libao2/ao_sun.c

   1 /*
   2  * SUN audio output driver
   3  *
   4  * This file is part of MPlayer.
   5  *
   6  * MPlayer is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * MPlayer is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <errno.h>
  28 #include <sys/ioctl.h>
  29 #include <sys/time.h>
  30 #include <sys/types.h>
  31 #include <sys/stat.h>
  32 #include <sys/audioio.h>
  33 #ifdef  AUDIO_SWFEATURE_MIXER   /* solaris8 or newer? */
  34 # define HAVE_SYS_MIXER_H 1
  35 #endif
  36 #if     HAVE_SYS_MIXER_H
  37 # include <sys/mixer.h>
  38 #endif
  39 #ifdef  __svr4__
  40 #include <stropts.h>
  41 #endif
  42
  43 #include "config.h"
  44 #include "mixer.h"
  45
  46 #include "audio_out.h"
  47 #include "audio_out_internal.h"
  48 #include "libaf/af_format.h"
  49 #include "mp_msg.h"
  50
  51 static const ao_info_t info =
  52 {
  53     "Sun audio output",
  54     "sun",
  55     "Juergen Keil",
  56     ""
  57 };
  58
  59 LIBAO_EXTERN(sun)
  60
  61
  62 /* These defines are missing on NetBSD */
  63 #ifndef AUDIO_PRECISION_8
  64 #define AUDIO_PRECISION_8       8
  65 #define AUDIO_PRECISION_16      16
  66 #endif
  67 #ifndef AUDIO_CHANNELS_MONO
  68 #define AUDIO_CHANNELS_MONO     1
  69 #define AUDIO_CHANNELS_STEREO   2
  70 #endif
  71
  72
  73 static char *sun_mixer_device = NULL;
  74 static char *audio_dev = NULL;
  75 static int queued_bursts = 0;
  76 static int queued_samples = 0;
  77 static int bytes_per_sample = 0;
  78 static int byte_per_sec = 0;
  79 static int audio_fd = -1;
  80 static enum {
  81     RTSC_UNKNOWN = 0,
  82     RTSC_ENABLED,
  83     RTSC_DISABLED
  84 } enable_sample_timing;
  85
  86
  87 static void flush_audio(int fd) {
  88 #ifdef AUDIO_FLUSH
  89   ioctl(fd, AUDIO_FLUSH, 0);
  90 #elif defined(__svr4__)
  91   ioctl(fd, I_FLUSH, FLUSHW);
  92 #endif
  93 }
  94
  95 // convert an OSS audio format specification into a sun audio encoding
  96 static int af2sunfmt(int format)
  97 {
  98     switch (format){
  99     case AF_FORMAT_MU_LAW:
 100         return AUDIO_ENCODING_ULAW;
 101     case AF_FORMAT_A_LAW:
 102         return AUDIO_ENCODING_ALAW;
 103     case AF_FORMAT_S16_NE:
 104         return AUDIO_ENCODING_LINEAR;
 105 #ifdef  AUDIO_ENCODING_LINEAR8  // Missing on SunOS 5.5.1...
 106     case AF_FORMAT_U8:
 107         return AUDIO_ENCODING_LINEAR8;
 108 #endif
 109     case AF_FORMAT_S8:
 110         return AUDIO_ENCODING_LINEAR;
 111 #ifdef  AUDIO_ENCODING_DVI      // Missing on NetBSD...
 112     case AF_FORMAT_IMA_ADPCM:
 113         return AUDIO_ENCODING_DVI;
 114 #endif
 115     default:
 116         return AUDIO_ENCODING_NONE;
 117   }
 118 }
 119
 120 // try to figure out, if the soundcard driver provides usable (precise)
 121 // sample counter information
 122 static int realtime_samplecounter_available(char *dev)
 123 {
 124     int fd = -1;
 125     audio_info_t info;
 126     int rtsc_ok = RTSC_DISABLED;
 127     int len;
 128     void *silence = NULL;
 129     struct timeval start, end;
 130     struct timespec delay;
 131     int usec_delay;
 132     unsigned last_samplecnt;
 133     unsigned increment;
 134     unsigned min_increment;
 135
 136     len = 44100 * 4 / 4;    /* amount of data for 0.25sec of 44.1khz, stereo,
 137                              * 16bit.  44kbyte can be sent to all supported
 138                              * sun audio devices without blocking in the
 139                              * "write" below.
 140                              */
 141     silence = calloc(1, len);
 142     if (silence == NULL)
 143         goto error;
 144
 145     if ((fd = open(dev, O_WRONLY)) < 0)
 146         goto error;
 147
 148     AUDIO_INITINFO(&info);
 149     info.play.sample_rate = 44100;
 150     info.play.channels = AUDIO_CHANNELS_STEREO;
 151     info.play.precision = AUDIO_PRECISION_16;
 152     info.play.encoding = AUDIO_ENCODING_LINEAR;
 153     info.play.samples = 0;
 154     if (ioctl(fd, AUDIO_SETINFO, &info)) {
 155         if ( mp_msg_test(MSGT_AO,MSGL_V) )
 156             mp_tmsg(MSGT_AO, MSGL_ERR, "[AO SUN] rtsc: SETINFO failed.\n");
 157         goto error;
 158     }
 159
 160     if (write(fd, silence, len) != len) {
 161         if ( mp_msg_test(MSGT_AO,MSGL_V) )
 162             mp_tmsg(MSGT_AO, MSGL_ERR, "[AO SUN] rtsc: write failed.\n");
 163         goto error;
 164     }
 165
 166     if (ioctl(fd, AUDIO_GETINFO, &info)) {
 167         if ( mp_msg_test(MSGT_AO,MSGL_V) )
 168             perror("rtsc: GETINFO1");
 169         goto error;
 170     }
 171
 172     last_samplecnt = info.play.samples;
 173     min_increment = ~0;
 174
 175     gettimeofday(&start, NULL);
 176     for (;;) {
 177         delay.tv_sec = 0;
 178         delay.tv_nsec = 10000000;
 179         nanosleep(&delay, NULL);
 180         gettimeofday(&end, NULL);
 181         usec_delay = (end.tv_sec - start.tv_sec) * 1000000
 182             + end.tv_usec - start.tv_usec;
 183
 184         // stop monitoring sample counter after 0.2 seconds
 185         if (usec_delay > 200000)
 186             break;
 187
 188         if (ioctl(fd, AUDIO_GETINFO, &info)) {
 189             if ( mp_msg_test(MSGT_AO,MSGL_V) )
 190                 perror("rtsc: GETINFO2 failed");
 191             goto error;
 192         }
 193         if (info.play.samples < last_samplecnt) {
 194             if ( mp_msg_test(MSGT_AO,MSGL_V) )
 195                 mp_msg(MSGT_AO,MSGL_V,"rtsc: %d > %d?\n", last_samplecnt, info.play.samples);
 196             goto error;
 197         }
 198
 199         if ((increment = info.play.samples - last_samplecnt) > 0) {
 200             if ( mp_msg_test(MSGT_AO,MSGL_V) )
 201                 mp_msg(MSGT_AO,MSGL_V,"ao_sun: sample counter increment: %d\n", increment);
 202             if (increment < min_increment) {
 203                 min_increment = increment;
 204                 if (min_increment < 2000)
 205                     break;      // looks good
 206             }
 207         }
 208         last_samplecnt = info.play.samples;
 209     }
 210
 211     /*
 212      * For 44.1kkz, stereo, 16-bit format we would send sound data in 16kbytes
 213      * chunks (== 4096 samples) to the audio device.  If we see a minimum
 214      * sample counter increment from the soundcard driver of less than
 215      * 2000 samples,  we assume that the driver provides a useable realtime
 216      * sample counter in the AUDIO_INFO play.samples field.  Timing based
 217      * on sample counts should be much more accurate than counting whole
 218      * 16kbyte chunks.
 219      */
 220     if (min_increment < 2000)
 221         rtsc_ok = RTSC_ENABLED;
 222
 223     if ( mp_msg_test(MSGT_AO,MSGL_V) )
 224         mp_msg(MSGT_AO,MSGL_V,"ao_sun: minimum sample counter increment per 10msec interval: %d\n"
 225                "\t%susing sample counter based timing code\n",
 226                min_increment, rtsc_ok == RTSC_ENABLED ? "" : "not ");
 227
 228
 229 error:
 230     if (silence != NULL) free(silence);
 231     if (fd >= 0) {
 232         // remove the 0 bytes from the above measurement from the
 233         // audio driver's STREAMS queue
 234         flush_audio(fd);
 235         close(fd);
 236     }
 237
 238     return rtsc_ok;
 239 }
 240
 241
 242 // match the requested sample rate |sample_rate| against the
 243 // sample rates supported by the audio device |dev|.  Return
 244 // a supported sample rate,  if that sample rate is close to
 245 // (< 1% difference) the requested rate; return 0 otherwise.
 246
 247 #define MAX_RATE_ERR    1
 248
 249 static unsigned
 250 find_close_samplerate_match(int dev, unsigned sample_rate)
 251 {
 252 #if     HAVE_SYS_MIXER_H
 253     am_sample_rates_t *sr;
 254     unsigned i, num, err, best_err, best_rate;
 255
 256     for (num = 16; num < 1024; num *= 2) {
 257         sr = malloc(AUDIO_MIXER_SAMP_RATES_STRUCT_SIZE(num));
 258         if (!sr)
 259             return 0;
 260         sr->type = AUDIO_PLAY;
 261         sr->flags = 0;
 262         sr->num_samp_rates = num;
 263         if (ioctl(dev, AUDIO_MIXER_GET_SAMPLE_RATES, sr)) {
 264             free(sr);
 265             return 0;
 266         }
 267         if (sr->num_samp_rates <= num)
 268             break;
 269         free(sr);
 270     }
 271
 272     if (sr->flags & MIXER_SR_LIMITS) {
 273         /*
 274          * HW can playback any rate between
 275          * sr->samp_rates[0] .. sr->samp_rates[1]
 276          */
 277         free(sr);
 278         return 0;
 279     } else {
 280         /* HW supports fixed sample rates only */
 281
 282         best_err = 65535;
 283         best_rate = 0;
 284
 285         for (i = 0; i < sr->num_samp_rates; i++) {
 286             err = abs(sr->samp_rates[i] - sample_rate);
 287             if (err == 0) {
 288                 /*
 289                  * exact supported sample rate match, no need to
 290                  * retry something else
 291                  */
 292                 best_rate = 0;
 293                 break;
 294             }
 295             if (err < best_err) {
 296                 best_err = err;
 297                 best_rate = sr->samp_rates[i];
 298             }
 299         }
 300
 301         free(sr);
 302
 303         if (best_rate > 0 && (100/MAX_RATE_ERR)*best_err < sample_rate) {
 304             /* found a supported sample rate with <1% error? */
 305             return best_rate;
 306         }
 307         return 0;
 308     }
 309 #else   /* old audioio driver, cannot return list of supported rates */
 310     /* XXX: hardcoded sample rates */
 311     unsigned i, err;
 312     unsigned audiocs_rates[] = {
 313         5510, 6620, 8000, 9600, 11025, 16000, 18900, 22050,
 314         27420, 32000, 33075, 37800, 44100, 48000, 0
 315     };
 316
 317     for (i = 0; audiocs_rates[i]; i++) {
 318         err = abs(audiocs_rates[i] - sample_rate);
 319         if (err == 0) {
 320             /*
 321              * exact supported sample rate match, no need to
 322              * retry something elise
 323              */
 324             return 0;
 325         }
 326         if ((100/MAX_RATE_ERR)*err < audiocs_rates[i]) {
 327             /* <1% error? */
 328             return audiocs_rates[i];
 329         }
 330     }
 331
 332     return 0;
 333 #endif
 334 }
 335
 336
 337 // return the highest sample rate supported by audio device |dev|.
 338 static unsigned
 339 find_highest_samplerate(int dev)
 340 {
 341 #if     HAVE_SYS_MIXER_H
 342     am_sample_rates_t *sr;
 343     unsigned i, num, max_rate;
 344
 345     for (num = 16; num < 1024; num *= 2) {
 346         sr = malloc(AUDIO_MIXER_SAMP_RATES_STRUCT_SIZE(num));
 347         if (!sr)
 348             return 0;
 349         sr->type = AUDIO_PLAY;
 350         sr->flags = 0;
 351         sr->num_samp_rates = num;
 352         if (ioctl(dev, AUDIO_MIXER_GET_SAMPLE_RATES, sr)) {
 353             free(sr);
 354             return 0;
 355         }
 356         if (sr->num_samp_rates <= num)
 357             break;
 358         free(sr);
 359     }
 360
 361     if (sr->flags & MIXER_SR_LIMITS) {
 362         /*
 363          * HW can playback any rate between
 364          * sr->samp_rates[0] .. sr->samp_rates[1]
 365          */
 366         max_rate = sr->samp_rates[1];
 367     } else {
 368         /* HW supports fixed sample rates only */
 369         max_rate = 0;
 370         for (i = 0; i < sr->num_samp_rates; i++) {
 371             if (sr->samp_rates[i] > max_rate)
 372                 max_rate = sr->samp_rates[i];
 373         }
 374     }
 375     free(sr);
 376     return max_rate;
 377
 378 #else   /* old audioio driver, cannot return list of supported rates */
 379     return 44100;       /* should be supported even on old ISA SB cards */
 380 #endif
 381 }
 382
 383
 384 static void setup_device_paths(void)
 385 {
 386     if (audio_dev == NULL) {
 387         if ((audio_dev = getenv("AUDIODEV")) == NULL)
 388             audio_dev = "/dev/audio";
 389     }
 390
 391     if (sun_mixer_device == NULL) {
 392         if ((sun_mixer_device = mixer_device) == NULL || !sun_mixer_device[0]) {
 393             sun_mixer_device = malloc(strlen(audio_dev) + 4);
 394             strcpy(sun_mixer_device, audio_dev);
 395             strcat(sun_mixer_device, "ctl");
 396         }
 397     }
 398
 399     if (ao_subdevice) audio_dev = ao_subdevice;
 400 }
 401
 402 // to set/get/query special features/parameters
 403 static int control(int cmd,void *arg){
 404     switch(cmd){
 405     case AOCONTROL_SET_DEVICE:
 406         audio_dev=(char*)arg;
 407         return CONTROL_OK;
 408     case AOCONTROL_QUERY_FORMAT:
 409         return CONTROL_TRUE;
 410     case AOCONTROL_GET_VOLUME:
 411     {
 412         int fd;
 413
 414         if ( !sun_mixer_device )    /* control function is used before init? */
 415             setup_device_paths();
 416
 417         fd=open( sun_mixer_device,O_RDONLY );
 418         if ( fd != -1 )
 419         {
 420             ao_control_vol_t *vol = (ao_control_vol_t *)arg;
 421             float volume;
 422             struct audio_info info;
 423             ioctl( fd,AUDIO_GETINFO,&info);
 424             volume = info.play.gain * 100. / AUDIO_MAX_GAIN;
 425             if ( info.play.balance == AUDIO_MID_BALANCE ) {
 426                 vol->right = vol->left = volume;
 427             } else if ( info.play.balance < AUDIO_MID_BALANCE ) {
 428                 vol->left  = volume;
 429                 vol->right = volume * info.play.balance / AUDIO_MID_BALANCE;
 430             } else {
 431                 vol->left  = volume * (AUDIO_RIGHT_BALANCE-info.play.balance)
 432                                                         / AUDIO_MID_BALANCE;
 433                 vol->right = volume;
 434             }
 435             close( fd );
 436             return CONTROL_OK;
 437         }
 438         return CONTROL_ERROR;
 439     }
 440     case AOCONTROL_SET_VOLUME:
 441     {
 442         ao_control_vol_t *vol = (ao_control_vol_t *)arg;
 443         int fd;
 444
 445         if ( !sun_mixer_device )    /* control function is used before init? */
 446             setup_device_paths();
 447
 448         fd=open( sun_mixer_device,O_RDONLY );
 449         if ( fd != -1 )
 450         {
 451             struct audio_info info;
 452             float volume;
 453             AUDIO_INITINFO(&info);
 454             volume = vol->right > vol->left ? vol->right : vol->left;
 455             if ( volume != 0 ) {
 456                 info.play.gain = volume * AUDIO_MAX_GAIN / 100;
 457                 if ( vol->right == vol->left )
 458                     info.play.balance = AUDIO_MID_BALANCE;
 459                 else
 460                     info.play.balance = (vol->right - vol->left + volume) * AUDIO_RIGHT_BALANCE / (2*volume);
 461             }
 462 #if !defined (__OpenBSD__) && !defined (__NetBSD__)
 463             info.output_muted = (volume == 0);
 464 #endif
 465             ioctl( fd,AUDIO_SETINFO,&info );
 466             close( fd );
 467             return CONTROL_OK;
 468         }
 469         return CONTROL_ERROR;
 470     }
 471     }
 472     return CONTROL_UNKNOWN;
 473 }
 474
 475 // open & setup audio device
 476 // return: 1=success 0=fail
 477 static int init(int rate,int channels,int format,int flags){
 478
 479     audio_info_t info;
 480     int pass;
 481     int ok;
 482     int convert_u8_s8;
 483
 484     setup_device_paths();
 485
 486     if (enable_sample_timing == RTSC_UNKNOWN
 487         && !getenv("AO_SUN_DISABLE_SAMPLE_TIMING")) {
 488         enable_sample_timing = realtime_samplecounter_available(audio_dev);
 489     }
 490
 491     mp_msg(MSGT_AO,MSGL_STATUS,"ao2: %d Hz  %d chans  %s [0x%X]\n",
 492            rate,channels,af_fmt2str_short(format),format);
 493
 494     audio_fd=open(audio_dev, O_WRONLY);
 495     if(audio_fd<0){
 496         mp_tmsg(MSGT_AO, MSGL_ERR, "[AO SUN] Can't open audio device %s, %s  -> nosound.\n", audio_dev, strerror(errno));
 497         return 0;
 498     }
 499
 500     if (af2sunfmt(format) == AUDIO_ENCODING_NONE)
 501       format = AF_FORMAT_S16_NE;
 502
 503     for (ok = pass = 0; pass <= 5; pass++) { /* pass 6&7 not useful */
 504
 505         AUDIO_INITINFO(&info);
 506         info.play.encoding = af2sunfmt(ao_data.format = format);
 507         info.play.precision =
 508             (format==AF_FORMAT_S16_NE
 509              ? AUDIO_PRECISION_16
 510              : AUDIO_PRECISION_8);
 511         info.play.channels = ao_data.channels = channels;
 512         info.play.sample_rate = ao_data.samplerate = rate;
 513
 514         convert_u8_s8 = 0;
 515
 516         if (pass & 1) {
 517             /*
 518              * on some sun audio drivers, 8-bit unsigned LINEAR8 encoding is
 519              * not supported, but 8-bit signed encoding is.
 520              *
 521              * Try S8, and if it works, use our own U8->S8 conversion before
 522              * sending the samples to the sound driver.
 523              */
 524 #ifdef AUDIO_ENCODING_LINEAR8
 525             if (info.play.encoding != AUDIO_ENCODING_LINEAR8)
 526 #endif
 527                 continue;
 528             info.play.encoding = AUDIO_ENCODING_LINEAR;
 529             convert_u8_s8 = 1;
 530         }
 531
 532         if (pass & 2) {
 533             /*
 534              * on some sun audio drivers, only certain fixed sample rates are
 535              * supported.
 536              *
 537              * In case the requested sample rate is very close to one of the
 538              * supported rates,  use the fixed supported rate instead.
 539              */
 540             if (!(info.play.sample_rate =
 541                   find_close_samplerate_match(audio_fd, rate)))
 542               continue;
 543
 544             /*
 545              * I'm not returning the correct sample rate in
 546              * |ao_data.samplerate|, to avoid software resampling.
 547              *
 548              * ao_data.samplerate = info.play.sample_rate;
 549              */
 550         }
 551
 552         if (pass & 4) {
 553             /* like "pass & 2", but use the highest supported sample rate */
 554             if (!(info.play.sample_rate
 555                   = ao_data.samplerate
 556                   = find_highest_samplerate(audio_fd)))
 557                 continue;
 558         }
 559
 560         ok = ioctl(audio_fd, AUDIO_SETINFO, &info) >= 0;
 561         if (ok) {
 562             /* audio format accepted by audio driver */
 563             break;
 564         }
 565
 566         /*
 567          * format not supported?
 568          * retry with different encoding and/or sample rate
 569          */
 570     }
 571
 572     if (!ok) {
 573         char buf[128];
 574         mp_tmsg(MSGT_AO, MSGL_ERR, "[AO SUN] audio_setup: your card doesn't support %d channel, %s, %d Hz samplerate.\n",
 575                channels, af_fmt2str(format, buf, 128), rate);
 576         return 0;
 577     }
 578
 579     if (convert_u8_s8)
 580       ao_data.format = AF_FORMAT_S8;
 581
 582     bytes_per_sample = channels * info.play.precision / 8;
 583     ao_data.bps = byte_per_sec = bytes_per_sample * ao_data.samplerate;
 584     ao_data.outburst = byte_per_sec > 100000 ? 16384 : 8192;
 585
 586     reset();
 587
 588     return 1;
 589 }
 590
 591 // close audio device
 592 static void uninit(int immed){
 593     // throw away buffered data in the audio driver's STREAMS queue
 594     if (immed)
 595         flush_audio(audio_fd);
 596     else
 597         ioctl(audio_fd, AUDIO_DRAIN, 0);
 598     close(audio_fd);
 599 }
 600
 601 // stop playing and empty buffers (for seeking/pause)
 602 static void reset(void){
 603     audio_info_t info;
 604     flush_audio(audio_fd);
 605
 606     AUDIO_INITINFO(&info);
 607     info.play.samples = 0;
 608     info.play.eof = 0;
 609     info.play.error = 0;
 610     ioctl(audio_fd, AUDIO_SETINFO, &info);
 611
 612     queued_bursts = 0;
 613     queued_samples = 0;
 614 }
 615
 616 // stop playing, keep buffers (for pause)
 617 static void audio_pause(void)
 618 {
 619     struct audio_info info;
 620     AUDIO_INITINFO(&info);
 621     info.play.pause = 1;
 622     ioctl(audio_fd, AUDIO_SETINFO, &info);
 623 }
 624
 625 // resume playing, after audio_pause()
 626 static void audio_resume(void)
 627 {
 628     struct audio_info info;
 629     AUDIO_INITINFO(&info);
 630     info.play.pause = 0;
 631     ioctl(audio_fd, AUDIO_SETINFO, &info);
 632 }
 633
 634
 635 // return: how many bytes can be played without blocking
 636 static int get_space(void){
 637     audio_info_t info;
 638
 639     // check buffer
 640 #ifdef HAVE_AUDIO_SELECT
 641     {
 642         fd_set rfds;
 643         struct timeval tv;
 644         FD_ZERO(&rfds);
 645         FD_SET(audio_fd, &rfds);
 646         tv.tv_sec = 0;
 647         tv.tv_usec = 0;
 648         if(!select(audio_fd+1, NULL, &rfds, NULL, &tv)) return 0; // not block!
 649     }
 650 #endif
 651
 652     ioctl(audio_fd, AUDIO_GETINFO, &info);
 653 #if !defined (__OpenBSD__) && !defined(__NetBSD__)
 654     if (queued_bursts - info.play.eof > 2)
 655         return 0;
 656     return ao_data.outburst;
 657 #else
 658     return info.hiwat * info.blocksize - info.play.seek;
 659 #endif
 660
 661 }
 662
 663 // plays 'len' bytes of 'data'
 664 // it should round it down to outburst*n
 665 // return: number of bytes played
 666 static int play(void* data,int len,int flags){
 667     if (!(flags & AOPLAY_FINAL_CHUNK)) {
 668         len /= ao_data.outburst;
 669         len *= ao_data.outburst;
 670     }
 671     if (len <= 0) return 0;
 672
 673     len = write(audio_fd, data, len);
 674     if(len > 0) {
 675         queued_samples += len / bytes_per_sample;
 676         if (write(audio_fd,data,0) < 0)
 677             perror("ao_sun: send EOF audio record");
 678         else
 679             queued_bursts ++;
 680     }
 681     return len;
 682 }
 683
 684
 685 // return: delay in seconds between first and last sample in buffer
 686 static float get_delay(void){
 687     audio_info_t info;
 688     ioctl(audio_fd, AUDIO_GETINFO, &info);
 689 #if defined (__OpenBSD__) || defined(__NetBSD__)
 690     return (float) info.play.seek/ (float)byte_per_sec ;
 691 #else
 692     if (info.play.samples && enable_sample_timing == RTSC_ENABLED)
 693         return (float)(queued_samples - info.play.samples) / (float)ao_data.samplerate;
 694     else
 695         return (float)((queued_bursts - info.play.eof) * ao_data.outburst) / (float)byte_per_sec;
 696 #endif
 697 }