xref: /openbmc/qemu/audio/sdlaudio.c (revision a719a27c)
1 /*
2  * QEMU SDL audio driver
3  *
4  * Copyright (c) 2004-2005 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 #include <SDL.h>
25 #include <SDL_thread.h>
26 #include "qemu-common.h"
27 #include "audio.h"
28 
29 #ifndef _WIN32
30 #ifdef __sun__
31 #define _POSIX_PTHREAD_SEMANTICS 1
32 #elif defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
33 #include <pthread.h>
34 #endif
35 #endif
36 
37 #define AUDIO_CAP "sdl"
38 #include "audio_int.h"
39 
40 typedef struct SDLVoiceOut {
41     HWVoiceOut hw;
42     int live;
43     int rpos;
44     int decr;
45 } SDLVoiceOut;
46 
47 static struct {
48     int nb_samples;
49 } conf = {
50     .nb_samples = 1024
51 };
52 
53 static struct SDLAudioState {
54     int exit;
55     SDL_mutex *mutex;
56     SDL_sem *sem;
57     int initialized;
58 } glob_sdl;
59 typedef struct SDLAudioState SDLAudioState;
60 
61 static void GCC_FMT_ATTR (1, 2) sdl_logerr (const char *fmt, ...)
62 {
63     va_list ap;
64 
65     va_start (ap, fmt);
66     AUD_vlog (AUDIO_CAP, fmt, ap);
67     va_end (ap);
68 
69     AUD_log (AUDIO_CAP, "Reason: %s\n", SDL_GetError ());
70 }
71 
72 static int sdl_lock (SDLAudioState *s, const char *forfn)
73 {
74     if (SDL_LockMutex (s->mutex)) {
75         sdl_logerr ("SDL_LockMutex for %s failed\n", forfn);
76         return -1;
77     }
78     return 0;
79 }
80 
81 static int sdl_unlock (SDLAudioState *s, const char *forfn)
82 {
83     if (SDL_UnlockMutex (s->mutex)) {
84         sdl_logerr ("SDL_UnlockMutex for %s failed\n", forfn);
85         return -1;
86     }
87     return 0;
88 }
89 
90 static int sdl_post (SDLAudioState *s, const char *forfn)
91 {
92     if (SDL_SemPost (s->sem)) {
93         sdl_logerr ("SDL_SemPost for %s failed\n", forfn);
94         return -1;
95     }
96     return 0;
97 }
98 
99 static int sdl_wait (SDLAudioState *s, const char *forfn)
100 {
101     if (SDL_SemWait (s->sem)) {
102         sdl_logerr ("SDL_SemWait for %s failed\n", forfn);
103         return -1;
104     }
105     return 0;
106 }
107 
108 static int sdl_unlock_and_post (SDLAudioState *s, const char *forfn)
109 {
110     if (sdl_unlock (s, forfn)) {
111         return -1;
112     }
113 
114     return sdl_post (s, forfn);
115 }
116 
117 static int aud_to_sdlfmt (audfmt_e fmt)
118 {
119     switch (fmt) {
120     case AUD_FMT_S8:
121         return AUDIO_S8;
122 
123     case AUD_FMT_U8:
124         return AUDIO_U8;
125 
126     case AUD_FMT_S16:
127         return AUDIO_S16LSB;
128 
129     case AUD_FMT_U16:
130         return AUDIO_U16LSB;
131 
132     default:
133         dolog ("Internal logic error: Bad audio format %d\n", fmt);
134 #ifdef DEBUG_AUDIO
135         abort ();
136 #endif
137         return AUDIO_U8;
138     }
139 }
140 
141 static int sdl_to_audfmt(int sdlfmt, audfmt_e *fmt, int *endianness)
142 {
143     switch (sdlfmt) {
144     case AUDIO_S8:
145         *endianness = 0;
146         *fmt = AUD_FMT_S8;
147         break;
148 
149     case AUDIO_U8:
150         *endianness = 0;
151         *fmt = AUD_FMT_U8;
152         break;
153 
154     case AUDIO_S16LSB:
155         *endianness = 0;
156         *fmt = AUD_FMT_S16;
157         break;
158 
159     case AUDIO_U16LSB:
160         *endianness = 0;
161         *fmt = AUD_FMT_U16;
162         break;
163 
164     case AUDIO_S16MSB:
165         *endianness = 1;
166         *fmt = AUD_FMT_S16;
167         break;
168 
169     case AUDIO_U16MSB:
170         *endianness = 1;
171         *fmt = AUD_FMT_U16;
172         break;
173 
174     default:
175         dolog ("Unrecognized SDL audio format %d\n", sdlfmt);
176         return -1;
177     }
178 
179     return 0;
180 }
181 
182 static int sdl_open (SDL_AudioSpec *req, SDL_AudioSpec *obt)
183 {
184     int status;
185 #ifndef _WIN32
186     int err;
187     sigset_t new, old;
188 
189     /* Make sure potential threads created by SDL don't hog signals.  */
190     err = sigfillset (&new);
191     if (err) {
192         dolog ("sdl_open: sigfillset failed: %s\n", strerror (errno));
193         return -1;
194     }
195     err = pthread_sigmask (SIG_BLOCK, &new, &old);
196     if (err) {
197         dolog ("sdl_open: pthread_sigmask failed: %s\n", strerror (err));
198         return -1;
199     }
200 #endif
201 
202     status = SDL_OpenAudio (req, obt);
203     if (status) {
204         sdl_logerr ("SDL_OpenAudio failed\n");
205     }
206 
207 #ifndef _WIN32
208     err = pthread_sigmask (SIG_SETMASK, &old, NULL);
209     if (err) {
210         dolog ("sdl_open: pthread_sigmask (restore) failed: %s\n",
211                strerror (errno));
212         /* We have failed to restore original signal mask, all bets are off,
213            so exit the process */
214         exit (EXIT_FAILURE);
215     }
216 #endif
217     return status;
218 }
219 
220 static void sdl_close (SDLAudioState *s)
221 {
222     if (s->initialized) {
223         sdl_lock (s, "sdl_close");
224         s->exit = 1;
225         sdl_unlock_and_post (s, "sdl_close");
226         SDL_PauseAudio (1);
227         SDL_CloseAudio ();
228         s->initialized = 0;
229     }
230 }
231 
232 static void sdl_callback (void *opaque, Uint8 *buf, int len)
233 {
234     SDLVoiceOut *sdl = opaque;
235     SDLAudioState *s = &glob_sdl;
236     HWVoiceOut *hw = &sdl->hw;
237     int samples = len >> hw->info.shift;
238 
239     if (s->exit) {
240         return;
241     }
242 
243     while (samples) {
244         int to_mix, decr;
245 
246         /* dolog ("in callback samples=%d\n", samples); */
247         sdl_wait (s, "sdl_callback");
248         if (s->exit) {
249             return;
250         }
251 
252         if (sdl_lock (s, "sdl_callback")) {
253             return;
254         }
255 
256         if (audio_bug (AUDIO_FUNC, sdl->live < 0 || sdl->live > hw->samples)) {
257             dolog ("sdl->live=%d hw->samples=%d\n",
258                    sdl->live, hw->samples);
259             return;
260         }
261 
262         if (!sdl->live) {
263             goto again;
264         }
265 
266         /* dolog ("in callback live=%d\n", live); */
267         to_mix = audio_MIN (samples, sdl->live);
268         decr = to_mix;
269         while (to_mix) {
270             int chunk = audio_MIN (to_mix, hw->samples - hw->rpos);
271             struct st_sample *src = hw->mix_buf + hw->rpos;
272 
273             /* dolog ("in callback to_mix %d, chunk %d\n", to_mix, chunk); */
274             hw->clip (buf, src, chunk);
275             sdl->rpos = (sdl->rpos + chunk) % hw->samples;
276             to_mix -= chunk;
277             buf += chunk << hw->info.shift;
278         }
279         samples -= decr;
280         sdl->live -= decr;
281         sdl->decr += decr;
282 
283     again:
284         if (sdl_unlock (s, "sdl_callback")) {
285             return;
286         }
287     }
288     /* dolog ("done len=%d\n", len); */
289 }
290 
291 static int sdl_write_out (SWVoiceOut *sw, void *buf, int len)
292 {
293     return audio_pcm_sw_write (sw, buf, len);
294 }
295 
296 static int sdl_run_out (HWVoiceOut *hw, int live)
297 {
298     int decr;
299     SDLVoiceOut *sdl = (SDLVoiceOut *) hw;
300     SDLAudioState *s = &glob_sdl;
301 
302     if (sdl_lock (s, "sdl_run_out")) {
303         return 0;
304     }
305 
306     if (sdl->decr > live) {
307         ldebug ("sdl->decr %d live %d sdl->live %d\n",
308                 sdl->decr,
309                 live,
310                 sdl->live);
311     }
312 
313     decr = audio_MIN (sdl->decr, live);
314     sdl->decr -= decr;
315 
316     sdl->live = live - decr;
317     hw->rpos = sdl->rpos;
318 
319     if (sdl->live > 0) {
320         sdl_unlock_and_post (s, "sdl_run_out");
321     }
322     else {
323         sdl_unlock (s, "sdl_run_out");
324     }
325     return decr;
326 }
327 
328 static void sdl_fini_out (HWVoiceOut *hw)
329 {
330     (void) hw;
331 
332     sdl_close (&glob_sdl);
333 }
334 
335 static int sdl_init_out (HWVoiceOut *hw, struct audsettings *as)
336 {
337     SDLVoiceOut *sdl = (SDLVoiceOut *) hw;
338     SDLAudioState *s = &glob_sdl;
339     SDL_AudioSpec req, obt;
340     int endianness;
341     int err;
342     audfmt_e effective_fmt;
343     struct audsettings obt_as;
344 
345     req.freq = as->freq;
346     req.format = aud_to_sdlfmt (as->fmt);
347     req.channels = as->nchannels;
348     req.samples = conf.nb_samples;
349     req.callback = sdl_callback;
350     req.userdata = sdl;
351 
352     if (sdl_open (&req, &obt)) {
353         return -1;
354     }
355 
356     err = sdl_to_audfmt(obt.format, &effective_fmt, &endianness);
357     if (err) {
358         sdl_close (s);
359         return -1;
360     }
361 
362     obt_as.freq = obt.freq;
363     obt_as.nchannels = obt.channels;
364     obt_as.fmt = effective_fmt;
365     obt_as.endianness = endianness;
366 
367     audio_pcm_init_info (&hw->info, &obt_as);
368     hw->samples = obt.samples;
369 
370     s->initialized = 1;
371     s->exit = 0;
372     SDL_PauseAudio (0);
373     return 0;
374 }
375 
376 static int sdl_ctl_out (HWVoiceOut *hw, int cmd, ...)
377 {
378     (void) hw;
379 
380     switch (cmd) {
381     case VOICE_ENABLE:
382         SDL_PauseAudio (0);
383         break;
384 
385     case VOICE_DISABLE:
386         SDL_PauseAudio (1);
387         break;
388     }
389     return 0;
390 }
391 
392 static void *sdl_audio_init (void)
393 {
394     SDLAudioState *s = &glob_sdl;
395 
396     if (SDL_InitSubSystem (SDL_INIT_AUDIO)) {
397         sdl_logerr ("SDL failed to initialize audio subsystem\n");
398         return NULL;
399     }
400 
401     s->mutex = SDL_CreateMutex ();
402     if (!s->mutex) {
403         sdl_logerr ("Failed to create SDL mutex\n");
404         SDL_QuitSubSystem (SDL_INIT_AUDIO);
405         return NULL;
406     }
407 
408     s->sem = SDL_CreateSemaphore (0);
409     if (!s->sem) {
410         sdl_logerr ("Failed to create SDL semaphore\n");
411         SDL_DestroyMutex (s->mutex);
412         SDL_QuitSubSystem (SDL_INIT_AUDIO);
413         return NULL;
414     }
415 
416     return s;
417 }
418 
419 static void sdl_audio_fini (void *opaque)
420 {
421     SDLAudioState *s = opaque;
422     sdl_close (s);
423     SDL_DestroySemaphore (s->sem);
424     SDL_DestroyMutex (s->mutex);
425     SDL_QuitSubSystem (SDL_INIT_AUDIO);
426 }
427 
428 static struct audio_option sdl_options[] = {
429     {
430         .name  = "SAMPLES",
431         .tag   = AUD_OPT_INT,
432         .valp  = &conf.nb_samples,
433         .descr = "Size of SDL buffer in samples"
434     },
435     { /* End of list */ }
436 };
437 
438 static struct audio_pcm_ops sdl_pcm_ops = {
439     .init_out = sdl_init_out,
440     .fini_out = sdl_fini_out,
441     .run_out  = sdl_run_out,
442     .write    = sdl_write_out,
443     .ctl_out  = sdl_ctl_out,
444 };
445 
446 struct audio_driver sdl_audio_driver = {
447     .name           = "sdl",
448     .descr          = "SDL http://www.libsdl.org",
449     .options        = sdl_options,
450     .init           = sdl_audio_init,
451     .fini           = sdl_audio_fini,
452     .pcm_ops        = &sdl_pcm_ops,
453     .can_be_default = 1,
454     .max_voices_out = 1,
455     .max_voices_in  = 0,
456     .voice_size_out = sizeof (SDLVoiceOut),
457     .voice_size_in  = 0
458 };
459