audio/sdlaudio.c

   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 "qemu/osdep.h"
  25 #include <SDL.h>
  26 #include <SDL_thread.h>
  27 #include "qemu-common.h"
  28 #include "audio.h"
  29
  30 #ifndef _WIN32
  31 #ifdef __sun__
  32 #define _POSIX_PTHREAD_SEMANTICS 1
  33 #elif defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
  34 #include <pthread.h>
  35 #endif
  36 #endif
  37
  38 #define AUDIO_CAP "sdl"
  39 #include "audio_int.h"
  40
  41 typedef struct SDLVoiceOut {
  42     HWVoiceOut hw;
  43     int live;
  44     int rpos;
  45     int decr;
  46 } SDLVoiceOut;
  47
  48 static struct {
  49     int nb_samples;
  50 } conf = {
  51     .nb_samples = 1024
  52 };
  53
  54 static struct SDLAudioState {
  55     int exit;
  56     SDL_mutex *mutex;
  57     SDL_sem *sem;
  58     int initialized;
  59     bool driver_created;
  60 } glob_sdl;
  61 typedef struct SDLAudioState SDLAudioState;
  62
  63 static void GCC_FMT_ATTR (1, 2) sdl_logerr (const char *fmt, ...)
  64 {
  65     va_list ap;
  66
  67     va_start (ap, fmt);
  68     AUD_vlog (AUDIO_CAP, fmt, ap);
  69     va_end (ap);
  70
  71     AUD_log (AUDIO_CAP, "Reason: %s\n", SDL_GetError ());
  72 }
  73
  74 static int sdl_lock (SDLAudioState *s, const char *forfn)
  75 {
  76     if (SDL_LockMutex (s->mutex)) {
  77         sdl_logerr ("SDL_LockMutex for %s failed\n", forfn);
  78         return -1;
  79     }
  80     return 0;
  81 }
  82
  83 static int sdl_unlock (SDLAudioState *s, const char *forfn)
  84 {
  85     if (SDL_UnlockMutex (s->mutex)) {
  86         sdl_logerr ("SDL_UnlockMutex for %s failed\n", forfn);
  87         return -1;
  88     }
  89     return 0;
  90 }
  91
  92 static int sdl_post (SDLAudioState *s, const char *forfn)
  93 {
  94     if (SDL_SemPost (s->sem)) {
  95         sdl_logerr ("SDL_SemPost for %s failed\n", forfn);
  96         return -1;
  97     }
  98     return 0;
  99 }
 100
 101 static int sdl_wait (SDLAudioState *s, const char *forfn)
 102 {
 103     if (SDL_SemWait (s->sem)) {
 104         sdl_logerr ("SDL_SemWait for %s failed\n", forfn);
 105         return -1;
 106     }
 107     return 0;
 108 }
 109
 110 static int sdl_unlock_and_post (SDLAudioState *s, const char *forfn)
 111 {
 112     if (sdl_unlock (s, forfn)) {
 113         return -1;
 114     }
 115
 116     return sdl_post (s, forfn);
 117 }
 118
 119 static int aud_to_sdlfmt (audfmt_e fmt)
 120 {
 121     switch (fmt) {
 122     case AUD_FMT_S8:
 123         return AUDIO_S8;
 124
 125     case AUD_FMT_U8:
 126         return AUDIO_U8;
 127
 128     case AUD_FMT_S16:
 129         return AUDIO_S16LSB;
 130
 131     case AUD_FMT_U16:
 132         return AUDIO_U16LSB;
 133
 134     default:
 135         dolog ("Internal logic error: Bad audio format %d\n", fmt);
 136 #ifdef DEBUG_AUDIO
 137         abort ();
 138 #endif
 139         return AUDIO_U8;
 140     }
 141 }
 142
 143 static int sdl_to_audfmt(int sdlfmt, audfmt_e *fmt, int *endianness)
 144 {
 145     switch (sdlfmt) {
 146     case AUDIO_S8:
 147         *endianness = 0;
 148         *fmt = AUD_FMT_S8;
 149         break;
 150
 151     case AUDIO_U8:
 152         *endianness = 0;
 153         *fmt = AUD_FMT_U8;
 154         break;
 155
 156     case AUDIO_S16LSB:
 157         *endianness = 0;
 158         *fmt = AUD_FMT_S16;
 159         break;
 160
 161     case AUDIO_U16LSB:
 162         *endianness = 0;
 163         *fmt = AUD_FMT_U16;
 164         break;
 165
 166     case AUDIO_S16MSB:
 167         *endianness = 1;
 168         *fmt = AUD_FMT_S16;
 169         break;
 170
 171     case AUDIO_U16MSB:
 172         *endianness = 1;
 173         *fmt = AUD_FMT_U16;
 174         break;
 175
 176     default:
 177         dolog ("Unrecognized SDL audio format %d\n", sdlfmt);
 178         return -1;
 179     }
 180
 181     return 0;
 182 }
 183
 184 static int sdl_open (SDL_AudioSpec *req, SDL_AudioSpec *obt)
 185 {
 186     int status;
 187 #ifndef _WIN32
 188     int err;
 189     sigset_t new, old;
 190
 191     /* Make sure potential threads created by SDL don't hog signals.  */
 192     err = sigfillset (&new);
 193     if (err) {
 194         dolog ("sdl_open: sigfillset failed: %s\n", strerror (errno));
 195         return -1;
 196     }
 197     err = pthread_sigmask (SIG_BLOCK, &new, &old);
 198     if (err) {
 199         dolog ("sdl_open: pthread_sigmask failed: %s\n", strerror (err));
 200         return -1;
 201     }
 202 #endif
 203
 204     status = SDL_OpenAudio (req, obt);
 205     if (status) {
 206         sdl_logerr ("SDL_OpenAudio failed\n");
 207     }
 208
 209 #ifndef _WIN32
 210     err = pthread_sigmask (SIG_SETMASK, &old, NULL);
 211     if (err) {
 212         dolog ("sdl_open: pthread_sigmask (restore) failed: %s\n",
 213                strerror (errno));
 214         /* We have failed to restore original signal mask, all bets are off,
 215            so exit the process */
 216         exit (EXIT_FAILURE);
 217     }
 218 #endif
 219     return status;
 220 }
 221
 222 static void sdl_close (SDLAudioState *s)
 223 {
 224     if (s->initialized) {
 225         sdl_lock (s, "sdl_close");
 226         s->exit = 1;
 227         sdl_unlock_and_post (s, "sdl_close");
 228         SDL_PauseAudio (1);
 229         SDL_CloseAudio ();
 230         s->initialized = 0;
 231     }
 232 }
 233
 234 static void sdl_callback (void *opaque, Uint8 *buf, int len)
 235 {
 236     SDLVoiceOut *sdl = opaque;
 237     SDLAudioState *s = &glob_sdl;
 238     HWVoiceOut *hw = &sdl->hw;
 239     int samples = len >> hw->info.shift;
 240
 241     if (s->exit) {
 242         return;
 243     }
 244
 245     while (samples) {
 246         int to_mix, decr;
 247
 248         /* dolog ("in callback samples=%d\n", samples); */
 249         sdl_wait (s, "sdl_callback");
 250         if (s->exit) {
 251             return;
 252         }
 253
 254         if (sdl_lock (s, "sdl_callback")) {
 255             return;
 256         }
 257
 258         if (audio_bug (AUDIO_FUNC, sdl->live < 0 || sdl->live > hw->samples)) {
 259             dolog ("sdl->live=%d hw->samples=%d\n",
 260                    sdl->live, hw->samples);
 261             return;
 262         }
 263
 264         if (!sdl->live) {
 265             goto again;
 266         }
 267
 268         /* dolog ("in callback live=%d\n", live); */
 269         to_mix = audio_MIN (samples, sdl->live);
 270         decr = to_mix;
 271         while (to_mix) {
 272             int chunk = audio_MIN (to_mix, hw->samples - hw->rpos);
 273             struct st_sample *src = hw->mix_buf + hw->rpos;
 274
 275             /* dolog ("in callback to_mix %d, chunk %d\n", to_mix, chunk); */
 276             hw->clip (buf, src, chunk);
 277             sdl->rpos = (sdl->rpos + chunk) % hw->samples;
 278             to_mix -= chunk;
 279             buf += chunk << hw->info.shift;
 280         }
 281         samples -= decr;
 282         sdl->live -= decr;
 283         sdl->decr += decr;
 284
 285     again:
 286         if (sdl_unlock (s, "sdl_callback")) {
 287             return;
 288         }
 289     }
 290     /* dolog ("done len=%d\n", len); */
 291 }
 292
 293 static int sdl_write_out (SWVoiceOut *sw, void *buf, int len)
 294 {
 295     return audio_pcm_sw_write (sw, buf, len);
 296 }
 297
 298 static int sdl_run_out (HWVoiceOut *hw, int live)
 299 {
 300     int decr;
 301     SDLVoiceOut *sdl = (SDLVoiceOut *) hw;
 302     SDLAudioState *s = &glob_sdl;
 303
 304     if (sdl_lock (s, "sdl_run_out")) {
 305         return 0;
 306     }
 307
 308     if (sdl->decr > live) {
 309         ldebug ("sdl->decr %d live %d sdl->live %d\n",
 310                 sdl->decr,
 311                 live,
 312                 sdl->live);
 313     }
 314
 315     decr = audio_MIN (sdl->decr, live);
 316     sdl->decr -= decr;
 317
 318     sdl->live = live - decr;
 319     hw->rpos = sdl->rpos;
 320
 321     if (sdl->live > 0) {
 322         sdl_unlock_and_post (s, "sdl_run_out");
 323     }
 324     else {
 325         sdl_unlock (s, "sdl_run_out");
 326     }
 327     return decr;
 328 }
 329
 330 static void sdl_fini_out (HWVoiceOut *hw)
 331 {
 332     (void) hw;
 333
 334     sdl_close (&glob_sdl);
 335 }
 336
 337 static int sdl_init_out(HWVoiceOut *hw, struct audsettings *as,
 338                         void *drv_opaque)
 339 {
 340     SDLVoiceOut *sdl = (SDLVoiceOut *) hw;
 341     SDLAudioState *s = &glob_sdl;
 342     SDL_AudioSpec req, obt;
 343     int endianness;
 344     int err;
 345     audfmt_e effective_fmt;
 346     struct audsettings obt_as;
 347
 348     req.freq = as->freq;
 349     req.format = aud_to_sdlfmt (as->fmt);
 350     req.channels = as->nchannels;
 351     req.samples = conf.nb_samples;
 352     req.callback = sdl_callback;
 353     req.userdata = sdl;
 354
 355     if (sdl_open (&req, &obt)) {
 356         return -1;
 357     }
 358
 359     err = sdl_to_audfmt(obt.format, &effective_fmt, &endianness);
 360     if (err) {
 361         sdl_close (s);
 362         return -1;
 363     }
 364
 365     obt_as.freq = obt.freq;
 366     obt_as.nchannels = obt.channels;
 367     obt_as.fmt = effective_fmt;
 368     obt_as.endianness = endianness;
 369
 370     audio_pcm_init_info (&hw->info, &obt_as);
 371     hw->samples = obt.samples;
 372
 373     s->initialized = 1;
 374     s->exit = 0;
 375     SDL_PauseAudio (0);
 376     return 0;
 377 }
 378
 379 static int sdl_ctl_out (HWVoiceOut *hw, int cmd, ...)
 380 {
 381     (void) hw;
 382
 383     switch (cmd) {
 384     case VOICE_ENABLE:
 385         SDL_PauseAudio (0);
 386         break;
 387
 388     case VOICE_DISABLE:
 389         SDL_PauseAudio (1);
 390         break;
 391     }
 392     return 0;
 393 }
 394
 395 static void *sdl_audio_init (void)
 396 {
 397     SDLAudioState *s = &glob_sdl;
 398     if (s->driver_created) {
 399         sdl_logerr("Can't create multiple sdl backends\n");
 400         return NULL;
 401     }
 402
 403     if (SDL_InitSubSystem (SDL_INIT_AUDIO)) {
 404         sdl_logerr ("SDL failed to initialize audio subsystem\n");
 405         return NULL;
 406     }
 407
 408     s->mutex = SDL_CreateMutex ();
 409     if (!s->mutex) {
 410         sdl_logerr ("Failed to create SDL mutex\n");
 411         SDL_QuitSubSystem (SDL_INIT_AUDIO);
 412         return NULL;
 413     }
 414
 415     s->sem = SDL_CreateSemaphore (0);
 416     if (!s->sem) {
 417         sdl_logerr ("Failed to create SDL semaphore\n");
 418         SDL_DestroyMutex (s->mutex);
 419         SDL_QuitSubSystem (SDL_INIT_AUDIO);
 420         return NULL;
 421     }
 422
 423     s->driver_created = true;
 424     return s;
 425 }
 426
 427 static void sdl_audio_fini (void *opaque)
 428 {
 429     SDLAudioState *s = opaque;
 430     sdl_close (s);
 431     SDL_DestroySemaphore (s->sem);
 432     SDL_DestroyMutex (s->mutex);
 433     SDL_QuitSubSystem (SDL_INIT_AUDIO);
 434     s->driver_created = false;
 435 }
 436
 437 static struct audio_option sdl_options[] = {
 438     {
 439         .name  = "SAMPLES",
 440         .tag   = AUD_OPT_INT,
 441         .valp  = &conf.nb_samples,
 442         .descr = "Size of SDL buffer in samples"
 443     },
 444     { /* End of list */ }
 445 };
 446
 447 static struct audio_pcm_ops sdl_pcm_ops = {
 448     .init_out = sdl_init_out,
 449     .fini_out = sdl_fini_out,
 450     .run_out  = sdl_run_out,
 451     .write    = sdl_write_out,
 452     .ctl_out  = sdl_ctl_out,
 453 };
 454
 455 struct audio_driver sdl_audio_driver = {
 456     .name           = "sdl",
 457     .descr          = "SDL http://www.libsdl.org",
 458     .options        = sdl_options,
 459     .init           = sdl_audio_init,
 460     .fini           = sdl_audio_fini,
 461     .pcm_ops        = &sdl_pcm_ops,
 462     .can_be_default = 1,
 463     .max_voices_out = 1,
 464     .max_voices_in  = 0,
 465     .voice_size_out = sizeof (SDLVoiceOut),
 466     .voice_size_in  = 0
 467 };