sound/core/pcm_misc.c

   1 /*
   2  *  PCM Interface - misc routines
   3  *  Copyright (c) 1998 by Jaroslav Kysela <perex@suse.cz>
   4  *
   5  *
   6  *   This library is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU Library General Public License as
   8  *   published by the Free Software Foundation; either version 2 of
   9  *   the License, or (at your option) any later version.
  10  *
  11  *   This program 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 Library General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU Library General Public
  17  *   License along with this library; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <sound/driver.h>
  23 #include <linux/time.h>
  24 #include <sound/core.h>
  25 #include <sound/pcm.h>
  26 #define SND_PCM_FORMAT_UNKNOWN (-1)
  27
  28 /* NOTE: "signed" prefix must be given below since the default char is
  29  *       unsigned on some architectures!
  30  */
  31 struct pcm_format_data {
  32         unsigned char width;    /* bit width */
  33         unsigned char phys;     /* physical bit width */
  34         signed char le; /* 0 = big-endian, 1 = little-endian, -1 = others */
  35         signed char signd;      /* 0 = unsigned, 1 = signed, -1 = others */
  36         unsigned char silence[8];       /* silence data to fill */
  37 };
  38
  39 static struct pcm_format_data pcm_formats[SNDRV_PCM_FORMAT_LAST+1] = {
  40         [SNDRV_PCM_FORMAT_S8] = {
  41                 .width = 8, .phys = 8, .le = -1, .signd = 1,
  42                 .silence = {},
  43         },
  44         [SNDRV_PCM_FORMAT_U8] = {
  45                 .width = 8, .phys = 8, .le = -1, .signd = 0,
  46                 .silence = { 0x80 },
  47         },
  48         [SNDRV_PCM_FORMAT_S16_LE] = {
  49                 .width = 16, .phys = 16, .le = 1, .signd = 1,
  50                 .silence = {},
  51         },
  52         [SNDRV_PCM_FORMAT_S16_BE] = {
  53                 .width = 16, .phys = 16, .le = 0, .signd = 1,
  54                 .silence = {},
  55         },
  56         [SNDRV_PCM_FORMAT_U16_LE] = {
  57                 .width = 16, .phys = 16, .le = 1, .signd = 0,
  58                 .silence = { 0x00, 0x80 },
  59         },
  60         [SNDRV_PCM_FORMAT_U16_BE] = {
  61                 .width = 16, .phys = 16, .le = 0, .signd = 0,
  62                 .silence = { 0x80, 0x00 },
  63         },
  64         [SNDRV_PCM_FORMAT_S24_LE] = {
  65                 .width = 24, .phys = 32, .le = 1, .signd = 1,
  66                 .silence = {},
  67         },
  68         [SNDRV_PCM_FORMAT_S24_BE] = {
  69                 .width = 24, .phys = 32, .le = 0, .signd = 1,
  70                 .silence = {},
  71         },
  72         [SNDRV_PCM_FORMAT_U24_LE] = {
  73                 .width = 24, .phys = 32, .le = 1, .signd = 0,
  74                 .silence = { 0x00, 0x00, 0x80 },
  75         },
  76         [SNDRV_PCM_FORMAT_U24_BE] = {
  77                 .width = 24, .phys = 32, .le = 0, .signd = 0,
  78                 .silence = { 0x80, 0x00, 0x00 },
  79         },
  80         [SNDRV_PCM_FORMAT_S32_LE] = {
  81                 .width = 32, .phys = 32, .le = 1, .signd = 1,
  82                 .silence = {},
  83         },
  84         [SNDRV_PCM_FORMAT_S32_BE] = {
  85                 .width = 32, .phys = 32, .le = 0, .signd = 1,
  86                 .silence = {},
  87         },
  88         [SNDRV_PCM_FORMAT_U32_LE] = {
  89                 .width = 32, .phys = 32, .le = 1, .signd = 0,
  90                 .silence = { 0x00, 0x00, 0x00, 0x80 },
  91         },
  92         [SNDRV_PCM_FORMAT_U32_BE] = {
  93                 .width = 32, .phys = 32, .le = 0, .signd = 0,
  94                 .silence = { 0x80, 0x00, 0x00, 0x00 },
  95         },
  96         [SNDRV_PCM_FORMAT_FLOAT_LE] = {
  97                 .width = 32, .phys = 32, .le = 1, .signd = -1,
  98                 .silence = {},
  99         },
 100         [SNDRV_PCM_FORMAT_FLOAT_BE] = {
 101                 .width = 32, .phys = 32, .le = 0, .signd = -1,
 102                 .silence = {},
 103         },
 104         [SNDRV_PCM_FORMAT_FLOAT64_LE] = {
 105                 .width = 64, .phys = 64, .le = 1, .signd = -1,
 106                 .silence = {},
 107         },
 108         [SNDRV_PCM_FORMAT_FLOAT64_BE] = {
 109                 .width = 64, .phys = 64, .le = 0, .signd = -1,
 110                 .silence = {},
 111         },
 112         [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
 113                 .width = 32, .phys = 32, .le = 1, .signd = -1,
 114                 .silence = {},
 115         },
 116         [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
 117                 .width = 32, .phys = 32, .le = 0, .signd = -1,
 118                 .silence = {},
 119         },
 120         [SNDRV_PCM_FORMAT_MU_LAW] = {
 121                 .width = 8, .phys = 8, .le = -1, .signd = -1,
 122                 .silence = { 0x7f },
 123         },
 124         [SNDRV_PCM_FORMAT_A_LAW] = {
 125                 .width = 8, .phys = 8, .le = -1, .signd = -1,
 126                 .silence = { 0x55 },
 127         },
 128         [SNDRV_PCM_FORMAT_IMA_ADPCM] = {
 129                 .width = 4, .phys = 4, .le = -1, .signd = -1,
 130                 .silence = {},
 131         },
 132         /* FIXME: the following three formats are not defined properly yet */
 133         [SNDRV_PCM_FORMAT_MPEG] = {
 134                 .le = -1, .signd = -1,
 135         },
 136         [SNDRV_PCM_FORMAT_GSM] = {
 137                 .le = -1, .signd = -1,
 138         },
 139         [SNDRV_PCM_FORMAT_SPECIAL] = {
 140                 .le = -1, .signd = -1,
 141         },
 142         [SNDRV_PCM_FORMAT_S24_3LE] = {
 143                 .width = 24, .phys = 24, .le = 1, .signd = 1,
 144                 .silence = {},
 145         },
 146         [SNDRV_PCM_FORMAT_S24_3BE] = {
 147                 .width = 24, .phys = 24, .le = 0, .signd = 1,
 148                 .silence = {},
 149         },
 150         [SNDRV_PCM_FORMAT_U24_3LE] = {
 151                 .width = 24, .phys = 24, .le = 1, .signd = 0,
 152                 .silence = { 0x00, 0x00, 0x80 },
 153         },
 154         [SNDRV_PCM_FORMAT_U24_3BE] = {
 155                 .width = 24, .phys = 24, .le = 0, .signd = 0,
 156                 .silence = { 0x80, 0x00, 0x00 },
 157         },
 158         [SNDRV_PCM_FORMAT_S20_3LE] = {
 159                 .width = 20, .phys = 24, .le = 1, .signd = 1,
 160                 .silence = {},
 161         },
 162         [SNDRV_PCM_FORMAT_S20_3BE] = {
 163                 .width = 20, .phys = 24, .le = 0, .signd = 1,
 164                 .silence = {},
 165         },
 166         [SNDRV_PCM_FORMAT_U20_3LE] = {
 167                 .width = 20, .phys = 24, .le = 1, .signd = 0,
 168                 .silence = { 0x00, 0x00, 0x08 },
 169         },
 170         [SNDRV_PCM_FORMAT_U20_3BE] = {
 171                 .width = 20, .phys = 24, .le = 0, .signd = 0,
 172                 .silence = { 0x08, 0x00, 0x00 },
 173         },
 174         [SNDRV_PCM_FORMAT_S18_3LE] = {
 175                 .width = 18, .phys = 24, .le = 1, .signd = 1,
 176                 .silence = {},
 177         },
 178         [SNDRV_PCM_FORMAT_S18_3BE] = {
 179                 .width = 18, .phys = 24, .le = 0, .signd = 1,
 180                 .silence = {},
 181         },
 182         [SNDRV_PCM_FORMAT_U18_3LE] = {
 183                 .width = 18, .phys = 24, .le = 1, .signd = 0,
 184                 .silence = { 0x00, 0x00, 0x02 },
 185         },
 186         [SNDRV_PCM_FORMAT_U18_3BE] = {
 187                 .width = 18, .phys = 24, .le = 0, .signd = 0,
 188                 .silence = { 0x02, 0x00, 0x00 },
 189         },
 190 };
 191
 192
 193 /**
 194  * snd_pcm_format_signed - Check the PCM format is signed linear
 195  * @format: the format to check
 196  *
 197  * Returns 1 if the given PCM format is signed linear, 0 if unsigned
 198  * linear, and a negative error code for non-linear formats.
 199  */
 200 int snd_pcm_format_signed(snd_pcm_format_t format)
 201 {
 202         int val;
 203         if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 204                 return -EINVAL;
 205         if ((val = pcm_formats[format].signd) < 0)
 206                 return -EINVAL;
 207         return val;
 208 }
 209
 210 /**
 211  * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
 212  * @format: the format to check
 213  *
 214  * Returns 1 if the given PCM format is unsigned linear, 0 if signed
 215  * linear, and a negative error code for non-linear formats.
 216  */
 217 int snd_pcm_format_unsigned(snd_pcm_format_t format)
 218 {
 219         int val;
 220
 221         val = snd_pcm_format_signed(format);
 222         if (val < 0)
 223                 return val;
 224         return !val;
 225 }
 226
 227 /**
 228  * snd_pcm_format_linear - Check the PCM format is linear
 229  * @format: the format to check
 230  *
 231  * Returns 1 if the given PCM format is linear, 0 if not.
 232  */
 233 int snd_pcm_format_linear(snd_pcm_format_t format)
 234 {
 235         return snd_pcm_format_signed(format) >= 0;
 236 }
 237
 238 /**
 239  * snd_pcm_format_little_endian - Check the PCM format is little-endian
 240  * @format: the format to check
 241  *
 242  * Returns 1 if the given PCM format is little-endian, 0 if
 243  * big-endian, or a negative error code if endian not specified.
 244  */
 245 int snd_pcm_format_little_endian(snd_pcm_format_t format)
 246 {
 247         int val;
 248         if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 249                 return -EINVAL;
 250         if ((val = pcm_formats[format].le) < 0)
 251                 return -EINVAL;
 252         return val;
 253 }
 254
 255 /**
 256  * snd_pcm_format_big_endian - Check the PCM format is big-endian
 257  * @format: the format to check
 258  *
 259  * Returns 1 if the given PCM format is big-endian, 0 if
 260  * little-endian, or a negative error code if endian not specified.
 261  */
 262 int snd_pcm_format_big_endian(snd_pcm_format_t format)
 263 {
 264         int val;
 265
 266         val = snd_pcm_format_little_endian(format);
 267         if (val < 0)
 268                 return val;
 269         return !val;
 270 }
 271
 272 /**
 273  * snd_pcm_format_width - return the bit-width of the format
 274  * @format: the format to check
 275  *
 276  * Returns the bit-width of the format, or a negative error code
 277  * if unknown format.
 278  */
 279 int snd_pcm_format_width(snd_pcm_format_t format)
 280 {
 281         int val;
 282         if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 283                 return -EINVAL;
 284         if ((val = pcm_formats[format].width) == 0)
 285                 return -EINVAL;
 286         return val;
 287 }
 288
 289 /**
 290  * snd_pcm_format_physical_width - return the physical bit-width of the format
 291  * @format: the format to check
 292  *
 293  * Returns the physical bit-width of the format, or a negative error code
 294  * if unknown format.
 295  */
 296 int snd_pcm_format_physical_width(snd_pcm_format_t format)
 297 {
 298         int val;
 299         if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 300                 return -EINVAL;
 301         if ((val = pcm_formats[format].phys) == 0)
 302                 return -EINVAL;
 303         return val;
 304 }
 305
 306 /**
 307  * snd_pcm_format_size - return the byte size of samples on the given format
 308  * @format: the format to check
 309  *
 310  * Returns the byte size of the given samples for the format, or a
 311  * negative error code if unknown format.
 312  */
 313 ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
 314 {
 315         int phys_width = snd_pcm_format_physical_width(format);
 316         if (phys_width < 0)
 317                 return -EINVAL;
 318         return samples * phys_width / 8;
 319 }
 320
 321 /**
 322  * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
 323  * @format: the format to check
 324  *
 325  * Returns the format pattern to fill or NULL if error.
 326  */
 327 const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
 328 {
 329         if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 330                 return NULL;
 331         if (! pcm_formats[format].phys)
 332                 return NULL;
 333         return pcm_formats[format].silence;
 334 }
 335
 336 /**
 337  * snd_pcm_format_set_silence - set the silence data on the buffer
 338  * @format: the PCM format
 339  * @data: the buffer pointer
 340  * @samples: the number of samples to set silence
 341  *
 342  * Sets the silence data on the buffer for the given samples.
 343  *
 344  * Returns zero if successful, or a negative error code on failure.
 345  */
 346 int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
 347 {
 348         int width;
 349         unsigned char *dst, *pat;
 350
 351         if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 352                 return -EINVAL;
 353         if (samples == 0)
 354                 return 0;
 355         width = pcm_formats[format].phys; /* physical width */
 356         pat = pcm_formats[format].silence;
 357         if (! width)
 358                 return -EINVAL;
 359         /* signed or 1 byte data */
 360         if (pcm_formats[format].signd == 1 || width <= 8) {
 361                 unsigned int bytes = samples * width / 8;
 362                 memset(data, *pat, bytes);
 363                 return 0;
 364         }
 365         /* non-zero samples, fill using a loop */
 366         width /= 8;
 367         dst = data;
 368 #if 0
 369         while (samples--) {
 370                 memcpy(dst, pat, width);
 371                 dst += width;
 372         }
 373 #else
 374         /* a bit optimization for constant width */
 375         switch (width) {
 376         case 2:
 377                 while (samples--) {
 378                         memcpy(dst, pat, 2);
 379                         dst += 2;
 380                 }
 381                 break;
 382         case 3:
 383                 while (samples--) {
 384                         memcpy(dst, pat, 3);
 385                         dst += 3;
 386                 }
 387                 break;
 388         case 4:
 389                 while (samples--) {
 390                         memcpy(dst, pat, 4);
 391                         dst += 4;
 392                 }
 393                 break;
 394         case 8:
 395                 while (samples--) {
 396                         memcpy(dst, pat, 8);
 397                         dst += 8;
 398                 }
 399                 break;
 400         }
 401 #endif
 402         return 0;
 403 }
 404
 405 /* [width][unsigned][bigendian] */
 406 static int linear_formats[4][2][2] = {
 407         {{ SNDRV_PCM_FORMAT_S8, SNDRV_PCM_FORMAT_S8},
 408          { SNDRV_PCM_FORMAT_U8, SNDRV_PCM_FORMAT_U8}},
 409         {{SNDRV_PCM_FORMAT_S16_LE, SNDRV_PCM_FORMAT_S16_BE},
 410          {SNDRV_PCM_FORMAT_U16_LE, SNDRV_PCM_FORMAT_U16_BE}},
 411         {{SNDRV_PCM_FORMAT_S24_LE, SNDRV_PCM_FORMAT_S24_BE},
 412          {SNDRV_PCM_FORMAT_U24_LE, SNDRV_PCM_FORMAT_U24_BE}},
 413         {{SNDRV_PCM_FORMAT_S32_LE, SNDRV_PCM_FORMAT_S32_BE},
 414          {SNDRV_PCM_FORMAT_U32_LE, SNDRV_PCM_FORMAT_U32_BE}}
 415 };
 416
 417 /**
 418  * snd_pcm_build_linear_format - return the suitable linear format for the given condition
 419  * @width: the bit-width
 420  * @unsignd: 1 if unsigned, 0 if signed.
 421  * @big_endian: 1 if big-endian, 0 if little-endian
 422  *
 423  * Returns the suitable linear format for the given condition.
 424  */
 425 snd_pcm_format_t snd_pcm_build_linear_format(int width, int unsignd, int big_endian)
 426 {
 427         if (width & 7)
 428                 return SND_PCM_FORMAT_UNKNOWN;
 429         width = (width / 8) - 1;
 430         if (width < 0 || width >= 4)
 431                 return SND_PCM_FORMAT_UNKNOWN;
 432         return linear_formats[width][!!unsignd][!!big_endian];
 433 }
 434
 435 /**
 436  * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields
 437  * @runtime: the runtime instance
 438  *
 439  * Determines the rate_min and rate_max fields from the rates bits of
 440  * the given runtime->hw.
 441  *
 442  * Returns zero if successful.
 443  */
 444 int snd_pcm_limit_hw_rates(snd_pcm_runtime_t *runtime)
 445 {
 446         static unsigned rates[] = {
 447                 /* ATTENTION: these values depend on the definition in pcm.h! */
 448                 5512, 8000, 11025, 16000, 22050, 32000, 44100, 48000,
 449                 64000, 88200, 96000, 176400, 192000
 450         };
 451         int i;
 452         for (i = 0; i < (int)ARRAY_SIZE(rates); i++) {
 453                 if (runtime->hw.rates & (1 << i)) {
 454                         runtime->hw.rate_min = rates[i];
 455                         break;
 456                 }
 457         }
 458         for (i = (int)ARRAY_SIZE(rates) - 1; i >= 0; i--) {
 459                 if (runtime->hw.rates & (1 << i)) {
 460                         runtime->hw.rate_max = rates[i];
 461                         break;
 462                 }
 463         }
 464         return 0;
 465 }