audio/audio.c

   1 /*
   2  * QEMU Audio subsystem
   3  *
   4  * Copyright (c) 2003-2004 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 <assert.h>
  25 #include "vl.h"
  26
  27 #define USE_SDL_AUDIO
  28 #define USE_WAV_AUDIO
  29
  30 #include "audio/audio_int.h"
  31
  32 #define dolog(...) AUD_log ("audio", __VA_ARGS__)
  33 #ifdef DEBUG
  34 #define ldebug(...) dolog (__VA_ARGS__)
  35 #else
  36 #define ldebug(...)
  37 #endif
  38
  39 #define QC_AUDIO_DRV    "QEMU_AUDIO_DRV"
  40 #define QC_VOICES       "QEMU_VOICES"
  41 #define QC_FIXED_FORMAT "QEMU_FIXED_FORMAT"
  42 #define QC_FIXED_FREQ   "QEMU_FIXED_FREQ"
  43
  44 static HWVoice *hw_voices;
  45
  46 AudioState audio_state = {
  47     1,                          /* use fixed settings */
  48     44100,                      /* fixed frequency */
  49     2,                          /* fixed channels */
  50     AUD_FMT_S16,                /* fixed format */
  51     1,                          /* number of hw voices */
  52     -1                          /* voice size */
  53 };
  54
  55 /* http://www.df.lth.se/~john_e/gems/gem002d.html */
  56 /* http://www.multi-platforms.com/Tips/PopCount.htm */
  57 uint32_t popcount (uint32_t u)
  58 {
  59     u = ((u&0x55555555) + ((u>>1)&0x55555555));
  60     u = ((u&0x33333333) + ((u>>2)&0x33333333));
  61     u = ((u&0x0f0f0f0f) + ((u>>4)&0x0f0f0f0f));
  62     u = ((u&0x00ff00ff) + ((u>>8)&0x00ff00ff));
  63     u = ( u&0x0000ffff) + (u>>16);
  64     return u;
  65 }
  66
  67 inline uint32_t lsbindex (uint32_t u)
  68 {
  69     return popcount ((u&-u)-1);
  70 }
  71
  72 int audio_get_conf_int (const char *key, int defval)
  73 {
  74     int val = defval;
  75     char *strval;
  76
  77     strval = getenv (key);
  78     if (strval) {
  79         val = atoi (strval);
  80     }
  81
  82     return val;
  83 }
  84
  85 const char *audio_get_conf_str (const char *key, const char *defval)
  86 {
  87     const char *val = getenv (key);
  88     if (!val)
  89         return defval;
  90     else
  91         return val;
  92 }
  93
  94 void AUD_log (const char *cap, const char *fmt, ...)
  95 {
  96     va_list ap;
  97     fprintf (stderr, "%s: ", cap);
  98     va_start (ap, fmt);
  99     vfprintf (stderr, fmt, ap);
 100     va_end (ap);
 101 }
 102
 103 /*
 104  * Soft Voice
 105  */
 106 void pcm_sw_free_resources (SWVoice *sw)
 107 {
 108     if (sw->buf) qemu_free (sw->buf);
 109     if (sw->rate) st_rate_stop (sw->rate);
 110     sw->buf = NULL;
 111     sw->rate = NULL;
 112 }
 113
 114 int pcm_sw_alloc_resources (SWVoice *sw)
 115 {
 116     sw->buf = qemu_mallocz (sw->hw->samples * sizeof (st_sample_t));
 117     if (!sw->buf)
 118         return -1;
 119
 120     sw->rate = st_rate_start (sw->freq, sw->hw->freq);
 121     if (!sw->rate) {
 122         qemu_free (sw->buf);
 123         sw->buf = NULL;
 124         return -1;
 125     }
 126     return 0;
 127 }
 128
 129 void pcm_sw_fini (SWVoice *sw)
 130 {
 131     pcm_sw_free_resources (sw);
 132 }
 133
 134 int pcm_sw_init (SWVoice *sw, HWVoice *hw, int freq,
 135                  int nchannels, audfmt_e fmt)
 136 {
 137     int bits = 8, sign = 0;
 138
 139     switch (fmt) {
 140     case AUD_FMT_S8:
 141         sign = 1;
 142     case AUD_FMT_U8:
 143         break;
 144
 145     case AUD_FMT_S16:
 146         sign = 1;
 147     case AUD_FMT_U16:
 148         bits = 16;
 149         break;
 150     }
 151
 152     sw->hw = hw;
 153     sw->freq = freq;
 154     sw->fmt = fmt;
 155     sw->nchannels = nchannels;
 156     sw->shift = (nchannels == 2) + (bits == 16);
 157     sw->align = (1 << sw->shift) - 1;
 158     sw->left = 0;
 159     sw->pos = 0;
 160     sw->wpos = 0;
 161     sw->live = 0;
 162     sw->ratio = (sw->hw->freq * ((int64_t) INT_MAX)) / sw->freq;
 163     sw->bytes_per_second = sw->freq << sw->shift;
 164     sw->conv = mixeng_conv[nchannels == 2][sign][bits == 16];
 165
 166     pcm_sw_free_resources (sw);
 167     return pcm_sw_alloc_resources (sw);
 168 }
 169
 170 /* Hard voice */
 171 void pcm_hw_free_resources (HWVoice *hw)
 172 {
 173     if (hw->mix_buf)
 174         qemu_free (hw->mix_buf);
 175     hw->mix_buf = NULL;
 176 }
 177
 178 int pcm_hw_alloc_resources (HWVoice *hw)
 179 {
 180     hw->mix_buf = qemu_mallocz (hw->samples * sizeof (st_sample_t));
 181     if (!hw->mix_buf)
 182         return -1;
 183     return 0;
 184 }
 185
 186 void pcm_hw_fini (HWVoice *hw)
 187 {
 188     if (hw->active) {
 189         ldebug ("pcm_hw_fini: %d %d %d\n", hw->freq, hw->nchannels, hw->fmt);
 190         pcm_hw_free_resources (hw);
 191         hw->pcm_ops->fini (hw);
 192         memset (hw, 0, audio_state.drv->voice_size);
 193     }
 194 }
 195
 196 void pcm_hw_gc (HWVoice *hw)
 197 {
 198     if (hw->nb_voices)
 199         return;
 200
 201     pcm_hw_fini (hw);
 202 }
 203
 204 int pcm_hw_get_live (HWVoice *hw)
 205 {
 206     int i, alive = 0, live = hw->samples;
 207
 208     for (i = 0; i < hw->nb_voices; i++) {
 209         if (hw->pvoice[i]->live) {
 210             live = audio_MIN (hw->pvoice[i]->live, live);
 211             alive += 1;
 212         }
 213     }
 214
 215     if (alive)
 216         return live;
 217     else
 218         return -1;
 219 }
 220
 221 int pcm_hw_get_live2 (HWVoice *hw, int *nb_active)
 222 {
 223     int i, alive = 0, live = hw->samples;
 224
 225     *nb_active = 0;
 226     for (i = 0; i < hw->nb_voices; i++) {
 227         if (hw->pvoice[i]->live) {
 228             if (hw->pvoice[i]->live < live) {
 229                 *nb_active = hw->pvoice[i]->active != 0;
 230                 live = hw->pvoice[i]->live;
 231             }
 232             alive += 1;
 233         }
 234     }
 235
 236     if (alive)
 237         return live;
 238     else
 239         return -1;
 240 }
 241
 242 void pcm_hw_dec_live (HWVoice *hw, int decr)
 243 {
 244     int i;
 245
 246     for (i = 0; i < hw->nb_voices; i++) {
 247         if (hw->pvoice[i]->live) {
 248             hw->pvoice[i]->live -= decr;
 249         }
 250     }
 251 }
 252
 253 void pcm_hw_clear (HWVoice *hw, void *buf, int len)
 254 {
 255     if (!len)
 256         return;
 257
 258     switch (hw->fmt) {
 259     case AUD_FMT_S16:
 260     case AUD_FMT_S8:
 261         memset (buf, len << hw->shift, 0x00);
 262         break;
 263
 264     case AUD_FMT_U8:
 265         memset (buf, len << hw->shift, 0x80);
 266         break;
 267
 268     case AUD_FMT_U16:
 269         {
 270             unsigned int i;
 271             uint16_t *p = buf;
 272             int shift = hw->nchannels - 1;
 273
 274             for (i = 0; i < len << shift; i++) {
 275                 p[i] = INT16_MAX;
 276             }
 277         }
 278         break;
 279     }
 280 }
 281
 282 int pcm_hw_write (SWVoice *sw, void *buf, int size)
 283 {
 284     int hwsamples, samples, isamp, osamp, wpos, live, dead, left, swlim, blck;
 285     int ret = 0, pos = 0;
 286     if (!sw)
 287         return size;
 288
 289     hwsamples = sw->hw->samples;
 290     samples = size >> sw->shift;
 291
 292     if (!sw->live) {
 293         sw->wpos = sw->hw->rpos;
 294     }
 295     wpos = sw->wpos;
 296     live = sw->live;
 297     dead = hwsamples - live;
 298     swlim = (dead * ((int64_t) INT_MAX)) / sw->ratio;
 299     swlim = audio_MIN (swlim, samples);
 300
 301     ldebug ("size=%d live=%d dead=%d swlim=%d wpos=%d\n",
 302            size, live, dead, swlim, wpos);
 303     if (swlim)
 304         sw->conv (sw->buf, buf, swlim);
 305
 306     while (swlim) {
 307         dead = hwsamples - live;
 308         left = hwsamples - wpos;
 309         blck = audio_MIN (dead, left);
 310         if (!blck) {
 311             /* dolog ("swlim=%d\n", swlim); */
 312             break;
 313         }
 314         isamp = swlim;
 315         osamp = blck;
 316         st_rate_flow (sw->rate, sw->buf + pos, sw->hw->mix_buf + wpos, &isamp, &osamp);
 317         ret += isamp;
 318         swlim -= isamp;
 319         pos += isamp;
 320         live += osamp;
 321         wpos = (wpos + osamp) % hwsamples;
 322     }
 323
 324     sw->wpos = wpos;
 325     sw->live = live;
 326     return ret << sw->shift;
 327 }
 328
 329 int pcm_hw_init (HWVoice *hw, int freq, int nchannels, audfmt_e fmt)
 330 {
 331     int sign = 0, bits = 8;
 332
 333     pcm_hw_fini (hw);
 334     ldebug ("pcm_hw_init: %d %d %d\n", freq, nchannels, fmt);
 335     if (hw->pcm_ops->init (hw, freq, nchannels, fmt)) {
 336         memset (hw, 0, audio_state.drv->voice_size);
 337         return -1;
 338     }
 339
 340     switch (hw->fmt) {
 341     case AUD_FMT_S8:
 342         sign = 1;
 343     case AUD_FMT_U8:
 344         break;
 345
 346     case AUD_FMT_S16:
 347         sign = 1;
 348     case AUD_FMT_U16:
 349         bits = 16;
 350         break;
 351     }
 352
 353     hw->nb_voices = 0;
 354     hw->active = 1;
 355     hw->shift = (hw->nchannels == 2) + (bits == 16);
 356     hw->bytes_per_second = hw->freq << hw->shift;
 357     hw->align = (1 << hw->shift) - 1;
 358     hw->samples = hw->bufsize >> hw->shift;
 359     hw->clip = mixeng_clip[hw->nchannels == 2][sign][bits == 16];
 360     if (pcm_hw_alloc_resources (hw)) {
 361         pcm_hw_fini (hw);
 362         return -1;
 363     }
 364     return 0;
 365 }
 366
 367 static int dist (void *hw)
 368 {
 369     if (hw) {
 370         return (((uint8_t *) hw - (uint8_t *) hw_voices)
 371                 / audio_state.voice_size) + 1;
 372     }
 373     else {
 374         return 0;
 375     }
 376 }
 377
 378 #define ADVANCE(hw) hw ? advance (hw, audio_state.voice_size) : hw_voices
 379
 380 HWVoice *pcm_hw_find_any (HWVoice *hw)
 381 {
 382     int i = dist (hw);
 383     for (; i < audio_state.nb_hw_voices; i++) {
 384         hw = ADVANCE (hw);
 385         return hw;
 386     }
 387     return NULL;
 388 }
 389
 390 HWVoice *pcm_hw_find_any_active (HWVoice *hw)
 391 {
 392     int i = dist (hw);
 393     for (; i < audio_state.nb_hw_voices; i++) {
 394         hw = ADVANCE (hw);
 395         if (hw->active)
 396             return hw;
 397     }
 398     return NULL;
 399 }
 400
 401 HWVoice *pcm_hw_find_any_active_enabled (HWVoice *hw)
 402 {
 403     int i = dist (hw);
 404     for (; i < audio_state.nb_hw_voices; i++) {
 405         hw = ADVANCE (hw);
 406         if (hw->active && hw->enabled)
 407             return hw;
 408     }
 409     return NULL;
 410 }
 411
 412 HWVoice *pcm_hw_find_any_passive (HWVoice *hw)
 413 {
 414     int i = dist (hw);
 415     for (; i < audio_state.nb_hw_voices; i++) {
 416         hw = ADVANCE (hw);
 417         if (!hw->active)
 418             return hw;
 419     }
 420     return NULL;
 421 }
 422
 423 HWVoice *pcm_hw_find_specific (HWVoice *hw, int freq,
 424                                int nchannels, audfmt_e fmt)
 425 {
 426     while ((hw = pcm_hw_find_any_active (hw))) {
 427         if (hw->freq == freq &&
 428             hw->nchannels == nchannels &&
 429             hw->fmt == fmt)
 430             return hw;
 431     }
 432     return NULL;
 433 }
 434
 435 HWVoice *pcm_hw_add (int freq, int nchannels, audfmt_e fmt)
 436 {
 437     HWVoice *hw;
 438
 439     if (audio_state.fixed_format) {
 440         freq = audio_state.fixed_freq;
 441         nchannels = audio_state.fixed_channels;
 442         fmt = audio_state.fixed_fmt;
 443     }
 444
 445     hw = pcm_hw_find_specific (NULL, freq, nchannels, fmt);
 446
 447     if (hw)
 448         return hw;
 449
 450     hw = pcm_hw_find_any_passive (NULL);
 451     if (hw) {
 452         hw->pcm_ops = audio_state.drv->pcm_ops;
 453         if (!hw->pcm_ops)
 454             return NULL;
 455
 456         if (pcm_hw_init (hw, freq, nchannels, fmt)) {
 457             pcm_hw_gc (hw);
 458             return NULL;
 459         }
 460         else
 461             return hw;
 462     }
 463
 464     return pcm_hw_find_any (NULL);
 465 }
 466
 467 int pcm_hw_add_sw (HWVoice *hw, SWVoice *sw)
 468 {
 469     SWVoice **pvoice = qemu_mallocz ((hw->nb_voices + 1) * sizeof (sw));
 470     if (!pvoice)
 471         return -1;
 472
 473     memcpy (pvoice, hw->pvoice, hw->nb_voices * sizeof (sw));
 474     qemu_free (hw->pvoice);
 475     hw->pvoice = pvoice;
 476     hw->pvoice[hw->nb_voices++] = sw;
 477     return 0;
 478 }
 479
 480 int pcm_hw_del_sw (HWVoice *hw, SWVoice *sw)
 481 {
 482     int i, j;
 483     if (hw->nb_voices > 1) {
 484         SWVoice **pvoice = qemu_mallocz ((hw->nb_voices - 1) * sizeof (sw));
 485
 486         if (!pvoice) {
 487             dolog ("Can not maintain consistent state (not enough memory)\n");
 488             return -1;
 489         }
 490
 491         for (i = 0, j = 0; i < hw->nb_voices; i++) {
 492             if (j >= hw->nb_voices - 1) {
 493                 dolog ("Can not maintain consistent state "
 494                        "(invariant violated)\n");
 495                 return -1;
 496             }
 497             if (hw->pvoice[i] != sw)
 498                 pvoice[j++] = hw->pvoice[i];
 499         }
 500         qemu_free (hw->pvoice);
 501         hw->pvoice = pvoice;
 502         hw->nb_voices -= 1;
 503     }
 504     else {
 505         qemu_free (hw->pvoice);
 506         hw->pvoice = NULL;
 507         hw->nb_voices = 0;
 508     }
 509     return 0;
 510 }
 511
 512 SWVoice *pcm_create_voice_pair (int freq, int nchannels, audfmt_e fmt)
 513 {
 514     SWVoice *sw;
 515     HWVoice *hw;
 516
 517     sw = qemu_mallocz (sizeof (*sw));
 518     if (!sw)
 519         goto err1;
 520
 521     hw = pcm_hw_add (freq, nchannels, fmt);
 522     if (!hw)
 523         goto err2;
 524
 525     if (pcm_hw_add_sw (hw, sw))
 526         goto err3;
 527
 528     if (pcm_sw_init (sw, hw, freq, nchannels, fmt))
 529         goto err4;
 530
 531     return sw;
 532
 533 err4:
 534     pcm_hw_del_sw (hw, sw);
 535 err3:
 536     pcm_hw_gc (hw);
 537 err2:
 538     qemu_free (sw);
 539 err1:
 540     return NULL;
 541 }
 542
 543 SWVoice *AUD_open (SWVoice *sw, const char *name,
 544                    int freq, int nchannels, audfmt_e fmt)
 545 {
 546     if (!audio_state.drv) {
 547         return NULL;
 548     }
 549
 550     if (sw && freq == sw->freq && sw->nchannels == nchannels && sw->fmt == fmt) {
 551         return sw;
 552     }
 553
 554     if (sw) {
 555         ldebug ("Different format %s %d %d %d\n",
 556                 name,
 557                 sw->freq == freq,
 558                 sw->nchannels == nchannels,
 559                 sw->fmt == fmt);
 560     }
 561
 562     if (nchannels != 1 && nchannels != 2) {
 563         dolog ("Bogus channel count %d for voice %s\n", nchannels, name);
 564         return NULL;
 565     }
 566
 567     if (!audio_state.fixed_format && sw) {
 568         pcm_sw_fini (sw);
 569         pcm_hw_del_sw (sw->hw, sw);
 570         pcm_hw_gc (sw->hw);
 571         if (sw->name) {
 572             qemu_free (sw->name);
 573             sw->name = NULL;
 574         }
 575         qemu_free (sw);
 576         sw = NULL;
 577     }
 578
 579     if (sw) {
 580         HWVoice *hw = sw->hw;
 581         if (!hw) {
 582             dolog ("Internal logic error voice %s has no hardware store\n",
 583                    name);
 584             return sw;
 585         }
 586
 587         if (pcm_sw_init (sw, hw, freq, nchannels, fmt)) {
 588             pcm_sw_fini (sw);
 589             pcm_hw_del_sw (hw, sw);
 590             pcm_hw_gc (hw);
 591             if (sw->name) {
 592                 qemu_free (sw->name);
 593                 sw->name = NULL;
 594             }
 595             qemu_free (sw);
 596             return NULL;
 597         }
 598     }
 599     else {
 600         sw = pcm_create_voice_pair (freq, nchannels, fmt);
 601         if (!sw) {
 602             dolog ("Failed to create voice %s\n", name);
 603             return NULL;
 604         }
 605     }
 606
 607     if (sw->name) {
 608         qemu_free (sw->name);
 609         sw->name = NULL;
 610     }
 611     sw->name = qemu_strdup (name);
 612     return sw;
 613 }
 614
 615 void AUD_close (SWVoice *sw)
 616 {
 617     if (!sw)
 618         return;
 619
 620     pcm_sw_fini (sw);
 621     pcm_hw_del_sw (sw->hw, sw);
 622     pcm_hw_gc (sw->hw);
 623     if (sw->name) {
 624         qemu_free (sw->name);
 625         sw->name = NULL;
 626     }
 627     qemu_free (sw);
 628 }
 629
 630 int AUD_write (SWVoice *sw, void *buf, int size)
 631 {
 632     int bytes;
 633
 634     if (!sw->hw->enabled)
 635         dolog ("Writing to disabled voice %s\n", sw->name);
 636     bytes = sw->hw->pcm_ops->write (sw, buf, size);
 637     return bytes;
 638 }
 639
 640 void AUD_run (void)
 641 {
 642     HWVoice *hw = NULL;
 643
 644     while ((hw = pcm_hw_find_any_active_enabled (hw))) {
 645         int i;
 646         if (hw->pending_disable && pcm_hw_get_live (hw) <= 0) {
 647             hw->enabled = 0;
 648             hw->pcm_ops->ctl (hw, VOICE_DISABLE);
 649             for (i = 0; i < hw->nb_voices; i++) {
 650                 hw->pvoice[i]->live = 0;
 651                 /* hw->pvoice[i]->old_ticks = 0; */
 652             }
 653             continue;
 654         }
 655
 656         hw->pcm_ops->run (hw);
 657         assert (hw->rpos < hw->samples);
 658         for (i = 0; i < hw->nb_voices; i++) {
 659             SWVoice *sw = hw->pvoice[i];
 660             if (!sw->active && !sw->live && sw->old_ticks) {
 661                 int64_t delta = qemu_get_clock (vm_clock) - sw->old_ticks;
 662                 if (delta > audio_state.ticks_threshold) {
 663                     ldebug ("resetting old_ticks for %s\n", sw->name);
 664                     sw->old_ticks = 0;
 665                 }
 666             }
 667         }
 668     }
 669 }
 670
 671 int AUD_get_free (SWVoice *sw)
 672 {
 673     int free;
 674
 675     if (!sw)
 676         return 4096;
 677
 678     free = ((sw->hw->samples - sw->live) << sw->hw->shift) * sw->ratio
 679         / INT_MAX;
 680
 681     free &= ~sw->hw->align;
 682     if (!free) return 0;
 683
 684     return free;
 685 }
 686
 687 int AUD_get_buffer_size (SWVoice *sw)
 688 {
 689     return sw->hw->bufsize;
 690 }
 691
 692 void AUD_adjust (SWVoice *sw, int bytes)
 693 {
 694     if (!sw)
 695         return;
 696     sw->old_ticks += (ticks_per_sec * (int64_t) bytes) / sw->bytes_per_second;
 697 }
 698
 699 void AUD_reset (SWVoice *sw)
 700 {
 701     sw->active = 0;
 702     sw->old_ticks = 0;
 703 }
 704
 705 int AUD_calc_elapsed (SWVoice *sw)
 706 {
 707     int64_t now, delta, bytes;
 708     int dead, swlim;
 709
 710     if (!sw)
 711         return 0;
 712
 713     now = qemu_get_clock (vm_clock);
 714     delta = now - sw->old_ticks;
 715     bytes = (delta * sw->bytes_per_second) / ticks_per_sec;
 716     if (delta < 0) {
 717         dolog ("whoops delta(<0)=%lld\n", delta);
 718         return 0;
 719     }
 720
 721     dead = sw->hw->samples - sw->live;
 722     swlim = ((dead * (int64_t) INT_MAX) / sw->ratio);
 723
 724     if (bytes > swlim) {
 725         return swlim;
 726     }
 727     else {
 728         return bytes;
 729     }
 730 }
 731
 732 void AUD_enable (SWVoice *sw, int on)
 733 {
 734     int i;
 735     HWVoice *hw;
 736
 737     if (!sw)
 738         return;
 739
 740     hw = sw->hw;
 741     if (on) {
 742         if (!sw->live)
 743             sw->wpos = sw->hw->rpos;
 744         if (!sw->old_ticks) {
 745             sw->old_ticks = qemu_get_clock (vm_clock);
 746         }
 747     }
 748
 749     if (sw->active != on) {
 750         if (on) {
 751             hw->pending_disable = 0;
 752             if (!hw->enabled) {
 753                 hw->enabled = 1;
 754                 for (i = 0; i < hw->nb_voices; i++) {
 755                     ldebug ("resetting voice\n");
 756                     sw = hw->pvoice[i];
 757                     sw->old_ticks = qemu_get_clock (vm_clock);
 758                 }
 759                 hw->pcm_ops->ctl (hw, VOICE_ENABLE);
 760             }
 761         }
 762         else {
 763             if (hw->enabled && !hw->pending_disable) {
 764                 int nb_active = 0;
 765                 for (i = 0; i < hw->nb_voices; i++) {
 766                     nb_active += hw->pvoice[i]->active != 0;
 767                 }
 768
 769                 if (nb_active == 1) {
 770                     hw->pending_disable = 1;
 771                 }
 772             }
 773         }
 774         sw->active = on;
 775     }
 776 }
 777
 778 static struct audio_output_driver *drvtab[] = {
 779 #ifdef CONFIG_OSS
 780     &oss_output_driver,
 781 #endif
 782 #ifdef USE_FMOD_AUDIO
 783     &fmod_output_driver,
 784 #endif
 785 #ifdef CONFIG_SDL
 786     &sdl_output_driver,
 787 #endif
 788     &no_output_driver,
 789 #ifdef USE_WAV_AUDIO
 790     &wav_output_driver,
 791 #endif
 792 };
 793
 794 static int voice_init (struct audio_output_driver *drv)
 795 {
 796     audio_state.opaque = drv->init ();
 797     if (audio_state.opaque) {
 798         if (audio_state.nb_hw_voices > drv->max_voices) {
 799             dolog ("`%s' does not support %d multiple hardware channels\n"
 800                    "Resetting to %d\n",
 801                    drv->name, audio_state.nb_hw_voices, drv->max_voices);
 802             audio_state.nb_hw_voices = drv->max_voices;
 803         }
 804         hw_voices = qemu_mallocz (audio_state.nb_hw_voices * drv->voice_size);
 805         if (hw_voices) {
 806             audio_state.drv = drv;
 807             return 1;
 808         }
 809         else {
 810             dolog ("Not enough memory for %d `%s' voices (each %d bytes)\n",
 811                    audio_state.nb_hw_voices, drv->name, drv->voice_size);
 812             drv->fini (audio_state.opaque);
 813             return 0;
 814         }
 815     }
 816     else {
 817         dolog ("Could not init `%s' audio\n", drv->name);
 818         return 0;
 819     }
 820 }
 821
 822 static void audio_vm_stop_handler (void *opaque, int reason)
 823 {
 824     HWVoice *hw = NULL;
 825
 826     while ((hw = pcm_hw_find_any (hw))) {
 827         if (!hw->pcm_ops)
 828             continue;
 829
 830         hw->pcm_ops->ctl (hw, reason ? VOICE_ENABLE : VOICE_DISABLE);
 831     }
 832 }
 833
 834 static void audio_atexit (void)
 835 {
 836     HWVoice *hw = NULL;
 837
 838     while ((hw = pcm_hw_find_any (hw))) {
 839         if (!hw->pcm_ops)
 840             continue;
 841
 842         hw->pcm_ops->ctl (hw, VOICE_DISABLE);
 843         hw->pcm_ops->fini (hw);
 844     }
 845     audio_state.drv->fini (audio_state.opaque);
 846 }
 847
 848 static void audio_save (QEMUFile *f, void *opaque)
 849 {
 850 }
 851
 852 static int audio_load (QEMUFile *f, void *opaque, int version_id)
 853 {
 854     if (version_id != 1)
 855         return -EINVAL;
 856
 857     return 0;
 858 }
 859
 860 void AUD_init (void)
 861 {
 862     int i;
 863     int done = 0;
 864     const char *drvname;
 865
 866     audio_state.fixed_format =
 867         !!audio_get_conf_int (QC_FIXED_FORMAT, audio_state.fixed_format);
 868     audio_state.fixed_freq =
 869         audio_get_conf_int (QC_FIXED_FREQ, audio_state.fixed_freq);
 870     audio_state.nb_hw_voices =
 871         audio_get_conf_int (QC_VOICES, audio_state.nb_hw_voices);
 872
 873     if (audio_state.nb_hw_voices <= 0) {
 874         dolog ("Bogus number of voices %d, resetting to 1\n",
 875                audio_state.nb_hw_voices);
 876     }
 877
 878     drvname = audio_get_conf_str (QC_AUDIO_DRV, NULL);
 879     if (drvname) {
 880         int found = 0;
 881         for (i = 0; i < sizeof (drvtab) / sizeof (drvtab[0]); i++) {
 882             if (!strcmp (drvname, drvtab[i]->name)) {
 883                 done = voice_init (drvtab[i]);
 884                 found = 1;
 885                 break;
 886             }
 887         }
 888         if (!found) {
 889             dolog ("Unknown audio driver `%s'\n", drvname);
 890         }
 891     }
 892
 893     qemu_add_vm_stop_handler (audio_vm_stop_handler, NULL);
 894     atexit (audio_atexit);
 895
 896     if (!done) {
 897         for (i = 0; !done && i < sizeof (drvtab) / sizeof (drvtab[0]); i++) {
 898             if (drvtab[i]->can_be_default)
 899                 done = voice_init (drvtab[i]);
 900         }
 901     }
 902
 903     audio_state.ticks_threshold = ticks_per_sec / 50;
 904     audio_state.freq_threshold = 100;
 905
 906     register_savevm ("audio", 0, 1, audio_save, audio_load, NULL);
 907     if (!done) {
 908         dolog ("Can not initialize audio subsystem\n");
 909         voice_init (&no_output_driver);
 910     }
 911 }