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 #define USE_SEMAPHORE (SDL_MAJOR_VERSION < 2)
  42
  43 typedef struct SDLVoiceOut {
  44     HWVoiceOut hw;
  45     int live;
  46 #if USE_SEMAPHORE
  47     int rpos;
  48 #endif
  49     int decr;
  50 } SDLVoiceOut;
  51
  52 static struct {
  53     int nb_samples;
  54 } conf = {
  55     .nb_samples = 1024
  56 };
  57
  58 static struct SDLAudioState {
  59     int exit;
  60 #if USE_SEMAPHORE
  61     SDL_mutex *mutex;
  62     SDL_sem *sem;
  63 #endif
  64     int initialized;
  65     bool driver_created;
  66 } glob_sdl;
  67 typedef struct SDLAudioState SDLAudioState;
  68
  69 static void GCC_FMT_ATTR (1, 2) sdl_logerr (const char *fmt, ...)
  70 {
  71     va_list ap;
  72
  73     va_start (ap, fmt);
  74     AUD_vlog (AUDIO_CAP, fmt, ap);
  75     va_end (ap);
  76
  77     AUD_log (AUDIO_CAP, "Reason: %s\n", SDL_GetError ());
  78 }
  79
  80 static int sdl_lock (SDLAudioState *s, const char *forfn)
  81 {
  82 #if USE_SEMAPHORE
  83     if (SDL_LockMutex (s->mutex)) {
  84         sdl_logerr ("SDL_LockMutex for %s failed\n", forfn);
  85         return -1;
  86     }
  87 #else
  88     SDL_LockAudio();
  89 #endif
  90
  91     return 0;
  92 }
  93
  94 static int sdl_unlock (SDLAudioState *s, const char *forfn)
  95 {
  96 #if USE_SEMAPHORE
  97     if (SDL_UnlockMutex (s->mutex)) {
  98         sdl_logerr ("SDL_UnlockMutex for %s failed\n", forfn);
  99         return -1;
 100     }
 101 #else
 102     SDL_UnlockAudio();
 103 #endif
 104
 105     return 0;
 106 }
 107
 108 static int sdl_post (SDLAudioState *s, const char *forfn)
 109 {
 110 #if USE_SEMAPHORE
 111     if (SDL_SemPost (s->sem)) {
 112         sdl_logerr ("SDL_SemPost for %s failed\n", forfn);
 113         return -1;
 114     }
 115 #endif
 116
 117     return 0;
 118 }
 119
 120 #if USE_SEMAPHORE
 121 static int sdl_wait (SDLAudioState *s, const char *forfn)
 122 {
 123     if (SDL_SemWait (s->sem)) {
 124         sdl_logerr ("SDL_SemWait for %s failed\n", forfn);
 125         return -1;
 126     }
 127     return 0;
 128 }
 129 #endif
 130
 131 static int sdl_unlock_and_post (SDLAudioState *s, const char *forfn)
 132 {
 133     if (sdl_unlock (s, forfn)) {
 134         return -1;
 135     }
 136
 137     return sdl_post (s, forfn);
 138 }
 139
 140 static int aud_to_sdlfmt (audfmt_e fmt)
 141 {
 142     switch (fmt) {
 143     case AUD_FMT_S8:
 144         return AUDIO_S8;
 145
 146     case AUD_FMT_U8:
 147         return AUDIO_U8;
 148
 149     case AUD_FMT_S16:
 150         return AUDIO_S16LSB;
 151
 152     case AUD_FMT_U16:
 153         return AUDIO_U16LSB;
 154
 155     default:
 156         dolog ("Internal logic error: Bad audio format %d\n", fmt);
 157 #ifdef DEBUG_AUDIO
 158         abort ();
 159 #endif
 160         return AUDIO_U8;
 161     }
 162 }
 163
 164 static int sdl_to_audfmt(int sdlfmt, audfmt_e *fmt, int *endianness)
 165 {
 166     switch (sdlfmt) {
 167     case AUDIO_S8:
 168         *endianness = 0;
 169         *fmt = AUD_FMT_S8;
 170         break;
 171
 172     case AUDIO_U8:
 173         *endianness = 0;
 174         *fmt = AUD_FMT_U8;
 175         break;
 176
 177     case AUDIO_S16LSB:
 178         *endianness = 0;
 179         *fmt = AUD_FMT_S16;
 180         break;
 181
 182     case AUDIO_U16LSB:
 183         *endianness = 0;
 184         *fmt = AUD_FMT_U16;
 185         break;
 186
 187     case AUDIO_S16MSB:
 188         *endianness = 1;
 189         *fmt = AUD_FMT_S16;
 190         break;
 191
 192     case AUDIO_U16MSB:
 193         *endianness = 1;
 194         *fmt = AUD_FMT_U16;
 195         break;
 196
 197     default:
 198         dolog ("Unrecognized SDL audio format %d\n", sdlfmt);
 199         return -1;
 200     }
 201
 202     return 0;
 203 }
 204
 205 static int sdl_open (SDL_AudioSpec *req, SDL_AudioSpec *obt)
 206 {
 207     int status;
 208 #ifndef _WIN32
 209     int err;
 210     sigset_t new, old;
 211
 212     /* Make sure potential threads created by SDL don't hog signals.  */
 213     err = sigfillset (&new);
 214     if (err) {
 215         dolog ("sdl_open: sigfillset failed: %s\n", strerror (errno));
 216         return -1;
 217     }
 218     err = pthread_sigmask (SIG_BLOCK, &new, &old);
 219     if (err) {
 220         dolog ("sdl_open: pthread_sigmask failed: %s\n", strerror (err));
 221         return -1;
 222     }
 223 #endif
 224
 225     status = SDL_OpenAudio (req, obt);
 226     if (status) {
 227         sdl_logerr ("SDL_OpenAudio failed\n");
 228     }
 229
 230 #ifndef _WIN32
 231     err = pthread_sigmask (SIG_SETMASK, &old, NULL);
 232     if (err) {
 233         dolog ("sdl_open: pthread_sigmask (restore) failed: %s\n",
 234                strerror (errno));
 235         /* We have failed to restore original signal mask, all bets are off,
 236            so exit the process */
 237         exit (EXIT_FAILURE);
 238     }
 239 #endif
 240     return status;
 241 }
 242
 243 static void sdl_close (SDLAudioState *s)
 244 {
 245     if (s->initialized) {
 246         sdl_lock (s, "sdl_close");
 247         s->exit = 1;
 248         sdl_unlock_and_post (s, "sdl_close");
 249         SDL_PauseAudio (1);
 250         SDL_CloseAudio ();
 251         s->initialized = 0;
 252     }
 253 }
 254
 255 static void sdl_callback (void *opaque, Uint8 *buf, int len)
 256 {
 257     SDLVoiceOut *sdl = opaque;
 258     SDLAudioState *s = &glob_sdl;
 259     HWVoiceOut *hw = &sdl->hw;
 260     int samples = len >> hw->info.shift;
 261
 262     if (s->exit) {
 263         return;
 264     }
 265
 266     while (samples) {
 267         int to_mix, decr;
 268
 269         /* dolog ("in callback samples=%d\n", samples); */
 270 #if USE_SEMAPHORE
 271         sdl_wait (s, "sdl_callback");
 272         if (s->exit) {
 273             return;
 274         }
 275
 276         if (sdl_lock (s, "sdl_callback")) {
 277             return;
 278         }
 279
 280         if (audio_bug (AUDIO_FUNC, sdl->live < 0 || sdl->live > hw->samples)) {
 281             dolog ("sdl->live=%d hw->samples=%d\n",
 282                    sdl->live, hw->samples);
 283             return;
 284         }
 285
 286         if (!sdl->live) {
 287             goto again;
 288         }
 289 #else
 290         if (s->exit || !sdl->live) {
 291             break;
 292         }
 293 #endif
 294
 295         /* dolog ("in callback live=%d\n", live); */
 296         to_mix = audio_MIN (samples, sdl->live);
 297         decr = to_mix;
 298         while (to_mix) {
 299             int chunk = audio_MIN (to_mix, hw->samples - hw->rpos);
 300             struct st_sample *src = hw->mix_buf + hw->rpos;
 301
 302             /* dolog ("in callback to_mix %d, chunk %d\n", to_mix, chunk); */
 303             hw->clip (buf, src, chunk);
 304 #if USE_SEMAPHORE
 305             sdl->rpos = (sdl->rpos + chunk) % hw->samples;
 306 #else
 307             hw->rpos = (hw->rpos + chunk) % hw->samples;
 308 #endif
 309             to_mix -= chunk;
 310             buf += chunk << hw->info.shift;
 311         }
 312         samples -= decr;
 313         sdl->live -= decr;
 314         sdl->decr += decr;
 315
 316 #if USE_SEMAPHORE
 317     again:
 318         if (sdl_unlock (s, "sdl_callback")) {
 319             return;
 320         }
 321 #endif
 322     }
 323     /* dolog ("done len=%d\n", len); */
 324
 325 #if (SDL_MAJOR_VERSION >= 2)
 326     /* SDL2 does not clear the remaining buffer for us, so do it on our own */
 327     if (samples) {
 328         memset(buf, 0, samples << hw->info.shift);
 329     }
 330 #endif
 331 }
 332
 333 static int sdl_write_out (SWVoiceOut *sw, void *buf, int len)
 334 {
 335     return audio_pcm_sw_write (sw, buf, len);
 336 }
 337
 338 static int sdl_run_out (HWVoiceOut *hw, int live)
 339 {
 340     int decr;
 341     SDLVoiceOut *sdl = (SDLVoiceOut *) hw;
 342     SDLAudioState *s = &glob_sdl;
 343
 344     if (sdl_lock (s, "sdl_run_out")) {
 345         return 0;
 346     }
 347
 348     if (sdl->decr > live) {
 349         ldebug ("sdl->decr %d live %d sdl->live %d\n",
 350                 sdl->decr,
 351                 live,
 352                 sdl->live);
 353     }
 354
 355     decr = audio_MIN (sdl->decr, live);
 356     sdl->decr -= decr;
 357
 358 #if USE_SEMAPHORE
 359     sdl->live = live - decr;
 360     hw->rpos = sdl->rpos;
 361 #else
 362     sdl->live = live;
 363 #endif
 364
 365     if (sdl->live > 0) {
 366         sdl_unlock_and_post (s, "sdl_run_out");
 367     }
 368     else {
 369         sdl_unlock (s, "sdl_run_out");
 370     }
 371     return decr;
 372 }
 373
 374 static void sdl_fini_out (HWVoiceOut *hw)
 375 {
 376     (void) hw;
 377
 378     sdl_close (&glob_sdl);
 379 }
 380
 381 static int sdl_init_out(HWVoiceOut *hw, struct audsettings *as,
 382                         void *drv_opaque)
 383 {
 384     SDLVoiceOut *sdl = (SDLVoiceOut *) hw;
 385     SDLAudioState *s = &glob_sdl;
 386     SDL_AudioSpec req, obt;
 387     int endianness;
 388     int err;
 389     audfmt_e effective_fmt;
 390     struct audsettings obt_as;
 391
 392     req.freq = as->freq;
 393     req.format = aud_to_sdlfmt (as->fmt);
 394     req.channels = as->nchannels;
 395     req.samples = conf.nb_samples;
 396     req.callback = sdl_callback;
 397     req.userdata = sdl;
 398
 399     if (sdl_open (&req, &obt)) {
 400         return -1;
 401     }
 402
 403     err = sdl_to_audfmt(obt.format, &effective_fmt, &endianness);
 404     if (err) {
 405         sdl_close (s);
 406         return -1;
 407     }
 408
 409     obt_as.freq = obt.freq;
 410     obt_as.nchannels = obt.channels;
 411     obt_as.fmt = effective_fmt;
 412     obt_as.endianness = endianness;
 413
 414     audio_pcm_init_info (&hw->info, &obt_as);
 415     hw->samples = obt.samples;
 416
 417     s->initialized = 1;
 418     s->exit = 0;
 419     SDL_PauseAudio (0);
 420     return 0;
 421 }
 422
 423 static int sdl_ctl_out (HWVoiceOut *hw, int cmd, ...)
 424 {
 425     (void) hw;
 426
 427     switch (cmd) {
 428     case VOICE_ENABLE:
 429         SDL_PauseAudio (0);
 430         break;
 431
 432     case VOICE_DISABLE:
 433         SDL_PauseAudio (1);
 434         break;
 435     }
 436     return 0;
 437 }
 438
 439 static void *sdl_audio_init (void)
 440 {
 441     SDLAudioState *s = &glob_sdl;
 442     if (s->driver_created) {
 443         sdl_logerr("Can't create multiple sdl backends\n");
 444         return NULL;
 445     }
 446
 447     if (SDL_InitSubSystem (SDL_INIT_AUDIO)) {
 448         sdl_logerr ("SDL failed to initialize audio subsystem\n");
 449         return NULL;
 450     }
 451
 452 #if USE_SEMAPHORE
 453     s->mutex = SDL_CreateMutex ();
 454     if (!s->mutex) {
 455         sdl_logerr ("Failed to create SDL mutex\n");
 456         SDL_QuitSubSystem (SDL_INIT_AUDIO);
 457         return NULL;
 458     }
 459
 460     s->sem = SDL_CreateSemaphore (0);
 461     if (!s->sem) {
 462         sdl_logerr ("Failed to create SDL semaphore\n");
 463         SDL_DestroyMutex (s->mutex);
 464         SDL_QuitSubSystem (SDL_INIT_AUDIO);
 465         return NULL;
 466     }
 467 #endif
 468
 469     s->driver_created = true;
 470     return s;
 471 }
 472
 473 static void sdl_audio_fini (void *opaque)
 474 {
 475     SDLAudioState *s = opaque;
 476     sdl_close (s);
 477 #if USE_SEMAPHORE
 478     SDL_DestroySemaphore (s->sem);
 479     SDL_DestroyMutex (s->mutex);
 480 #endif
 481     SDL_QuitSubSystem (SDL_INIT_AUDIO);
 482     s->driver_created = false;
 483 }
 484
 485 static struct audio_option sdl_options[] = {
 486     {
 487         .name  = "SAMPLES",
 488         .tag   = AUD_OPT_INT,
 489         .valp  = &conf.nb_samples,
 490         .descr = "Size of SDL buffer in samples"
 491     },
 492     { /* End of list */ }
 493 };
 494
 495 static struct audio_pcm_ops sdl_pcm_ops = {
 496     .init_out = sdl_init_out,
 497     .fini_out = sdl_fini_out,
 498     .run_out  = sdl_run_out,
 499     .write    = sdl_write_out,
 500     .ctl_out  = sdl_ctl_out,
 501 };
 502
 503 struct audio_driver sdl_audio_driver = {
 504     .name           = "sdl",
 505     .descr          = "SDL http://www.libsdl.org",
 506     .options        = sdl_options,
 507     .init           = sdl_audio_init,
 508     .fini           = sdl_audio_fini,
 509     .pcm_ops        = &sdl_pcm_ops,
 510     .can_be_default = 1,
 511     .max_voices_out = 1,
 512     .max_voices_in  = 0,
 513     .voice_size_out = sizeof (SDLVoiceOut),
 514     .voice_size_in  = 0
 515 };