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