src/sound.c

   1 /* sound.c -- sound support.
   2    Copyright (C) 1998 Free Software Foundation.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs 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, or (at your option)
   9 any later version.
  10
  11 GNU Emacs 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
  17 along with GNU Emacs; see the file COPYING.  If not, write to
  18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 /* Written by Gerd Moellmann <gerd@gnu.org>.  Tested with Luigi's
  22    driver on FreeBSD 2.2.7 with a SoundBlaster 16.  */
  23
  24 #include <config.h>
  25
  26 #if defined HAVE_SOUND
  27
  28 #include <lisp.h>
  29 #include <fcntl.h>
  30 #include <unistd.h>
  31 #include <sys/types.h>
  32 #include <dispextern.h>
  33 #include <errno.h>
  34
  35 /* FreeBSD has machine/soundcard.h.  Voxware sound driver docs mention
  36    sys/soundcard.h.  So, let's try whatever's there.  */
  37
  38 #ifdef HAVE_MACHINE_SOUNDCARD_H
  39 #include <machine/soundcard.h>
  40 #endif
  41 #ifdef HAVE_SYS_SOUNDCARD_H
  42 #include <sys/soundcard.h>
  43 #endif
  44
  45 #define max(X, Y) ((X) > (Y) ? (X) : (Y))
  46 #define min(X, Y) ((X) < (Y) ? (X) : (Y))
  47 #define abs(X)    ((X) < 0 ? -(X) : (X))
  48
  49 /* Structure forward declarations.  */
  50
  51 struct sound_file;
  52 struct sound_device;
  53
  54 /* The file header of RIFF-WAVE files (*.wav).  Files are always in
  55    little-endian byte-order.  */
  56
  57 struct wav_header
  58 {
  59   u_int32_t magic;
  60   u_int32_t length;
  61   u_int32_t chunk_type;
  62   u_int32_t chunk_format;
  63   u_int32_t chunk_length;
  64   u_int16_t format;
  65   u_int16_t channels;
  66   u_int32_t sample_rate;
  67   u_int32_t bytes_per_second;
  68   u_int16_t sample_size;
  69   u_int16_t precision;
  70   u_int32_t chunk_data;
  71   u_int32_t data_length;
  72 };
  73
  74 /* The file header of Sun adio files (*.au).  Files are always in
  75    big-endian byte-order.  */
  76
  77 struct au_header
  78 {
  79   /* ASCII ".snd" */
  80   u_int32_t magic_number;
  81
  82   /* Offset of data part from start of file. Minimum value is 24.  */
  83   u_int32_t data_offset;
  84
  85   /* Size of data part, 0xffffffff if unknown.  */
  86   u_int32_t data_size;
  87
  88   /* Data encoding format.
  89      1  8-bit ISDN u-law
  90      2  8-bit linear PCM (REF-PCM)
  91      3  16-bit linear PCM
  92      4  24-bit linear PCM
  93      5  32-bit linear PCM
  94      6  32-bit IEEE floating-point
  95      7  64-bit IEEE floating-point
  96      23 8-bit u-law compressed using CCITT 0.721 ADPCM voice data
  97      encoding scheme.  */
  98   u_int32_t encoding;
  99
 100   /* Number of samples per second.  */
 101   u_int32_t sample_rate;
 102
 103   /* Number of interleaved channels.  */
 104   u_int32_t channels;
 105 };
 106
 107 /* Maximum of all sound file headers sizes.  */
 108
 109 #define MAX_SOUND_HEADER_BYTES \
 110      max (sizeof (struct wav_header), sizeof (struct au_header))
 111
 112 /* Interface structure for sound devices.  */
 113
 114 struct sound_device
 115 {
 116   /* The name of the device or null meaning use a default device name.  */
 117   char *file;
 118
 119   /* File descriptor of the device.  */
 120   int fd;
 121
 122   /* Device-dependent format.  */
 123   int format;
 124
 125   /* Volume (0..100).  Zero means unspecified.  */
 126   int volume;
 127
 128   /* Sample size.  */
 129   int sample_size;
 130
 131   /* Sample rate.  */
 132   int sample_rate;
 133
 134   /* Bytes per second.  */
 135   int bps;
 136
 137   /* 1 = mono, 2 = stereo, 0 = don't set.  */
 138   int channels;
 139
 140   /* Open device SD.  */
 141   void (* open) P_ ((struct sound_device *sd));
 142
 143   /* Close device SD.  */
 144   void (* close) P_ ((struct sound_device *sd));
 145
 146   /* Configure SD accoring to device-dependent parameters.  */
 147   void (* configure) P_ ((struct sound_device *device));
 148
 149   /* Choose a device-dependent format for outputting sound file SF.  */
 150   void (* choose_format) P_ ((struct sound_device *sd,
 151                               struct sound_file *sf));
 152
 153   /* Write NYBTES bytes from BUFFER to device SD.  */
 154   void (* write) P_ ((struct sound_device *sd, char *buffer, int nbytes));
 155
 156   /* A place for devices to store additional data.  */
 157   void *data;
 158 };
 159
 160 /* An enumerator for each supported sound file type.  */
 161
 162 enum sound_type
 163 {
 164   RIFF,
 165   SUN_AUDIO
 166 };
 167
 168 /* Interface structure for sound files.  */
 169
 170 struct sound_file
 171 {
 172   /* The type of the file.  */
 173   enum sound_type type;
 174
 175   /* File descriptor of the file.  */
 176   int fd;
 177
 178   /* Pointer to sound file header.  This contains the first
 179      MAX_SOUND_HEADER_BYTES read from the file.  */
 180   char *header;
 181
 182   /* Play sound file SF on device SD.  */
 183   void (* play) P_ ((struct sound_file *sf, struct sound_device *sd));
 184 };
 185
 186 /* Indices of attributes in a sound attributes vector.  */
 187
 188 enum sound_attr
 189 {
 190   SOUND_FILE,
 191   SOUND_DEVICE,
 192   SOUND_VOLUME,
 193   SOUND_ATTR_SENTINEL
 194 };
 195
 196 /* Symbols.  */
 197
 198 extern Lisp_Object QCfile;
 199 Lisp_Object QCvolume, QCdevice;
 200 Lisp_Object Qsound;
 201 Lisp_Object Qplay_sound_functions;
 202
 203 /* These are set during `play-sound' so that sound_cleanup has
 204    access to them.  */
 205
 206 struct sound_device *sound_device;
 207 struct sound_file *sound_file;
 208
 209 /* Function prototypes.  */
 210
 211 static void vox_open P_ ((struct sound_device *));
 212 static void vox_configure P_ ((struct sound_device *));
 213 static void vox_close P_ ((struct sound_device *sd));
 214 static void vox_choose_format P_ ((struct sound_device *, struct sound_file *));
 215 static void vox_init P_ ((struct sound_device *));
 216 static void vox_write P_ ((struct sound_device *, char *, int));
 217 static void sound_perror P_ ((char *));
 218 static int parse_sound P_ ((Lisp_Object, Lisp_Object *));
 219 static void find_sound_file_type P_ ((struct sound_file *));
 220 static u_int32_t le2hl P_ ((u_int32_t));
 221 static u_int16_t le2hs P_ ((u_int16_t));
 222 static u_int32_t be2hl P_ ((u_int32_t));
 223 static int wav_init P_ ((struct sound_file *));
 224 static void wav_play P_ ((struct sound_file *, struct sound_device *));
 225 static int au_init P_ ((struct sound_file *));
 226 static void au_play P_ ((struct sound_file *, struct sound_device *));
 227
 228 #if 0 /* Currently not used.  */
 229 static u_int16_t be2hs P_ ((u_int16_t));
 230 #endif
 231
 232
 233 \f
 234 /***********************************************************************
 235                                General
 236  ***********************************************************************/
 237
 238 /* Like perror, but signals an error.  */
 239
 240 static void
 241 sound_perror (msg)
 242      char *msg;
 243 {
 244   error ("%s: %s", msg, strerror (errno));
 245 }
 246
 247
 248 /* Parse sound specification SOUND, and fill ATTRS with what is
 249    found.  Value is non-zero if SOUND Is a valid sound specification.
 250    A valid sound specification is a list starting with the symbol
 251    `sound'.  The rest of the list is a property list which may
 252    contain the following key/value pairs:
 253
 254    - `:file FILE'
 255
 256    FILE is the sound file to play.  If it isn't an absolute name,
 257    it's searched under `data-directory'.
 258
 259    - `:device DEVICE'
 260
 261    DEVICE is the name of the device to play on, e.g. "/dev/dsp2".
 262    If not specified, a default device is used.
 263
 264    - `:volume VOL'
 265
 266    VOL must be an integer in the range [0, 100], or a float in the
 267    range [0, 1].  */
 268
 269 static int
 270 parse_sound (sound, attrs)
 271      Lisp_Object sound;
 272      Lisp_Object *attrs;
 273 {
 274   /* SOUND must be a list starting with the symbol `sound'.  */
 275   if (!CONSP (sound) || !EQ (XCAR (sound), Qsound))
 276     return 0;
 277
 278   sound = XCDR (sound);
 279   attrs[SOUND_FILE] = Fplist_get (sound, QCfile);
 280   attrs[SOUND_DEVICE] = Fplist_get (sound, QCdevice);
 281   attrs[SOUND_VOLUME] = Fplist_get (sound, QCvolume);
 282
 283   /* File name must be specified.  */
 284   if (!STRINGP (attrs[SOUND_FILE]))
 285     return 0;
 286
 287   /* Volume must be in the range 0..100 or unspecified.  */
 288   if (!NILP (attrs[SOUND_VOLUME]))
 289     {
 290       if (INTEGERP (attrs[SOUND_VOLUME]))
 291         {
 292           if (XINT (attrs[SOUND_VOLUME]) < 0
 293               || XINT (attrs[SOUND_VOLUME]) > 100)
 294             return 0;
 295         }
 296       else if (FLOATP (attrs[SOUND_VOLUME]))
 297         {
 298           if (XFLOAT_DATA (attrs[SOUND_VOLUME]) < 0
 299               || XFLOAT_DATA (attrs[SOUND_VOLUME]) > 1)
 300             return 0;
 301         }
 302       else
 303         return 0;
 304     }
 305
 306   /* Device must be a string or unspecified.  */
 307   if (!NILP (attrs[SOUND_DEVICE])
 308       && !STRINGP (attrs[SOUND_DEVICE]))
 309     return 0;
 310
 311   return 1;
 312 }
 313
 314
 315 /* Find out the type of the sound file whose file descriptor is FD.
 316    SF is the sound file structure to fill in.  */
 317
 318 static void
 319 find_sound_file_type (sf)
 320      struct sound_file *sf;
 321 {
 322   if (!wav_init (sf)
 323       && !au_init (sf))
 324     error ("Unknown sound file format");
 325 }
 326
 327
 328 /* Function installed by play-sound with record_unwind_protect.  */
 329
 330 static Lisp_Object
 331 sound_cleanup (arg)
 332      Lisp_Object arg;
 333 {
 334   if (sound_device)
 335     {
 336       sound_device->close (sound_device);
 337       if (sound_file->fd > 0)
 338         close (sound_file->fd);
 339     }
 340 }
 341
 342
 343 DEFUN ("play-sound", Fplay_sound, Splay_sound, 1, 1, 0,
 344   "Play sound SOUND.")
 345   (sound)
 346      Lisp_Object sound;
 347 {
 348   Lisp_Object attrs[SOUND_ATTR_SENTINEL];
 349   Lisp_Object file;
 350   struct gcpro gcpro1, gcpro2;
 351   int nbytes;
 352   struct sound_device sd;
 353   struct sound_file sf;
 354   Lisp_Object args[2];
 355   int count = specpdl_ptr - specpdl;
 356
 357   file = Qnil;
 358   GCPRO2 (sound, file);
 359   bzero (&sd, sizeof sd);
 360   bzero (&sf, sizeof sf);
 361   sf.header = (char *) alloca (MAX_SOUND_HEADER_BYTES);
 362
 363   sound_device = &sd;
 364   sound_file = &sf;
 365   record_unwind_protect (sound_cleanup, Qnil);
 366
 367   /* Parse the sound specification.  Give up if it is invalid.  */
 368   if (!parse_sound (sound, attrs))
 369     {
 370       UNGCPRO;
 371       error ("Invalid sound specification");
 372     }
 373
 374   /* Open the sound file.  */
 375   sf.fd = openp (Fcons (Vdata_directory, Qnil),
 376                  attrs[SOUND_FILE], "", &file, 0);
 377   if (sf.fd < 0)
 378     sound_perror ("Open sound file");
 379
 380   /* Read the first bytes from the file.  */
 381   nbytes = read (sf.fd, sf.header, MAX_SOUND_HEADER_BYTES);
 382   if (nbytes < 0)
 383     sound_perror ("Reading sound file header");
 384
 385   /* Find out the type of sound file.  Give up if we can't tell.  */
 386   find_sound_file_type (&sf);
 387
 388   /* Set up a device.  */
 389   if (STRINGP (attrs[SOUND_DEVICE]))
 390     {
 391       int len = XSTRING (attrs[SOUND_DEVICE])->size;
 392       sd.file = (char *) alloca (len + 1);
 393       strcpy (sd.file, XSTRING (attrs[SOUND_DEVICE])->data);
 394     }
 395   if (INTEGERP (attrs[SOUND_VOLUME]))
 396     sd.volume = XFASTINT (attrs[SOUND_VOLUME]);
 397   else if (FLOATP (attrs[SOUND_VOLUME]))
 398     sd.volume = XFLOAT_DATA (attrs[SOUND_VOLUME]) * 100;
 399
 400   args[0] = Qplay_sound_functions;
 401   args[1] = sound;
 402   Frun_hook_with_args (make_number (2), args);
 403
 404   vox_init (&sd);
 405   sd.open (&sd);
 406
 407   sf.play (&sf, &sd);
 408   close (sf.fd);
 409   sf.fd = -1;
 410   sd.close (&sd);
 411   sound_device = NULL;
 412   sound_file = NULL;
 413   UNGCPRO;
 414   unbind_to (count, Qnil);
 415   return Qnil;
 416 }
 417
 418 \f
 419 /***********************************************************************
 420                         Byte-order Conversion
 421  ***********************************************************************/
 422
 423 /* Convert 32-bit value VALUE which is in little-endian byte-order
 424    to host byte-order.  */
 425
 426 static u_int32_t
 427 le2hl (value)
 428      u_int32_t value;
 429 {
 430 #ifdef WORDS_BIG_ENDIAN
 431   unsigned char *p = (unsigned char *) &value;
 432   value = p[0] + (p[1] << 8) + (p[2] << 16) + (p[3] << 24);
 433 #endif
 434   return value;
 435 }
 436
 437
 438 /* Convert 16-bit value VALUE which is in little-endian byte-order
 439    to host byte-order.  */
 440
 441 static u_int16_t
 442 le2hs (value)
 443      u_int16_t value;
 444 {
 445 #ifdef WORDS_BIG_ENDIAN
 446   unsigned char *p = (unsigned char *) &value;
 447   value = p[0] + (p[1] << 8);
 448 #endif
 449   return value;
 450 }
 451
 452
 453 /* Convert 32-bit value VALUE which is in big-endian byte-order
 454    to host byte-order.  */
 455
 456 static u_int32_t
 457 be2hl (value)
 458      u_int32_t value;
 459 {
 460 #ifndef WORDS_BIG_ENDIAN
 461   unsigned char *p = (unsigned char *) &value;
 462   value = p[3] + (p[2] << 8) + (p[1] << 16) + (p[0] << 24);
 463 #endif
 464   return value;
 465 }
 466
 467
 468 #if 0 /* Currently not used.  */
 469
 470 /* Convert 16-bit value VALUE which is in big-endian byte-order
 471    to host byte-order.  */
 472
 473 static u_int16_t
 474 be2hs (value)
 475      u_int16_t value;
 476 {
 477 #ifndef WORDS_BIG_ENDIAN
 478   unsigned char *p = (unsigned char *) &value;
 479   value = p[1] + (p[0] << 8);
 480 #endif
 481   return value;
 482 }
 483
 484 #endif /* 0 */
 485
 486 \f
 487 /***********************************************************************
 488                           RIFF-WAVE (*.wav)
 489  ***********************************************************************/
 490
 491 /* Try to initialize sound file SF from SF->header.  SF->header
 492    contains the first MAX_SOUND_HEADER_BYTES number of bytes from the
 493    sound file.  If the file is a WAV-format file, set up interface
 494    functions in SF and convert header fields to host byte-order.
 495    Value is non-zero if the file is a WAV file.  */
 496
 497 static int
 498 wav_init (sf)
 499      struct sound_file *sf;
 500 {
 501   struct wav_header *header = (struct wav_header *) sf->header;
 502
 503   if (bcmp (sf->header, "RIFF", 4) != 0)
 504     return 0;
 505
 506   /* WAV files are in little-endian order.  Convert the header
 507      if on a big-endian machine.  */
 508   header->magic = le2hl (header->magic);
 509   header->length = le2hl (header->length);
 510   header->chunk_type = le2hl (header->chunk_type);
 511   header->chunk_format = le2hl (header->chunk_format);
 512   header->chunk_length = le2hl (header->chunk_length);
 513   header->format = le2hs (header->format);
 514   header->channels = le2hs (header->channels);
 515   header->sample_rate = le2hl (header->sample_rate);
 516   header->bytes_per_second = le2hl (header->bytes_per_second);
 517   header->sample_size = le2hs (header->sample_size);
 518   header->precision = le2hs (header->precision);
 519   header->chunk_data = le2hl (header->chunk_data);
 520   header->data_length = le2hl (header->data_length);
 521
 522   /* Set up the interface functions for WAV.  */
 523   sf->type = RIFF;
 524   sf->play = wav_play;
 525
 526   return 1;
 527 }
 528
 529
 530 /* Play RIFF-WAVE audio file SF on sound device SD.  */
 531
 532 static void
 533 wav_play (sf, sd)
 534      struct sound_file *sf;
 535      struct sound_device *sd;
 536 {
 537   struct wav_header *header = (struct wav_header *) sf->header;
 538   char *buffer;
 539   int nbytes;
 540   int blksize = 2048;
 541
 542   /* Let the device choose a suitable device-dependent format
 543      for the file.  */
 544   sd->choose_format (sd, sf);
 545
 546   /* Configure the device.  */
 547   sd->sample_size = header->sample_size;
 548   sd->sample_rate = header->sample_rate;
 549   sd->bps = header->bytes_per_second;
 550   sd->channels = header->channels;
 551   sd->configure (sd);
 552
 553   /* Copy sound data to the device.  The WAV file specification is
 554      actually more complex.  This simple scheme worked with all WAV
 555      files I found so far.  If someone feels inclined to implement the
 556      whole RIFF-WAVE spec, please do.  */
 557   buffer = (char *) alloca (blksize);
 558   lseek (sf->fd, sizeof *header, SEEK_SET);
 559
 560   while ((nbytes = read (sf->fd, buffer, blksize)) > 0)
 561     sd->write (sd, buffer, nbytes);
 562
 563   if (nbytes < 0)
 564     sound_perror ("Reading sound file");
 565 }
 566
 567
 568 \f
 569 /***********************************************************************
 570                            Sun Audio (*.au)
 571  ***********************************************************************/
 572
 573 /* Sun audio file encodings.  */
 574
 575 enum au_encoding
 576 {
 577   AU_ENCODING_ULAW_8 = 1,
 578   AU_ENCODING_8,
 579   AU_ENCODING_16,
 580   AU_ENCODING_24,
 581   AU_ENCODING_32,
 582   AU_ENCODING_IEEE32,
 583   AU_ENCODING_IEEE64,
 584   AU_COMPRESSED = 23
 585 };
 586
 587
 588 /* Try to initialize sound file SF from SF->header.  SF->header
 589    contains the first MAX_SOUND_HEADER_BYTES number of bytes from the
 590    sound file.  If the file is a AU-format file, set up interface
 591    functions in SF and convert header fields to host byte-order.
 592    Value is non-zero if the file is an AU file.  */
 593
 594 static int
 595 au_init (sf)
 596      struct sound_file *sf;
 597 {
 598   struct au_header *header = (struct au_header *) sf->header;
 599
 600   if (bcmp (sf->header, ".snd", 4) != 0)
 601     return 0;
 602
 603   header->magic_number = be2hl (header->magic_number);
 604   header->data_offset = be2hl (header->data_offset);
 605   header->data_size = be2hl (header->data_size);
 606   header->encoding = be2hl (header->encoding);
 607   header->sample_rate = be2hl (header->sample_rate);
 608   header->channels = be2hl (header->channels);
 609
 610   /* Set up the interface functions for AU.  */
 611   sf->type = SUN_AUDIO;
 612   sf->play = au_play;
 613
 614   return 1;
 615 }
 616
 617
 618 /* Play Sun audio file SF on sound device SD.  */
 619
 620 static void
 621 au_play (sf, sd)
 622      struct sound_file *sf;
 623      struct sound_device *sd;
 624 {
 625   struct au_header *header = (struct au_header *) sf->header;
 626   int blksize = 2048;
 627   char *buffer;
 628   int nbytes;
 629
 630   sd->sample_size = 0;
 631   sd->sample_rate = header->sample_rate;
 632   sd->bps = 0;
 633   sd->channels = header->channels;
 634   sd->choose_format (sd, sf);
 635   sd->configure (sd);
 636
 637   /* Seek */
 638   lseek (sf->fd, header->data_offset, SEEK_SET);
 639
 640   /* Copy sound data to the device.  */
 641   buffer = (char *) alloca (blksize);
 642   while ((nbytes = read (sf->fd, buffer, blksize)) > 0)
 643     sd->write (sd, buffer, nbytes);
 644
 645   if (nbytes < 0)
 646     sound_perror ("Reading sound file");
 647 }
 648
 649
 650 \f
 651 /***********************************************************************
 652                        Voxware Driver Interface
 653  ***********************************************************************/
 654
 655 /* This driver is available on GNU/Linux, and the free BSDs.  FreeBSD
 656    has a compatible own driver aka Luigi's driver.  */
 657
 658
 659 /* Open device SD.  If SD->file is non-null, open that device,
 660    otherwise use a default device name.  */
 661
 662 static void
 663 vox_open (sd)
 664      struct sound_device *sd;
 665 {
 666   char *file;
 667
 668   /* Open the sound device.  Default is /dev/dsp.  */
 669   if (sd->file)
 670     file = sd->file;
 671   else
 672     file = "/dev/dsp";
 673
 674   sd->fd = open (file, O_WRONLY);
 675   if (sd->fd < 0)
 676     sound_perror (file);
 677 }
 678
 679
 680 /* Configure device SD from parameters in it.  */
 681
 682 static void
 683 vox_configure (sd)
 684      struct sound_device *sd;
 685 {
 686   int requested;
 687
 688   xassert (sd->fd >= 0);
 689
 690   /* Device parameters apparently depend on each other in undocumented
 691      ways (not to imply that there is any real documentation).  Be
 692      careful when reordering the calls below.  */
 693   if (sd->sample_size > 0
 694       && ioctl (sd->fd, SNDCTL_DSP_SAMPLESIZE, &sd->sample_size) < 0)
 695     sound_perror ("Setting sample size");
 696
 697   if (sd->bps > 0
 698       && ioctl (sd->fd, SNDCTL_DSP_SPEED, &sd->bps) < 0)
 699     sound_perror ("Setting speed");
 700
 701   if (sd->sample_rate > 0
 702       && ioctl (sd->fd, SOUND_PCM_WRITE_RATE, &sd->sample_rate) < 0)
 703     sound_perror ("Setting sample rate");
 704
 705   requested = sd->format;
 706   if (ioctl (sd->fd, SNDCTL_DSP_SETFMT, &sd->format) < 0)
 707     sound_perror ("Setting format");
 708   else if (requested != sd->format)
 709     error ("Setting format");
 710
 711   if (sd->channels > 1
 712       && ioctl (sd->fd, SNDCTL_DSP_STEREO, &sd->channels) < 0)
 713     sound_perror ("Setting channels");
 714
 715   if (sd->volume > 0
 716       && ioctl (sd->fd, SOUND_MIXER_WRITE_PCM, &sd->volume) < 0)
 717     sound_perror ("Setting volume");
 718 }
 719
 720
 721 /* Close device SD if it is open.  */
 722
 723 static void
 724 vox_close (sd)
 725      struct sound_device *sd;
 726 {
 727   if (sd->fd >= 0)
 728     {
 729       /* Flush sound data, and reset the device.  */
 730       ioctl (sd->fd, SNDCTL_DSP_SYNC, NULL);
 731       ioctl (sd->fd, SNDCTL_DSP_RESET, NULL);
 732
 733       /* Close the device.  */
 734       close (sd->fd);
 735       sd->fd = -1;
 736     }
 737 }
 738
 739
 740 /* Choose device-dependent format for device SD from sound file SF.  */
 741
 742 static void
 743 vox_choose_format (sd, sf)
 744      struct sound_device *sd;
 745      struct sound_file *sf;
 746 {
 747   if (sf->type == RIFF)
 748     {
 749       struct wav_header *h = (struct wav_header *) sf->header;
 750       if (h->precision == 8)
 751         sd->format = AFMT_U8;
 752       else if (h->precision == 16)
 753         sd->format = AFMT_S16_LE;
 754       else
 755         error ("Unsupported WAV file format");
 756     }
 757   else if (sf->type == SUN_AUDIO)
 758     {
 759       struct au_header *header = (struct au_header *) sf->header;
 760       switch (header->encoding)
 761         {
 762         case AU_ENCODING_ULAW_8:
 763         case AU_ENCODING_IEEE32:
 764         case AU_ENCODING_IEEE64:
 765           sd->format = AFMT_MU_LAW;
 766           break;
 767
 768         case AU_ENCODING_8:
 769         case AU_ENCODING_16:
 770         case AU_ENCODING_24:
 771         case AU_ENCODING_32:
 772           sd->format = AFMT_S16_LE;
 773           break;
 774
 775         default:
 776           error ("Unsupported AU file format");
 777         }
 778     }
 779   else
 780     abort ();
 781 }
 782
 783
 784 /* Initialize device SD.  Set up the interface functions in the device
 785    structure.  */
 786
 787 static void
 788 vox_init (sd)
 789      struct sound_device *sd;
 790 {
 791   sd->fd = -1;
 792   sd->open = vox_open;
 793   sd->close = vox_close;
 794   sd->configure = vox_configure;
 795   sd->choose_format = vox_choose_format;
 796   sd->write = vox_write;
 797 }
 798
 799
 800 /* Write NBYTES bytes from BUFFER to device SD.  */
 801
 802 static void
 803 vox_write (sd, buffer, nbytes)
 804      struct sound_device *sd;
 805      char *buffer;
 806      int nbytes;
 807 {
 808   int nwritten = write (sd->fd, buffer, nbytes);
 809   if (nwritten < 0)
 810     sound_perror ("Writing to sound device");
 811 }
 812
 813
 814 \f
 815 /***********************************************************************
 816                             Initialization
 817  ***********************************************************************/
 818
 819 void
 820 syms_of_sound ()
 821 {
 822   QCdevice = intern (":device");
 823   staticpro (&QCdevice);
 824   QCvolume = intern (":volume");
 825   staticpro (&QCvolume);
 826   Qsound = intern ("sound");
 827   staticpro (&Qsound);
 828   Qplay_sound_functions = intern ("play-sound-functions");
 829   staticpro (&Qplay_sound_functions);
 830
 831   defsubr (&Splay_sound);
 832 }
 833
 834
 835 void
 836 init_sound ()
 837 {
 838 }
 839
 840 #endif /* HAVE_SOUND */