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 <fcntl.h>
  28 #include <errno.h>
  29 #include <stdio.h>
  30 #include <unistd.h>
  31 #include <string.h>
  32 #include <stdlib.h>
  33 #include <limits.h>
  34 #include <inttypes.h>
  35 #include <sys/types.h>
  36 #include <sys/ioctl.h>
  37 #include <sys/soundcard.h>
  38
  39
  40 /* http://www.df.lth.se/~john_e/gems/gem002d.html */
  41 /* http://www.multi-platforms.com/Tips/PopCount.htm */
  42 static inline uint32_t popcount (uint32_t u)
  43 {
  44   u = ((u&0x55555555) + ((u>>1)&0x55555555));
  45   u = ((u&0x33333333) + ((u>>2)&0x33333333));
  46   u = ((u&0x0f0f0f0f) + ((u>>4)&0x0f0f0f0f));
  47   u = ((u&0x00ff00ff) + ((u>>8)&0x00ff00ff));
  48   u = ( u&0x0000ffff) + (u>>16);
  49   return u;
  50 }
  51
  52 static inline uint32_t lsbindex (uint32_t u)
  53 {
  54   return popcount ((u&-u)-1);
  55 }
  56
  57 #define MIN(a, b) ((a)>(b)?(b):(a))
  58 #define MAX(a, b) ((a)<(b)?(b):(a))
  59
  60 #define DEREF(x) (void)x
  61 #define log(...) fprintf (stderr, "oss: " __VA_ARGS__)
  62 #define ERRFail(...) do {                                       \
  63     int _errno = errno;                                         \
  64     fprintf (stderr, "oss: " __VA_ARGS__);                      \
  65     fprintf (stderr, "system error: %s\n", strerror (_errno));  \
  66     abort ();                                                   \
  67 } while (0)
  68 #define Fail(...) do {                          \
  69     fprintf (stderr, "oss: " __VA_ARGS__);      \
  70     fprintf (stderr, "\n");                     \
  71     abort ();                                   \
  72 } while (0)
  73
  74 #ifdef DEBUG_OSS
  75 #define lwarn(...) fprintf (stderr, "oss: " __VA_ARGS__)
  76 #define linfo(...) fprintf (stderr, "oss: " __VA_ARGS__)
  77 #define ldebug(...) fprintf (stderr, "oss: " __VA_ARGS__)
  78 #else
  79 #define lwarn(...)
  80 #define linfo(...)
  81 #define ldebug(...)
  82 #endif
  83
  84
  85 #define IOCTL(args) do {                        \
  86   int ret = ioctl args;                         \
  87   if (-1 == ret) {                              \
  88     ERRFail (#args);                            \
  89   }                                             \
  90   ldebug ("ioctl " #args " = %d\n", ret);       \
  91 } while (0)
  92
  93 static int audio_fd = -1;
  94 static int freq;
  95 static int conf_nfrags = 4;
  96 static int conf_fragsize;
  97 static int nfrags;
  98 static int fragsize;
  99 static int bufsize;
 100 static int nchannels;
 101 static int fmt;
 102 static int rpos;
 103 static int wpos;
 104 static int atom;
 105 static int live;
 106 static int leftover;
 107 static int bytes_per_second;
 108 static void *buf;
 109 static enum {DONT, DSP, TID} estimate = TID;
 110
 111 static void (*copy_fn)(void *, void *, int);
 112
 113 static void copy_no_conversion (void *dst, void *src, int size)
 114 {
 115     memcpy (dst, src, size);
 116 }
 117
 118 static void copy_u16_to_s16 (void *dst, void *src, int size)
 119 {
 120     int i;
 121     uint16_t *out, *in;
 122
 123     out = dst;
 124     in = src;
 125
 126     for (i = 0; i < size / 2; i++) {
 127         out[i] = in[i] + 0x8000;
 128     }
 129 }
 130
 131 static void pab (struct audio_buf_info *abinfo)
 132 {
 133     DEREF (abinfo);
 134
 135     ldebug ("fragments %d, fragstotal %d, fragsize %d, bytes %d\n"
 136             "rpos %d, wpos %d, live %d\n",
 137             abinfo->fragments,
 138             abinfo->fragstotal,
 139             abinfo->fragsize,
 140             abinfo->bytes,
 141             rpos, wpos, live);
 142 }
 143
 144 void AUD_reset (int rfreq, int rnchannels, audfmt_e rfmt)
 145 {
 146     int fmt_;
 147     int bits16;
 148
 149     if (-1 == audio_fd) {
 150         AUD_open (rfreq, rnchannels, rfmt);
 151         return;
 152     }
 153
 154     switch (rfmt) {
 155     case AUD_FMT_U8:
 156         bits16 = 0;
 157         fmt_ = AFMT_U8;
 158         copy_fn = copy_no_conversion;
 159         atom = 1;
 160         break;
 161
 162     case AUD_FMT_S8:
 163         Fail ("can not play 8bit signed");
 164
 165     case AUD_FMT_S16:
 166         bits16 = 1;
 167         fmt_ = AFMT_S16_LE;
 168         copy_fn = copy_no_conversion;
 169         atom = 2;
 170         break;
 171
 172     case AUD_FMT_U16:
 173         bits16 = 1;
 174         fmt_ = AFMT_S16_LE;
 175         copy_fn = copy_u16_to_s16;
 176         atom = 2;
 177         break;
 178
 179     default:
 180         abort ();
 181     }
 182
 183     if ((fmt_ == fmt) && (bits16 + 1 == nchannels) && (rfreq == freq))
 184         return;
 185     else {
 186         AUD_open (rfreq, rnchannels, rfmt);
 187     }
 188 }
 189
 190 void AUD_open (int rfreq, int rnchannels, audfmt_e rfmt)
 191 {
 192     int fmt_;
 193     int mmmmssss;
 194     struct audio_buf_info abinfo;
 195     int _fmt;
 196     int _freq;
 197     int _nchannels;
 198     int bits16;
 199
 200     bits16 = 0;
 201
 202     switch (rfmt) {
 203     case AUD_FMT_U8:
 204         bits16 = 0;
 205         fmt_ = AFMT_U8;
 206         copy_fn = copy_no_conversion;
 207         atom = 1;
 208         break;
 209
 210     case AUD_FMT_S8:
 211         Fail ("can not play 8bit signed");
 212
 213     case AUD_FMT_S16:
 214         bits16 = 1;
 215         fmt_ = AFMT_S16_LE;
 216         copy_fn = copy_no_conversion;
 217         atom = 2;
 218         break;
 219
 220     case AUD_FMT_U16:
 221         bits16 = 1;
 222         fmt_ = AFMT_S16_LE;
 223         copy_fn = copy_u16_to_s16;
 224         atom = 2;
 225         break;
 226
 227     default:
 228         abort ();
 229     }
 230
 231     if (buf) {
 232         free (buf);
 233         buf = 0;
 234     }
 235
 236     if (-1 != audio_fd)
 237         close (audio_fd);
 238
 239     audio_fd = open ("/dev/dsp", O_WRONLY | O_NONBLOCK);
 240     if (-1 == audio_fd) {
 241         ERRFail ("can not open /dev/dsp");
 242     }
 243
 244     _fmt = fmt_;
 245     _freq = rfreq;
 246     _nchannels = rnchannels;
 247
 248     IOCTL ((audio_fd, SNDCTL_DSP_RESET, 1));
 249     IOCTL ((audio_fd, SNDCTL_DSP_SAMPLESIZE, &_fmt));
 250     IOCTL ((audio_fd, SNDCTL_DSP_CHANNELS, &_nchannels));
 251     IOCTL ((audio_fd, SNDCTL_DSP_SPEED, &_freq));
 252     IOCTL ((audio_fd, SNDCTL_DSP_NONBLOCK));
 253
 254     /* from oss.pdf:
 255
 256     The argument to this call is an integer encoded as 0xMMMMSSSS (in
 257     hex). The 16 least significant bits determine the fragment
 258     size. The size is 2^SSSS. For examp le SSSS=0008 gives fragment
 259     size of 256 bytes (2^8). The minimum is 16 bytes (SSSS=4) and the
 260     maximum is total_buffer_size/2. Some devices or processor
 261     architectures may require larger fragments - in this case the
 262     requested fragment size is automatically increased.
 263
 264     So ahem... 4096 = 2^12, and grand total 0x0004000c
 265     */
 266
 267     mmmmssss = (conf_nfrags << 16) | conf_fragsize;
 268     IOCTL ((audio_fd, SNDCTL_DSP_SETFRAGMENT, &mmmmssss));
 269
 270     linfo ("_fmt = %d, fmt = %d\n"
 271            "_channels = %d, rnchannels = %d\n"
 272            "_freq = %d, freq = %d\n",
 273            _fmt, fmt_,
 274            _nchannels, rnchannels,
 275            _freq, rfreq);
 276
 277     if (_fmt != fmt_) {
 278         Fail ("format %d != %d", _fmt, fmt_);
 279     }
 280
 281     if (_nchannels != rnchannels) {
 282         Fail ("channels %d != %d", _nchannels, rnchannels);
 283     }
 284
 285     if (_freq != rfreq) {
 286         Fail ("freq %d != %d", _freq, rfreq);
 287     }
 288
 289     IOCTL ((audio_fd, SNDCTL_DSP_GETOSPACE, &abinfo));
 290
 291     nfrags = abinfo.fragstotal;
 292     fragsize = abinfo.fragsize;
 293     freq = _freq;
 294     fmt = _fmt;
 295     nchannels = rnchannels;
 296     atom <<= nchannels >>  1;
 297     bufsize = nfrags * fragsize;
 298
 299     bytes_per_second = (freq << (nchannels >> 1)) << bits16;
 300
 301     linfo ("bytes per second %d\n", bytes_per_second);
 302
 303     linfo ("fragments %d, fragstotal %d, fragsize %d, bytes %d, bufsize %d\n",
 304            abinfo.fragments,
 305            abinfo.fragstotal,
 306            abinfo.fragsize,
 307            abinfo.bytes,
 308            bufsize);
 309
 310     if (NULL == buf) {
 311         buf = malloc (bufsize);
 312         if (NULL == buf) {
 313             abort ();
 314         }
 315     }
 316
 317     rpos = 0;
 318     wpos = 0;
 319     live = 0;
 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 (bufsize - live, size);
 328
 329     temp = to_copy;
 330
 331     in = in_buf;
 332     out = buf;
 333
 334     while (temp) {
 335         int copy;
 336
 337         copy = MIN (temp, bufsize - wpos);
 338         copy_fn (out + wpos, in, copy);
 339
 340         wpos += copy;
 341         if (wpos == bufsize) {
 342             wpos = 0;
 343         }
 344
 345         temp -= copy;
 346         in += copy;
 347         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 == live)
 360         return;
 361
 362     res = ioctl (audio_fd, SNDCTL_DSP_GETOSPACE, &abinfo);
 363
 364     if (-1 == res) {
 365         int err;
 366
 367         err = errno;
 368         lwarn ("SNDCTL_DSP_GETOSPACE failed with %s\n", strerror (err));
 369     }
 370
 371     bytes = abinfo.bytes;
 372     bytes = MIN (live, bytes);
 373 #if 0
 374     bytes = (bytes / fragsize) * fragsize;
 375 #endif
 376
 377     while (bytes) {
 378         int left, play, written;
 379
 380         left = bufsize - rpos;
 381         play = MIN (left, bytes);
 382         written = write (audio_fd, (void *) ((uint32_t) buf + rpos), play);
 383
 384         if (-1 == written) {
 385             if (EAGAIN == errno || EINTR == errno) {
 386                 return;
 387             }
 388             else {
 389                 ERRFail ("write audio");
 390             }
 391         }
 392
 393         play = written;
 394         live -= play;
 395         rpos += play;
 396         bytes -= play;
 397
 398         if (rpos == bufsize) {
 399             rpos = 0;
 400         }
 401     }
 402 }
 403
 404 static int get_dsp_bytes (void)
 405 {
 406     int res;
 407     struct count_info info;
 408
 409     res = ioctl (audio_fd, SNDCTL_DSP_GETOPTR, &info);
 410     if (-1 == res) {
 411         int err;
 412
 413         err = errno;
 414         lwarn ("SNDCTL_DSP_GETOPTR failed with %s\n", strerror (err));
 415         return -1;
 416     }
 417     else {
 418         ldebug ("bytes %d\n", info.bytes);
 419         return info.bytes;
 420     }
 421 }
 422
 423 void AUD_adjust_estimate (int _leftover)
 424 {
 425     leftover = _leftover;
 426 }
 427
 428 int AUD_get_free (void)
 429 {
 430     int free, elapsed;
 431
 432     free = bufsize - live;
 433
 434     if (0 == free)
 435         return 0;
 436
 437     elapsed = free;
 438     switch (estimate) {
 439     case DONT:
 440         break;
 441
 442     case DSP:
 443         {
 444             static int old_bytes;
 445             int bytes;
 446
 447             bytes = get_dsp_bytes ();
 448             if (bytes <= 0)
 449                 return free;
 450
 451             elapsed = bytes - old_bytes;
 452             old_bytes = bytes;
 453             ldebug ("dsp elapsed %d bytes\n", elapsed);
 454             break;
 455         }
 456
 457     case TID:
 458         {
 459             static uint64_t old_ticks;
 460             uint64_t ticks, delta;
 461             uint64_t ua_elapsed;
 462             uint64_t al_elapsed;
 463
 464             ticks = qemu_get_clock(rt_clock);
 465             delta = ticks - old_ticks;
 466             old_ticks = ticks;
 467
 468             ua_elapsed = (delta * bytes_per_second) / 1000;
 469             al_elapsed = ua_elapsed & ~3ULL;
 470
 471             ldebug ("tid elapsed %llu bytes\n", ua_elapsed);
 472
 473             if (al_elapsed > (uint64_t) INT_MAX)
 474                 elapsed = INT_MAX;
 475             else
 476                 elapsed = al_elapsed;
 477
 478             elapsed += leftover;
 479         }
 480     }
 481
 482     if (elapsed > free) {
 483         lwarn ("audio can not keep up elapsed %d free %d\n", elapsed, free);
 484         return free;
 485     }
 486     else {
 487         return elapsed;
 488     }
 489 }
 490
 491 int AUD_get_live (void)
 492 {
 493     return live;
 494 }
 495
 496 int AUD_get_buffer_size (void)
 497 {
 498     return bufsize;
 499 }
 500
 501 void AUD_init (void)
 502 {
 503     int fsp;
 504     int _fragsize = 4096;
 505
 506     DEREF (pab);
 507
 508     fsp = _fragsize;
 509     if (0 != (fsp & (fsp - 1))) {
 510         Fail ("fragment size %d is not power of 2", fsp);
 511     }
 512
 513     conf_fragsize = lsbindex (fsp);
 514 }
 515
 516 #else
 517
 518 void AUD_run (void)
 519 {
 520 }
 521
 522 int AUD_write (void *in_buf, int size)
 523 {
 524     return 0;
 525 }
 526
 527 void AUD_reset (int rfreq, int rnchannels, audfmt_e rfmt)
 528 {
 529 }
 530
 531 void AUD_adjust_estimate (int _leftover)
 532 {
 533 }
 534
 535 int AUD_get_free (void)
 536 {
 537     return 0;
 538 }
 539
 540 int AUD_get_live (void)
 541 {
 542     return 0;
 543 }
 544
 545 int AUD_get_buffer_size (void)
 546 {
 547     return 0;
 548 }
 549
 550 void AUD_init (void)
 551 {
 552 }
 553
 554 #endif