xref: /openbmc/qemu/audio/dsoundaudio.c (revision 0ba4e76b)
1 /*
2  * QEMU DirectSound audio driver
3  *
4  * Copyright (c) 2005 Vassili Karpov (malc)
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 /*
26  * SEAL 1.07 by Carlos 'pel' Hasan was used as documentation
27  */
28 
29 #include "qemu/osdep.h"
30 #include "audio.h"
31 
32 #define AUDIO_CAP "dsound"
33 #include "audio_int.h"
34 #include "qemu/host-utils.h"
35 #include "qemu/module.h"
36 
37 #include <windows.h>
38 #include <mmsystem.h>
39 #include <objbase.h>
40 #include <dsound.h>
41 
42 #include "audio_win_int.h"
43 
44 /* #define DEBUG_DSOUND */
45 
46 typedef struct {
47     LPDIRECTSOUND dsound;
48     LPDIRECTSOUNDCAPTURE dsound_capture;
49     struct audsettings settings;
50     Audiodev *dev;
51 } dsound;
52 
53 typedef struct {
54     HWVoiceOut hw;
55     LPDIRECTSOUNDBUFFER dsound_buffer;
56     bool first_time;
57     dsound *s;
58 } DSoundVoiceOut;
59 
60 typedef struct {
61     HWVoiceIn hw;
62     LPDIRECTSOUNDCAPTUREBUFFER dsound_capture_buffer;
63     bool first_time;
64     dsound *s;
65 } DSoundVoiceIn;
66 
67 static void dsound_log_hresult (HRESULT hr)
68 {
69     const char *str = "BUG";
70 
71     switch (hr) {
72     case DS_OK:
73         str = "The method succeeded";
74         break;
75 #ifdef DS_NO_VIRTUALIZATION
76     case DS_NO_VIRTUALIZATION:
77         str = "The buffer was created, but another 3D algorithm was substituted";
78         break;
79 #endif
80 #ifdef DS_INCOMPLETE
81     case DS_INCOMPLETE:
82         str = "The method succeeded, but not all the optional effects were obtained";
83         break;
84 #endif
85 #ifdef DSERR_ACCESSDENIED
86     case DSERR_ACCESSDENIED:
87         str = "The request failed because access was denied";
88         break;
89 #endif
90 #ifdef DSERR_ALLOCATED
91     case DSERR_ALLOCATED:
92         str = "The request failed because resources, "
93               "such as a priority level, were already in use "
94               "by another caller";
95         break;
96 #endif
97 #ifdef DSERR_ALREADYINITIALIZED
98     case DSERR_ALREADYINITIALIZED:
99         str = "The object is already initialized";
100         break;
101 #endif
102 #ifdef DSERR_BADFORMAT
103     case DSERR_BADFORMAT:
104         str = "The specified wave format is not supported";
105         break;
106 #endif
107 #ifdef DSERR_BADSENDBUFFERGUID
108     case DSERR_BADSENDBUFFERGUID:
109         str = "The GUID specified in an audiopath file "
110               "does not match a valid mix-in buffer";
111         break;
112 #endif
113 #ifdef DSERR_BUFFERLOST
114     case DSERR_BUFFERLOST:
115         str = "The buffer memory has been lost and must be restored";
116         break;
117 #endif
118 #ifdef DSERR_BUFFERTOOSMALL
119     case DSERR_BUFFERTOOSMALL:
120         str = "The buffer size is not great enough to "
121               "enable effects processing";
122         break;
123 #endif
124 #ifdef DSERR_CONTROLUNAVAIL
125     case DSERR_CONTROLUNAVAIL:
126         str = "The buffer control (volume, pan, and so on) "
127               "requested by the caller is not available. "
128               "Controls must be specified when the buffer is created, "
129               "using the dwFlags member of DSBUFFERDESC";
130         break;
131 #endif
132 #ifdef DSERR_DS8_REQUIRED
133     case DSERR_DS8_REQUIRED:
134         str = "A DirectSound object of class CLSID_DirectSound8 or later "
135               "is required for the requested functionality. "
136               "For more information, see IDirectSound8 Interface";
137         break;
138 #endif
139 #ifdef DSERR_FXUNAVAILABLE
140     case DSERR_FXUNAVAILABLE:
141         str = "The effects requested could not be found on the system, "
142               "or they are in the wrong order or in the wrong location; "
143               "for example, an effect expected in hardware "
144               "was found in software";
145         break;
146 #endif
147 #ifdef DSERR_GENERIC
148     case DSERR_GENERIC:
149         str = "An undetermined error occurred inside the DirectSound subsystem";
150         break;
151 #endif
152 #ifdef DSERR_INVALIDCALL
153     case DSERR_INVALIDCALL:
154         str = "This function is not valid for the current state of this object";
155         break;
156 #endif
157 #ifdef DSERR_INVALIDPARAM
158     case DSERR_INVALIDPARAM:
159         str = "An invalid parameter was passed to the returning function";
160         break;
161 #endif
162 #ifdef DSERR_NOAGGREGATION
163     case DSERR_NOAGGREGATION:
164         str = "The object does not support aggregation";
165         break;
166 #endif
167 #ifdef DSERR_NODRIVER
168     case DSERR_NODRIVER:
169         str = "No sound driver is available for use, "
170               "or the given GUID is not a valid DirectSound device ID";
171         break;
172 #endif
173 #ifdef DSERR_NOINTERFACE
174     case DSERR_NOINTERFACE:
175         str = "The requested COM interface is not available";
176         break;
177 #endif
178 #ifdef DSERR_OBJECTNOTFOUND
179     case DSERR_OBJECTNOTFOUND:
180         str = "The requested object was not found";
181         break;
182 #endif
183 #ifdef DSERR_OTHERAPPHASPRIO
184     case DSERR_OTHERAPPHASPRIO:
185         str = "Another application has a higher priority level, "
186               "preventing this call from succeeding";
187         break;
188 #endif
189 #ifdef DSERR_OUTOFMEMORY
190     case DSERR_OUTOFMEMORY:
191         str = "The DirectSound subsystem could not allocate "
192                "sufficient memory to complete the caller's request";
193         break;
194 #endif
195 #ifdef DSERR_PRIOLEVELNEEDED
196     case DSERR_PRIOLEVELNEEDED:
197         str = "A cooperative level of DSSCL_PRIORITY or higher is required";
198         break;
199 #endif
200 #ifdef DSERR_SENDLOOP
201     case DSERR_SENDLOOP:
202         str = "A circular loop of send effects was detected";
203         break;
204 #endif
205 #ifdef DSERR_UNINITIALIZED
206     case DSERR_UNINITIALIZED:
207         str = "The Initialize method has not been called "
208               "or has not been called successfully "
209               "before other methods were called";
210         break;
211 #endif
212 #ifdef DSERR_UNSUPPORTED
213     case DSERR_UNSUPPORTED:
214         str = "The function called is not supported at this time";
215         break;
216 #endif
217     default:
218         AUD_log (AUDIO_CAP, "Reason: Unknown (HRESULT 0x%lx)\n", hr);
219         return;
220     }
221 
222     AUD_log (AUDIO_CAP, "Reason: %s\n", str);
223 }
224 
225 static void GCC_FMT_ATTR (2, 3) dsound_logerr (
226     HRESULT hr,
227     const char *fmt,
228     ...
229     )
230 {
231     va_list ap;
232 
233     va_start (ap, fmt);
234     AUD_vlog (AUDIO_CAP, fmt, ap);
235     va_end (ap);
236 
237     dsound_log_hresult (hr);
238 }
239 
240 static void GCC_FMT_ATTR (3, 4) dsound_logerr2 (
241     HRESULT hr,
242     const char *typ,
243     const char *fmt,
244     ...
245     )
246 {
247     va_list ap;
248 
249     AUD_log (AUDIO_CAP, "Could not initialize %s\n", typ);
250     va_start (ap, fmt);
251     AUD_vlog (AUDIO_CAP, fmt, ap);
252     va_end (ap);
253 
254     dsound_log_hresult (hr);
255 }
256 
257 #ifdef DEBUG_DSOUND
258 static void print_wave_format (WAVEFORMATEX *wfx)
259 {
260     dolog ("tag             = %d\n", wfx->wFormatTag);
261     dolog ("nChannels       = %d\n", wfx->nChannels);
262     dolog ("nSamplesPerSec  = %ld\n", wfx->nSamplesPerSec);
263     dolog ("nAvgBytesPerSec = %ld\n", wfx->nAvgBytesPerSec);
264     dolog ("nBlockAlign     = %d\n", wfx->nBlockAlign);
265     dolog ("wBitsPerSample  = %d\n", wfx->wBitsPerSample);
266     dolog ("cbSize          = %d\n", wfx->cbSize);
267 }
268 #endif
269 
270 static int dsound_restore_out (LPDIRECTSOUNDBUFFER dsb, dsound *s)
271 {
272     HRESULT hr;
273 
274     hr = IDirectSoundBuffer_Restore (dsb);
275 
276     if (hr != DS_OK) {
277         dsound_logerr (hr, "Could not restore playback buffer\n");
278         return -1;
279     }
280     return 0;
281 }
282 
283 #include "dsound_template.h"
284 #define DSBTYPE_IN
285 #include "dsound_template.h"
286 #undef DSBTYPE_IN
287 
288 static int dsound_get_status_out (LPDIRECTSOUNDBUFFER dsb, DWORD *statusp,
289                                   dsound *s)
290 {
291     HRESULT hr;
292 
293     hr = IDirectSoundBuffer_GetStatus (dsb, statusp);
294     if (FAILED (hr)) {
295         dsound_logerr (hr, "Could not get playback buffer status\n");
296         return -1;
297     }
298 
299     if (*statusp & DSBSTATUS_BUFFERLOST) {
300         dsound_restore_out(dsb, s);
301         return -1;
302     }
303 
304     return 0;
305 }
306 
307 static int dsound_get_status_in (LPDIRECTSOUNDCAPTUREBUFFER dscb,
308                                  DWORD *statusp)
309 {
310     HRESULT hr;
311 
312     hr = IDirectSoundCaptureBuffer_GetStatus (dscb, statusp);
313     if (FAILED (hr)) {
314         dsound_logerr (hr, "Could not get capture buffer status\n");
315         return -1;
316     }
317 
318     return 0;
319 }
320 
321 static void dsound_clear_sample (HWVoiceOut *hw, LPDIRECTSOUNDBUFFER dsb,
322                                  dsound *s)
323 {
324     int err;
325     LPVOID p1, p2;
326     DWORD blen1, blen2, len1, len2;
327 
328     err = dsound_lock_out (
329         dsb,
330         &hw->info,
331         0,
332         hw->size_emul,
333         &p1, &p2,
334         &blen1, &blen2,
335         1,
336         s
337         );
338     if (err) {
339         return;
340     }
341 
342     len1 = blen1 / hw->info.bytes_per_frame;
343     len2 = blen2 / hw->info.bytes_per_frame;
344 
345 #ifdef DEBUG_DSOUND
346     dolog ("clear %p,%ld,%ld %p,%ld,%ld\n",
347            p1, blen1, len1,
348            p2, blen2, len2);
349 #endif
350 
351     if (p1 && len1) {
352         audio_pcm_info_clear_buf (&hw->info, p1, len1);
353     }
354 
355     if (p2 && len2) {
356         audio_pcm_info_clear_buf (&hw->info, p2, len2);
357     }
358 
359     dsound_unlock_out (dsb, p1, p2, blen1, blen2);
360 }
361 
362 static int dsound_set_cooperative_level(dsound *s)
363 {
364     HRESULT hr;
365     HWND hwnd;
366 
367     hwnd = GetDesktopWindow();
368     hr = IDirectSound_SetCooperativeLevel (
369         s->dsound,
370         hwnd,
371         DSSCL_PRIORITY
372         );
373 
374     if (FAILED (hr)) {
375         dsound_logerr (hr, "Could not set cooperative level for window %p\n",
376                        hwnd);
377         return -1;
378     }
379 
380     return 0;
381 }
382 
383 static void dsound_enable_out(HWVoiceOut *hw, bool enable)
384 {
385     HRESULT hr;
386     DWORD status;
387     DSoundVoiceOut *ds = (DSoundVoiceOut *) hw;
388     LPDIRECTSOUNDBUFFER dsb = ds->dsound_buffer;
389     dsound *s = ds->s;
390 
391     if (!dsb) {
392         dolog ("Attempt to control voice without a buffer\n");
393         return;
394     }
395 
396     if (enable) {
397         if (dsound_get_status_out (dsb, &status, s)) {
398             return;
399         }
400 
401         if (status & DSBSTATUS_PLAYING) {
402             dolog ("warning: Voice is already playing\n");
403             return;
404         }
405 
406         dsound_clear_sample (hw, dsb, s);
407 
408         hr = IDirectSoundBuffer_Play (dsb, 0, 0, DSBPLAY_LOOPING);
409         if (FAILED (hr)) {
410             dsound_logerr (hr, "Could not start playing buffer\n");
411             return;
412         }
413     } else {
414         if (dsound_get_status_out (dsb, &status, s)) {
415             return;
416         }
417 
418         if (status & DSBSTATUS_PLAYING) {
419             hr = IDirectSoundBuffer_Stop (dsb);
420             if (FAILED (hr)) {
421                 dsound_logerr (hr, "Could not stop playing buffer\n");
422                 return;
423             }
424         } else {
425             dolog ("warning: Voice is not playing\n");
426         }
427     }
428 }
429 
430 static size_t dsound_buffer_get_free(HWVoiceOut *hw)
431 {
432     DSoundVoiceOut *ds = (DSoundVoiceOut *) hw;
433     LPDIRECTSOUNDBUFFER dsb = ds->dsound_buffer;
434     HRESULT hr;
435     DWORD ppos, wpos;
436 
437     hr = IDirectSoundBuffer_GetCurrentPosition(
438         dsb, &ppos, ds->first_time ? &wpos : NULL);
439     if (FAILED(hr)) {
440         dsound_logerr(hr, "Could not get playback buffer position\n");
441         return 0;
442     }
443 
444     if (ds->first_time) {
445         hw->pos_emul = wpos;
446         ds->first_time = false;
447     }
448 
449     return audio_ring_dist(ppos, hw->pos_emul, hw->size_emul);
450 }
451 
452 static void *dsound_get_buffer_out(HWVoiceOut *hw, size_t *size)
453 {
454     DSoundVoiceOut *ds = (DSoundVoiceOut *)hw;
455     LPDIRECTSOUNDBUFFER dsb = ds->dsound_buffer;
456     DWORD act_size;
457     size_t req_size;
458     int err;
459     void *ret;
460 
461     req_size = MIN(*size, hw->size_emul - hw->pos_emul);
462     assert(req_size > 0);
463 
464     err = dsound_lock_out(dsb, &hw->info, hw->pos_emul, req_size, &ret, NULL,
465                           &act_size, NULL, false, ds->s);
466     if (err) {
467         dolog("Failed to lock buffer\n");
468         *size = 0;
469         return NULL;
470     }
471 
472     *size = act_size;
473     return ret;
474 }
475 
476 static size_t dsound_put_buffer_out(HWVoiceOut *hw, void *buf, size_t len)
477 {
478     DSoundVoiceOut *ds = (DSoundVoiceOut *) hw;
479     LPDIRECTSOUNDBUFFER dsb = ds->dsound_buffer;
480     int err = dsound_unlock_out(dsb, buf, NULL, len, 0);
481 
482     if (err) {
483         dolog("Failed to unlock buffer!!\n");
484         return 0;
485     }
486     hw->pos_emul = (hw->pos_emul + len) % hw->size_emul;
487 
488     return len;
489 }
490 
491 static void dsound_enable_in(HWVoiceIn *hw, bool enable)
492 {
493     HRESULT hr;
494     DWORD status;
495     DSoundVoiceIn *ds = (DSoundVoiceIn *) hw;
496     LPDIRECTSOUNDCAPTUREBUFFER dscb = ds->dsound_capture_buffer;
497 
498     if (!dscb) {
499         dolog ("Attempt to control capture voice without a buffer\n");
500         return;
501     }
502 
503     if (enable) {
504         if (dsound_get_status_in (dscb, &status)) {
505             return;
506         }
507 
508         if (status & DSCBSTATUS_CAPTURING) {
509             dolog ("warning: Voice is already capturing\n");
510             return;
511         }
512 
513         /* clear ?? */
514 
515         hr = IDirectSoundCaptureBuffer_Start (dscb, DSCBSTART_LOOPING);
516         if (FAILED (hr)) {
517             dsound_logerr (hr, "Could not start capturing\n");
518             return;
519         }
520     } else {
521         if (dsound_get_status_in (dscb, &status)) {
522             return;
523         }
524 
525         if (status & DSCBSTATUS_CAPTURING) {
526             hr = IDirectSoundCaptureBuffer_Stop (dscb);
527             if (FAILED (hr)) {
528                 dsound_logerr (hr, "Could not stop capturing\n");
529                 return;
530             }
531         } else {
532             dolog ("warning: Voice is not capturing\n");
533         }
534     }
535 }
536 
537 static void *dsound_get_buffer_in(HWVoiceIn *hw, size_t *size)
538 {
539     DSoundVoiceIn *ds = (DSoundVoiceIn *) hw;
540     LPDIRECTSOUNDCAPTUREBUFFER dscb = ds->dsound_capture_buffer;
541     HRESULT hr;
542     DWORD rpos, act_size;
543     size_t req_size;
544     int err;
545     void *ret;
546 
547     hr = IDirectSoundCaptureBuffer_GetCurrentPosition(dscb, NULL, &rpos);
548     if (FAILED(hr)) {
549         dsound_logerr(hr, "Could not get capture buffer position\n");
550         *size = 0;
551         return NULL;
552     }
553 
554     if (ds->first_time) {
555         hw->pos_emul = rpos;
556         ds->first_time = false;
557     }
558 
559     req_size = audio_ring_dist(rpos, hw->pos_emul, hw->size_emul);
560     req_size = MIN(*size, MIN(req_size, hw->size_emul - hw->pos_emul));
561 
562     if (req_size == 0) {
563         *size = 0;
564         return NULL;
565     }
566 
567     err = dsound_lock_in(dscb, &hw->info, hw->pos_emul, req_size, &ret, NULL,
568                          &act_size, NULL, false, ds->s);
569     if (err) {
570         dolog("Failed to lock buffer\n");
571         *size = 0;
572         return NULL;
573     }
574 
575     *size = act_size;
576     return ret;
577 }
578 
579 static void dsound_put_buffer_in(HWVoiceIn *hw, void *buf, size_t len)
580 {
581     DSoundVoiceIn *ds = (DSoundVoiceIn *) hw;
582     LPDIRECTSOUNDCAPTUREBUFFER dscb = ds->dsound_capture_buffer;
583     int err = dsound_unlock_in(dscb, buf, NULL, len, 0);
584 
585     if (err) {
586         dolog("Failed to unlock buffer!!\n");
587         return;
588     }
589     hw->pos_emul = (hw->pos_emul + len) % hw->size_emul;
590 }
591 
592 static void dsound_audio_fini (void *opaque)
593 {
594     HRESULT hr;
595     dsound *s = opaque;
596 
597     if (!s->dsound) {
598         g_free(s);
599         return;
600     }
601 
602     hr = IDirectSound_Release (s->dsound);
603     if (FAILED (hr)) {
604         dsound_logerr (hr, "Could not release DirectSound\n");
605     }
606     s->dsound = NULL;
607 
608     if (!s->dsound_capture) {
609         g_free(s);
610         return;
611     }
612 
613     hr = IDirectSoundCapture_Release (s->dsound_capture);
614     if (FAILED (hr)) {
615         dsound_logerr (hr, "Could not release DirectSoundCapture\n");
616     }
617     s->dsound_capture = NULL;
618 
619     g_free(s);
620 }
621 
622 static void *dsound_audio_init(Audiodev *dev)
623 {
624     int err;
625     HRESULT hr;
626     dsound *s = g_malloc0(sizeof(dsound));
627     AudiodevDsoundOptions *dso;
628 
629     assert(dev->driver == AUDIODEV_DRIVER_DSOUND);
630     s->dev = dev;
631     dso = &dev->u.dsound;
632 
633     if (!dso->has_latency) {
634         dso->has_latency = true;
635         dso->latency = 10000; /* 10 ms */
636     }
637 
638     hr = CoInitialize (NULL);
639     if (FAILED (hr)) {
640         dsound_logerr (hr, "Could not initialize COM\n");
641         g_free(s);
642         return NULL;
643     }
644 
645     hr = CoCreateInstance (
646         &CLSID_DirectSound,
647         NULL,
648         CLSCTX_ALL,
649         &IID_IDirectSound,
650         (void **) &s->dsound
651         );
652     if (FAILED (hr)) {
653         dsound_logerr (hr, "Could not create DirectSound instance\n");
654         g_free(s);
655         return NULL;
656     }
657 
658     hr = IDirectSound_Initialize (s->dsound, NULL);
659     if (FAILED (hr)) {
660         dsound_logerr (hr, "Could not initialize DirectSound\n");
661 
662         hr = IDirectSound_Release (s->dsound);
663         if (FAILED (hr)) {
664             dsound_logerr (hr, "Could not release DirectSound\n");
665         }
666         g_free(s);
667         return NULL;
668     }
669 
670     hr = CoCreateInstance (
671         &CLSID_DirectSoundCapture,
672         NULL,
673         CLSCTX_ALL,
674         &IID_IDirectSoundCapture,
675         (void **) &s->dsound_capture
676         );
677     if (FAILED (hr)) {
678         dsound_logerr (hr, "Could not create DirectSoundCapture instance\n");
679     } else {
680         hr = IDirectSoundCapture_Initialize (s->dsound_capture, NULL);
681         if (FAILED (hr)) {
682             dsound_logerr (hr, "Could not initialize DirectSoundCapture\n");
683 
684             hr = IDirectSoundCapture_Release (s->dsound_capture);
685             if (FAILED (hr)) {
686                 dsound_logerr (hr, "Could not release DirectSoundCapture\n");
687             }
688             s->dsound_capture = NULL;
689         }
690     }
691 
692     err = dsound_set_cooperative_level(s);
693     if (err) {
694         dsound_audio_fini (s);
695         return NULL;
696     }
697 
698     return s;
699 }
700 
701 static struct audio_pcm_ops dsound_pcm_ops = {
702     .init_out = dsound_init_out,
703     .fini_out = dsound_fini_out,
704     .write    = audio_generic_write,
705     .buffer_get_free = dsound_buffer_get_free,
706     .get_buffer_out = dsound_get_buffer_out,
707     .put_buffer_out = dsound_put_buffer_out,
708     .enable_out = dsound_enable_out,
709 
710     .init_in  = dsound_init_in,
711     .fini_in  = dsound_fini_in,
712     .read     = audio_generic_read,
713     .get_buffer_in = dsound_get_buffer_in,
714     .put_buffer_in = dsound_put_buffer_in,
715     .enable_in = dsound_enable_in,
716 };
717 
718 static struct audio_driver dsound_audio_driver = {
719     .name           = "dsound",
720     .descr          = "DirectSound http://wikipedia.org/wiki/DirectSound",
721     .init           = dsound_audio_init,
722     .fini           = dsound_audio_fini,
723     .pcm_ops        = &dsound_pcm_ops,
724     .can_be_default = 1,
725     .max_voices_out = INT_MAX,
726     .max_voices_in  = 1,
727     .voice_size_out = sizeof (DSoundVoiceOut),
728     .voice_size_in  = sizeof (DSoundVoiceIn)
729 };
730 
731 static void register_audio_dsound(void)
732 {
733     audio_driver_register(&dsound_audio_driver);
734 }
735 type_init(register_audio_dsound);
736