oss.c

   1 /*
   2  * QEMU OSS Audio output driver
   3  *
   4  * Copyright (c) 2003 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 "vl.h"
  25
  26 #ifndef _WIN32
  27 #include <ctype.h>
  28 #include <fcntl.h>
  29 #include <errno.h>
  30 #include <stdio.h>
  31 #include <unistd.h>
  32 #include <string.h>
  33 #include <stdlib.h>
  34 #include <limits.h>
  35 #include <inttypes.h>
  36 #include <sys/mman.h>
  37 #include <sys/types.h>
  38 #include <sys/ioctl.h>
  39 #include <sys/soundcard.h>
  40
  41
  42 /* http://www.df.lth.se/~john_e/gems/gem002d.html */
  43 /* http://www.multi-platforms.com/Tips/PopCount.htm */
  44 static inline uint32_t popcount (uint32_t u)
  45 {
  46   u = ((u&0x55555555) + ((u>>1)&0x55555555));
  47   u = ((u&0x33333333) + ((u>>2)&0x33333333));
  48   u = ((u&0x0f0f0f0f) + ((u>>4)&0x0f0f0f0f));
  49   u = ((u&0x00ff00ff) + ((u>>8)&0x00ff00ff));
  50   u = ( u&0x0000ffff) + (u>>16);
  51   return u;
  52 }
  53
  54 static inline uint32_t lsbindex (uint32_t u)
  55 {
  56   return popcount ((u&-u)-1);
  57 }
  58
  59 #define MIN(a, b) ((a)>(b)?(b):(a))
  60 #define MAX(a, b) ((a)<(b)?(b):(a))
  61
  62 #define DEREF(x) (void)x
  63 #define log(...) fprintf (stderr, "oss: " __VA_ARGS__)
  64 #define ERRFail(...) do {                                       \
  65     int _errno = errno;                                         \
  66     fprintf (stderr, "oss: " __VA_ARGS__);                      \
  67     fprintf (stderr, "system error: %s\n", strerror (_errno));  \
  68     abort ();                                                   \
  69 } while (0)
  70 #define Fail(...) do {                          \
  71     fprintf (stderr, "oss: " __VA_ARGS__);      \
  72     fprintf (stderr, "\n");                     \
  73     abort ();                                   \
  74 } while (0)
  75
  76 #ifdef DEBUG_OSS
  77 #define lwarn(...) fprintf (stderr, "oss: " __VA_ARGS__)
  78 #define linfo(...) fprintf (stderr, "oss: " __VA_ARGS__)
  79 #define ldebug(...) fprintf (stderr, "oss: " __VA_ARGS__)
  80 #else
  81 #define lwarn(...)
  82 #define linfo(...)
  83 #define ldebug(...)
  84 #endif
  85
  86
  87 #define IOCTL(args) do {                        \
  88   int ret = ioctl args;                         \
  89   if (-1 == ret) {                              \
  90     ERRFail (#args);                            \
  91   }                                             \
  92   ldebug ("ioctl " #args " = %d\n", ret);       \
  93 } while (0)
  94
  95 static struct {
  96     int fd;
  97     int freq;
  98     int bits16;
  99     int nchannels;
 100     int rpos;
 101     int wpos;
 102     int live;
 103     int oss_fmt;
 104     int bytes_per_second;
 105     int is_mapped;
 106     void *buf;
 107     int bufsize;
 108     int nfrags;
 109     int fragsize;
 110     int old_optr;
 111     int leftover;
 112     uint64_t old_ticks;
 113     void (*copy_fn)(void *, void *, int);
 114 } oss = { .fd = -1 };
 115
 116 static struct {
 117     int try_mmap;
 118     int nfrags;
 119     int fragsize;
 120 } conf = {
 121     .try_mmap = 0,
 122     .nfrags = 4,
 123     .fragsize = 4096
 124 };
 125
 126 static enum {DONT, DSP, TID} est = DONT;
 127
 128 static void copy_no_conversion (void *dst, void *src, int size)
 129 {
 130     memcpy (dst, src, size);
 131 }
 132
 133 static void copy_u16_to_s16 (void *dst, void *src, int size)
 134 {
 135     int i;
 136     uint16_t *out, *in;
 137
 138     out = dst;
 139     in = src;
 140
 141     for (i = 0; i < size / 2; i++) {
 142         out[i] = in[i] + 0x8000;
 143     }
 144 }
 145
 146 static void pab (struct audio_buf_info *abinfo)
 147 {
 148     DEREF (abinfo);
 149
 150     ldebug ("fragments %d, fragstotal %d, fragsize %d, bytes %d\n"
 151             "rpos %d, wpos %d, live %d\n",
 152             abinfo->fragments,
 153             abinfo->fragstotal,
 154             abinfo->fragsize,
 155             abinfo->bytes,
 156             rpos, wpos, live);
 157 }
 158
 159 static void do_open ()
 160 {
 161     int mmmmssss;
 162     audio_buf_info abinfo;
 163     int fmt, freq, nchannels;
 164
 165     if (oss.buf) {
 166         if (-1 == munmap (oss.buf, oss.bufsize)) {
 167             ERRFail ("failed to unmap audio buffer %p %d",
 168                      oss.buf, oss.bufsize);
 169         }
 170         oss.buf = NULL;
 171     }
 172
 173     if (-1 != oss.fd)
 174         close (oss.fd);
 175
 176     oss.fd = open ("/dev/dsp", O_RDWR | O_NONBLOCK);
 177     if (-1 == oss.fd) {
 178         ERRFail ("can not open /dev/dsp");
 179     }
 180
 181     fmt = oss.oss_fmt;
 182     freq = oss.freq;
 183     nchannels = oss.nchannels;
 184
 185     IOCTL ((oss.fd, SNDCTL_DSP_RESET, 1));
 186     IOCTL ((oss.fd, SNDCTL_DSP_SAMPLESIZE, &fmt));
 187     IOCTL ((oss.fd, SNDCTL_DSP_CHANNELS, &nchannels));
 188     IOCTL ((oss.fd, SNDCTL_DSP_SPEED, &freq));
 189     IOCTL ((oss.fd, SNDCTL_DSP_NONBLOCK));
 190
 191     mmmmssss = (conf.nfrags << 16) | conf.fragsize;
 192     IOCTL ((oss.fd, SNDCTL_DSP_SETFRAGMENT, &mmmmssss));
 193
 194     if ((oss.oss_fmt != fmt)
 195         || (oss.nchannels != nchannels)
 196         || (oss.freq != freq)) {
 197         Fail ("failed to set audio parameters\n"
 198               "parameter | requested value | obtained value\n"
 199               "format    |      %10d |     %10d\n"
 200               "channels  |      %10d |     %10d\n"
 201               "frequency |      %10d |     %10d\n",
 202               oss.oss_fmt, fmt,
 203               oss.nchannels, nchannels,
 204               oss.freq, freq);
 205     }
 206
 207     IOCTL ((oss.fd, SNDCTL_DSP_GETOSPACE, &abinfo));
 208
 209     oss.nfrags = abinfo.fragstotal;
 210     oss.fragsize = abinfo.fragsize;
 211     oss.bufsize = oss.nfrags * oss.fragsize;
 212     oss.old_optr = 0;
 213
 214     oss.bytes_per_second = (freq << (nchannels >> 1)) << oss.bits16;
 215
 216     linfo ("bytes per second %d\n", oss.bytes_per_second);
 217
 218     linfo ("fragments %d, fragstotal %d, fragsize %d, bytes %d, bufsize %d\n",
 219            abinfo.fragments,
 220            abinfo.fragstotal,
 221            abinfo.fragsize,
 222            abinfo.bytes,
 223            oss.bufsize);
 224
 225     oss.buf = MAP_FAILED;
 226     oss.is_mapped = 0;
 227
 228     if (conf.try_mmap) {
 229         oss.buf = mmap (NULL, oss.bufsize, PROT_WRITE, MAP_SHARED, oss.fd, 0);
 230         if (MAP_FAILED == oss.buf) {
 231             int err;
 232
 233             err = errno;
 234             log ("failed to mmap audio, size %d, fd %d\n"
 235                  "syserr: %s\n",
 236                  oss.bufsize, oss.fd, strerror (err));
 237         }
 238     else {
 239             est = TID;
 240             oss.is_mapped = 1;
 241         }
 242     }
 243
 244     if (MAP_FAILED == oss.buf) {
 245         est = TID;
 246         oss.buf = mmap (NULL, oss.bufsize, PROT_READ | PROT_WRITE,
 247                         MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
 248         if (MAP_FAILED == oss.buf) {
 249             ERRFail ("mmap audio buf, size %d", oss.bufsize);
 250         }
 251     }
 252
 253     oss.rpos = 0;
 254     oss.wpos = 0;
 255     oss.live = 0;
 256
 257     if (oss.is_mapped) {
 258         int trig;
 259
 260         trig = 0;
 261         IOCTL ((oss.fd, SNDCTL_DSP_SETTRIGGER, &trig));
 262         trig = PCM_ENABLE_OUTPUT;
 263         IOCTL ((oss.fd, SNDCTL_DSP_SETTRIGGER, &trig));
 264     }
 265 }
 266
 267 static void maybe_open (int req_freq, int req_nchannels,
 268                         audfmt_e req_fmt, int force_open)
 269 {
 270     int oss_fmt, bits16;
 271
 272     switch (req_fmt) {
 273     case AUD_FMT_U8:
 274         bits16 = 0;
 275         oss_fmt = AFMT_U8;
 276         oss.copy_fn = copy_no_conversion;
 277         break;
 278
 279     case AUD_FMT_S8:
 280         Fail ("can not play 8bit signed");
 281
 282     case AUD_FMT_S16:
 283         bits16 = 1;
 284         oss_fmt = AFMT_S16_LE;
 285         oss.copy_fn = copy_no_conversion;
 286         break;
 287
 288     case AUD_FMT_U16:
 289         bits16 = 1;
 290         oss_fmt = AFMT_S16_LE;
 291         oss.copy_fn = copy_u16_to_s16;
 292         break;
 293
 294     default:
 295         abort ();
 296     }
 297
 298     if (force_open
 299         || (-1 == oss.fd)
 300         || (oss_fmt != oss.oss_fmt)
 301         || (req_nchannels != oss.nchannels)
 302         || (req_freq != oss.freq)
 303         || (bits16 != oss.bits16)) {
 304         oss.oss_fmt = oss_fmt;
 305         oss.nchannels = req_nchannels;
 306         oss.freq = req_freq;
 307         oss.bits16 = bits16;
 308         do_open ();
 309     }
 310 }
 311
 312 void AUD_reset (int req_freq, int req_nchannels, audfmt_e req_fmt)
 313 {
 314     maybe_open (req_freq, req_nchannels, req_fmt, 0);
 315 }
 316
 317 void AUD_open (int req_freq, int req_nchannels, audfmt_e req_fmt)
 318 {
 319     maybe_open (req_freq, req_nchannels, req_fmt, 1);
 320 }
 321
 322 int AUD_write (void *in_buf, int size)
 323 {
 324     int to_copy, temp;
 325     uint8_t *in, *out;
 326
 327     to_copy = MIN (oss.bufsize - oss.live, size);
 328
 329     temp = to_copy;
 330
 331     in = in_buf;
 332     out = oss.buf;
 333
 334     while (temp) {
 335         int copy;
 336
 337         copy = MIN (temp, oss.bufsize - oss.wpos);
 338         oss.copy_fn (out + oss.wpos, in, copy);
 339
 340         oss.wpos += copy;
 341         if (oss.wpos == oss.bufsize) {
 342             oss.wpos = 0;
 343         }
 344
 345         temp -= copy;
 346         in += copy;
 347         oss.live += copy;
 348     }
 349
 350     return to_copy;
 351 }
 352
 353 void AUD_run (void)
 354 {
 355     int res;
 356     int bytes;
 357     struct audio_buf_info abinfo;
 358
 359     if (0 == oss.live)
 360         return;
 361
 362     if (oss.is_mapped) {
 363         count_info info;
 364
 365         res = ioctl (oss.fd, SNDCTL_DSP_GETOPTR, &info);
 366         if (-1 == res) {
 367             int err;
 368
 369             err = errno;
 370             lwarn ("SNDCTL_DSP_GETOPTR failed with %s\n", strerror (err));
 371             return;
 372         }
 373
 374         if (info.ptr > oss.old_optr) {
 375             bytes = info.ptr - oss.old_optr;
 376         }
 377         else {
 378             bytes = oss.bufsize + info.ptr - oss.old_optr;
 379         }
 380
 381         oss.old_optr = info.ptr;
 382         oss.live -= bytes;
 383         return;
 384     }
 385
 386     res = ioctl (oss.fd, SNDCTL_DSP_GETOSPACE, &abinfo);
 387
 388     if (-1 == res) {
 389         int err;
 390
 391         err = errno;
 392         lwarn ("SNDCTL_DSP_GETOSPACE failed with %s\n", strerror (err));
 393     }
 394
 395     bytes = abinfo.bytes;
 396     bytes = MIN (oss.live, bytes);
 397 #if 0
 398     bytes = (bytes / fragsize) * fragsize;
 399 #endif
 400
 401     while (bytes) {
 402         int left, play, written;
 403
 404         left = oss.bufsize - oss.rpos;
 405         play = MIN (left, bytes);
 406         written = write (oss.fd, (void *) ((uint32_t) oss.buf + oss.rpos), play);
 407
 408         if (-1 == written) {
 409             if (EAGAIN == errno || EINTR == errno) {
 410                 return;
 411             }
 412             else {
 413                 ERRFail ("write audio");
 414             }
 415         }
 416
 417         play = written;
 418         oss.live -= play;
 419         oss.rpos += play;
 420         bytes -= play;
 421
 422         if (oss.rpos == oss.bufsize) {
 423             oss.rpos = 0;
 424         }
 425     }
 426 }
 427
 428 static int get_dsp_bytes (void)
 429 {
 430     int res;
 431     struct count_info info;
 432
 433     res = ioctl (oss.fd, SNDCTL_DSP_GETOPTR, &info);
 434     if (-1 == res) {
 435         int err;
 436
 437         err = errno;
 438         lwarn ("SNDCTL_DSP_GETOPTR failed with %s\n", strerror (err));
 439         return -1;
 440     }
 441     else {
 442         ldebug ("bytes %d\n", info.bytes);
 443         return info.bytes;
 444     }
 445 }
 446
 447 void AUD_adjust_estimate (int leftover)
 448 {
 449     oss.leftover = leftover;
 450 }
 451
 452 int AUD_get_free (void)
 453 {
 454     int free, elapsed;
 455
 456     free = oss.bufsize - oss.live;
 457
 458     if (0 == free)
 459         return 0;
 460
 461     elapsed = free;
 462     switch (est) {
 463     case DONT:
 464         break;
 465
 466     case DSP:
 467         {
 468             static int old_bytes;
 469             int bytes;
 470
 471             bytes = get_dsp_bytes ();
 472             if (bytes <= 0)
 473                 return free;
 474
 475             elapsed = bytes - old_bytes;
 476             old_bytes = bytes;
 477             ldebug ("dsp elapsed %d bytes\n", elapsed);
 478             break;
 479         }
 480
 481     case TID:
 482         {
 483             uint64_t ticks, delta;
 484             uint64_t ua_elapsed;
 485             uint64_t al_elapsed;
 486
 487             ticks = qemu_get_clock(rt_clock);
 488             delta = ticks - oss.old_ticks;
 489             oss.old_ticks = ticks;
 490
 491             ua_elapsed = (delta * oss.bytes_per_second) / 1000;
 492             al_elapsed = ua_elapsed & ~3ULL;
 493
 494             ldebug ("tid elapsed %llu bytes\n", ua_elapsed);
 495
 496             if (al_elapsed > (uint64_t) INT_MAX)
 497                 elapsed = INT_MAX;
 498             else
 499                 elapsed = al_elapsed;
 500
 501             elapsed += oss.leftover;
 502         }
 503     }
 504
 505     if (elapsed > free) {
 506         lwarn ("audio can not keep up elapsed %d free %d\n", elapsed, free);
 507         return free;
 508     }
 509     else {
 510         return elapsed;
 511     }
 512 }
 513
 514 int AUD_get_live (void)
 515 {
 516     return oss.live;
 517 }
 518
 519 int AUD_get_buffer_size (void)
 520 {
 521     return oss.bufsize;
 522 }
 523
 524 #define QC_OSS_FRAGSIZE "QEMU_OSS_FRAGSIZE"
 525 #define QC_OSS_NFRAGS "QEMU_OSS_NFRAGS"
 526 #define QC_OSS_MMAP "QEMU_OSS_MMAP"
 527
 528 static int get_conf_val (const char *key, int defval)
 529 {
 530     int val = defval;
 531     char *strval;
 532
 533     strval = getenv (key);
 534     if (strval) {
 535         val = atoi (strval);
 536     }
 537
 538     return val;
 539 }
 540
 541 void AUD_init (void)
 542 {
 543     int fsp;
 544
 545     DEREF (pab);
 546
 547     conf.fragsize = get_conf_val (QC_OSS_FRAGSIZE, conf.fragsize);
 548     conf.nfrags = get_conf_val (QC_OSS_NFRAGS, conf.nfrags);
 549     conf.try_mmap = get_conf_val (QC_OSS_MMAP, conf.try_mmap);
 550
 551     fsp = conf.fragsize;
 552     if (0 != (fsp & (fsp - 1))) {
 553         Fail ("fragment size %d is not power of 2", fsp);
 554     }
 555
 556     conf.fragsize = lsbindex (fsp);
 557 }
 558
 559 #else
 560
 561 void AUD_run (void)
 562 {
 563 }
 564
 565 int AUD_write (void *in_buf, int size)
 566 {
 567     return 0;
 568 }
 569
 570 void AUD_reset (int rfreq, int rnchannels, audfmt_e rfmt)
 571 {
 572 }
 573
 574 void AUD_adjust_estimate (int _leftover)
 575 {
 576 }
 577
 578 int AUD_get_free (void)
 579 {
 580     return 0;
 581 }
 582
 583 int AUD_get_live (void)
 584 {
 585     return 0;
 586 }
 587
 588 int AUD_get_buffer_size (void)
 589 {
 590     return 0;
 591 }
 592
 593 void AUD_init (void)
 594 {
 595 }
 596
 597 #endif