)))
109    {
110        *ppv = this;
111        this->lpVtbl->AddRef(this);
112        return S_OK;
113    }
114
115    *ppv = NULL;
116    return E_NOINTERFACE;
117}
118
119static ULONG STDMETHODCALLTYPE
120SDLMMNotificationClient_AddRef(IMMNotificationClient *ithis)
121{
122    SDLMMNotificationClient *this = (SDLMMNotificationClient *) ithis;
123    return (ULONG) (SDL_AtomicIncRef(&this->refcount) + 1);
124}
125
126static ULONG STDMETHODCALLTYPE
127SDLMMNotificationClient_Release(IMMNotificationClient *ithis)
128{
129    /* this is a static object; we don't ever free it. */
130    SDLMMNotificationClient *this = (SDLMMNotificationClient *) ithis;
131    const ULONG retval = SDL_AtomicDecRef(&this->refcount);
132    if (retval == 0) {
133        SDL_AtomicSet(&this->refcount, 0);  /* uhh... */
134        return 0;
135    }
136    return retval - 1;
137}
138
139/* These are the entry points called when WASAPI device endpoints change. */
140static HRESULT STDMETHODCALLTYPE
141SDLMMNotificationClient_OnDefaultDeviceChanged(IMMNotificationClient *ithis, EDataFlow flow, ERole role, LPCWSTR pwstrDeviceId)
142{
143    if (role != SDL_WASAPI_role) {
144        return S_OK;  /* ignore it. */
145    }
146
147    /* Increment the "generation," so opened devices will pick this up in their threads. */
148    switch (flow) {
149        case eRender:
150            SDL_AtomicAdd(&WASAPI_DefaultPlaybackGeneration, 1);
151            break;
152
153        case eCapture:
154            SDL_AtomicAdd(&WASAPI_DefaultCaptureGeneration, 1);
155            break;
156
157        case eAll:
158            SDL_AtomicAdd(&WASAPI_DefaultPlaybackGeneration, 1);
159            SDL_AtomicAdd(&WASAPI_DefaultCaptureGeneration, 1);
160            break;
161
162        default:
163            SDL_assert(!"uhoh, unexpected OnDefaultDeviceChange flow!");
164            break;
165    }
166
167    return S_OK;
168}
169
170static HRESULT STDMETHODCALLTYPE
171SDLMMNotificationClient_OnDeviceAdded(IMMNotificationClient *ithis, LPCWSTR pwstrDeviceId)
172{
173    /* we ignore this; devices added here then progress to ACTIVE, if appropriate, in 
174       OnDeviceStateChange, making that a better place to deal with device adds. More 
175       importantly: the first time you plug in a USB audio device, this callback will 
176       fire, but when you unplug it, it isn't removed (it's state changes to NOTPRESENT).
177       Plugging it back in won't fire this callback again. */
178    return S_OK;
179}
180
181static HRESULT STDMETHODCALLTYPE
182SDLMMNotificationClient_OnDeviceRemoved(IMMNotificationClient *ithis, LPCWSTR pwstrDeviceId)
183{
184    /* See notes in OnDeviceAdded handler about why we ignore this. */
185    return S_OK;
186}
187
188static HRESULT STDMETHODCALLTYPE
189SDLMMNotificationClient_OnDeviceStateChanged(IMMNotificationClient *ithis, LPCWSTR pwstrDeviceId, DWORD dwNewState)
190{
191    IMMDevice *device = NULL;
192
193    if (SUCCEEDED(IMMDeviceEnumerator_GetDevice(enumerator, pwstrDeviceId, &device))) {
194        IMMEndpoint *endpoint = NULL;
195        if (SUCCEEDED(IMMDevice_QueryInterface(device, &SDL_IID_IMMEndpoint, (void **) &endpoint))) {
196            EDataFlow flow;
197            if (SUCCEEDED(IMMEndpoint_GetDataFlow(endpoint, &flow))) {
198                const SDL_bool iscapture = (flow == eCapture);
199                if (dwNewState == DEVICE_STATE_ACTIVE) {
200                    char *utf8dev = GetWasapiDeviceName(device);
201                    if (utf8dev) {
202                        WASAPI_AddDevice(iscapture, utf8dev, pwstrDeviceId);
203                        SDL_free(utf8dev);
204                    }
205                } else {
206                    WASAPI_RemoveDevice(iscapture, pwstrDeviceId);
207                }
208            }
209            IMMEndpoint_Release(endpoint);
210        }
211        IMMDevice_Release(device);
212    }
213
214    return S_OK;
215}
216
217static HRESULT STDMETHODCALLTYPE
218SDLMMNotificationClient_OnPropertyValueChanged(IMMNotificationClient *this, LPCWSTR pwstrDeviceId, const PROPERTYKEY key)
219{
220    return S_OK;  /* we don't care about these. */
221}
222
223static const IMMNotificationClientVtbl notification_client_vtbl = {
224    SDLMMNotificationClient_QueryInterface,
225    SDLMMNotificationClient_AddRef,
226    SDLMMNotificationClient_Release,
227    SDLMMNotificationClient_OnDeviceStateChanged,
228    SDLMMNotificationClient_OnDeviceAdded,
229    SDLMMNotificationClient_OnDeviceRemoved,
230    SDLMMNotificationClient_OnDefaultDeviceChanged,
231    SDLMMNotificationClient_OnPropertyValueChanged
232};
233
234static SDLMMNotificationClient notification_client = { &notification_client_vtbl, { 1 } };
235
236
237int
238WASAPI_PlatformInit(void)
239{
240    HRESULT ret;
241
242    /* just skip the discussion with COM here. */
243    if (!WIN_IsWindowsVistaOrGreater()) {
244        return SDL_SetError("WASAPI support requires Windows Vista or later");
245    }
246
247    if (FAILED(WIN_CoInitialize())) {
248        return SDL_SetError("WASAPI: CoInitialize() failed");
249    }
250
251    ret = CoCreateInstance(&SDL_CLSID_MMDeviceEnumerator, NULL, CLSCTX_INPROC_SERVER, &SDL_IID_IMMDeviceEnumerator, (LPVOID) &enumerator);
252    if (FAILED(ret)) {
253        WIN_CoUninitialize();
254        return WIN_SetErrorFromHRESULT("WASAPI CoCreateInstance(MMDeviceEnumerator)", ret);
255    }
256
257    libavrt = LoadLibraryW(L"avrt.dll");  /* this library is available in Vista and later. No WinXP, so have to LoadLibrary to use it for now! */
258    if (libavrt) {
259        pAvSetMmThreadCharacteristicsW = (pfnAvSetMmThreadCharacteristicsW) GetProcAddress(libavrt, "AvSetMmThreadCharacteristicsW");
260        pAvRevertMmThreadCharacteristics = (pfnAvRevertMmThreadCharacteristics) GetProcAddress(libavrt, "AvRevertMmThreadCharacteristics");
261    }
262
263    return 0;
264}
265
266void
267WASAPI_PlatformDeinit(void)
268{
269    if (enumerator) {
270        IMMDeviceEnumerator_UnregisterEndpointNotificationCallback(enumerator, (IMMNotificationClient *) &notification_client);
271        IMMDeviceEnumerator_Release(enumerator);
272        enumerator = NULL;
273    }
274
275    if (libavrt) {
276        FreeLibrary(libavrt);
277        libavrt = NULL;
278    }
279
280    pAvSetMmThreadCharacteristicsW = NULL;
281    pAvRevertMmThreadCharacteristics = NULL;
282
283    WIN_CoUninitialize();
284}
285
286void
287WASAPI_PlatformThreadInit(_THIS)
288{
289    /* this thread uses COM. */
290    if (SUCCEEDED(WIN_CoInitialize())) {    /* can't report errors, hope it worked! */
291        this->hidden->coinitialized = SDL_TRUE;
292    }
293
294    /* Set this thread to very high "Pro Audio" priority. */
295    if (pAvSetMmThreadCharacteristicsW) {
296        DWORD idx = 0;
297        this->hidden->task = pAvSetMmThreadCharacteristicsW(TEXT("Pro Audio"), &idx);
298    }
299}
300
301void
302WASAPI_PlatformThreadDeinit(_THIS)
303{
304    /* Set this thread back to normal priority. */
305    if (this->hidden->task && pAvRevertMmThreadCharacteristics) {
306        pAvRevertMmThreadCharacteristics(this->hidden->task);
307        this->hidden->task = NULL;
308    }
309
310    if (this->hidden->coinitialized) {
311        WIN_CoUninitialize();
312        this->hidden->coinitialized = SDL_FALSE;
313    }
314}
315
316int
317WASAPI_ActivateDevice(_THIS, const SDL_bool isrecovery)
318{
319    LPCWSTR devid = this->hidden->devid;
320    IMMDevice *device = NULL;
321    HRESULT ret;
322
323    if (devid == NULL) {
324        const EDataFlow dataflow = this->iscapture ? eCapture : eRender;
325        ret = IMMDeviceEnumerator_GetDefaultAudioEndpoint(enumerator, dataflow, SDL_WASAPI_role, &device);
326    } else {
327        ret = IMMDeviceEnumerator_GetDevice(enumerator, devid, &device);
328    }
329
330    if (FAILED(ret)) {
331        SDL_assert(device == NULL);
332        this->hidden->client = NULL;
333        return WIN_SetErrorFromHRESULT("WASAPI can't find requested audio endpoint", ret);
334    }
335
336    /* this is not async in standard win32, yay! */
337    ret = IMMDevice_Activate(device, &SDL_IID_IAudioClient, CLSCTX_ALL, NULL, (void **) &this->hidden->client);
338    IMMDevice_Release(device);
339
340    if (FAILED(ret)) {
341        SDL_assert(this->hidden->client == NULL);
342        return WIN_SetErrorFromHRESULT("WASAPI can't activate audio endpoint", ret);
343    }
344
345    SDL_assert(this->hidden->client != NULL);
346    if (WASAPI_PrepDevice(this, isrecovery) == -1) {   /* not async, fire it right away. */
347        return -1;
348    }
349
350    return 0;  /* good to go. */
351}
352
353
354static void
355WASAPI_EnumerateEndpointsForFlow(const SDL_bool iscapture)
356{
357    IMMDeviceCollection *collection = NULL;
358    UINT i, total;
359
360    /* Note that WASAPI separates "adapter devices" from "audio endpoint devices"
361       ...one adapter device ("SoundBlaster Pro") might have multiple endpoint devices ("Speakers", "Line-Out"). */
362
363    if (FAILED(IMMDeviceEnumerator_EnumAudioEndpoints(enumerator, iscapture ? eCapture : eRender, DEVICE_STATE_ACTIVE, &collection))) {
364        return;
365    }
366
367    if (FAILED(IMMDeviceCollection_GetCount(collection, &total))) {
368        IMMDeviceCollection_Release(collection);
369        return;
370    }
371
372    for (i = 0; i < total; i++) {
373        IMMDevice *device = NULL;
374        if (SUCCEEDED(IMMDeviceCollection_Item(collection, i, &device))) {
375            LPWSTR devid = NULL;
376            if (SUCCEEDED(IMMDevice_GetId(device, &devid))) {
377                char *devname = GetWasapiDeviceName(device);
378                if (devname) {
379                    WASAPI_AddDevice(iscapture, devname, devid);
380                    SDL_free(devname);
381                }
382                CoTaskMemFree(devid);
383            }
384            IMMDevice_Release(device);
385        }
386    }
387
388    IMMDeviceCollection_Release(collection);
389}
390
391void
392WASAPI_EnumerateEndpoints(void)
393{
394    WASAPI_EnumerateEndpointsForFlow(SDL_FALSE);  /* playback */
395    WASAPI_EnumerateEndpointsForFlow(SDL_TRUE);  /* capture */
396
397    /* if this fails, we just won't get hotplug events. Carry on anyhow. */
398    IMMDeviceEnumerator_RegisterEndpointNotificationCallback(enumerator, (IMMNotificationClient *) &notification_client);
399}
400
401void
402WASAPI_PlatformDeleteActivationHandler(void *handler)
403{
404    /* not asynchronous. */
405    SDL_assert(!"This function should have only been called on WinRT.");
406}
407
408void
409WASAPI_BeginLoopIteration(_THIS)
410{
411    /* no-op. */
412}
413
414#endif  /* SDL_AUDIO_DRIVER_WASAPI && !defined(__WINRT__) */
415
416/* vi: set ts=4 sw=4 expandtab: */
417
418
[FILE END]
(C) 2025 0x4248
(C) 2025 4248 Media and 4248 Systems, All part of 0x4248
See LICENCE files for more information. Not all files are by 0x4248 always check Licencing.