qemu/audio/sdlaudio.c
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   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
  41typedef struct SDLVoiceOut {
  42    HWVoiceOut hw;
  43    int live;
  44    int rpos;
  45    int decr;
  46} SDLVoiceOut;
  47
  48static struct {
  49    int nb_samples;
  50} conf = {
  51    .nb_samples = 1024
  52};
  53
  54static struct SDLAudioState {
  55    int exit;
  56    SDL_mutex *mutex;
  57    SDL_sem *sem;
  58    int initialized;
  59    bool driver_created;
  60} glob_sdl;
  61typedef struct SDLAudioState SDLAudioState;
  62
  63static 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
  74static 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
  83static 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
  92static 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
 101static 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
 110static 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
 119static 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
 143static 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
 184static 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
 222static 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
 234static 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
 293static int sdl_write_out (SWVoiceOut *sw, void *buf, int len)
 294{
 295    return audio_pcm_sw_write (sw, buf, len);
 296}
 297
 298static 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
 330static void sdl_fini_out (HWVoiceOut *hw)
 331{
 332    (void) hw;
 333
 334    sdl_close (&glob_sdl);
 335}
 336
 337static 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
 379static 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
 395static 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
 427static 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
 437static 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
 447static 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
 455struct 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};
 468