sound/core/pcm_misc.c

   1 /*
   2  *  PCM Interface - misc routines
   3  *  Copyright (c) 1998 by Jaroslav Kysela <perex@perex.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 <linux/time.h>
  23 #include <sound/core.h>
  24 #include <sound/pcm.h>
  25 #define SND_PCM_FORMAT_UNKNOWN (-1)
  26
  27 /* NOTE: "signed" prefix must be given below since the default char is
  28  *       unsigned on some architectures!
  29  */
  30 struct pcm_format_data {
  31         unsigned char width;    /* bit width */
  32         unsigned char phys;     /* physical bit width */
  33         signed char le; /* 0 = big-endian, 1 = little-endian, -1 = others */
  34         signed char signd;      /* 0 = unsigned, 1 = signed, -1 = others */
  35         unsigned char silence[8];       /* silence data to fill */
  36 };
  37
  38 static struct pcm_format_data pcm_formats[SNDRV_PCM_FORMAT_LAST+1] = {
  39         [SNDRV_PCM_FORMAT_S8] = {
  40                 .width = 8, .phys = 8, .le = -1, .signd = 1,
  41                 .silence = {},
  42         },
  43         [SNDRV_PCM_FORMAT_U8] = {
  44                 .width = 8, .phys = 8, .le = -1, .signd = 0,
  45                 .silence = { 0x80 },
  46         },
  47         [SNDRV_PCM_FORMAT_S16_LE] = {
  48                 .width = 16, .phys = 16, .le = 1, .signd = 1,
  49                 .silence = {},
  50         },
  51         [SNDRV_PCM_FORMAT_S16_BE] = {
  52                 .width = 16, .phys = 16, .le = 0, .signd = 1,
  53                 .silence = {},
  54         },
  55         [SNDRV_PCM_FORMAT_U16_LE] = {
  56                 .width = 16, .phys = 16, .le = 1, .signd = 0,
  57                 .silence = { 0x00, 0x80 },
  58         },
  59         [SNDRV_PCM_FORMAT_U16_BE] = {
  60                 .width = 16, .phys = 16, .le = 0, .signd = 0,
  61                 .silence = { 0x80, 0x00 },
  62         },
  63         [SNDRV_PCM_FORMAT_S24_LE] = {
  64                 .width = 24, .phys = 32, .le = 1, .signd = 1,
  65                 .silence = {},
  66         },
  67         [SNDRV_PCM_FORMAT_S24_BE] = {
  68                 .width = 24, .phys = 32, .le = 0, .signd = 1,
  69                 .silence = {},
  70         },
  71         [SNDRV_PCM_FORMAT_U24_LE] = {
  72                 .width = 24, .phys = 32, .le = 1, .signd = 0,
  73                 .silence = { 0x00, 0x00, 0x80 },
  74         },
  75         [SNDRV_PCM_FORMAT_U24_BE] = {
  76                 .width = 24, .phys = 32, .le = 0, .signd = 0,
  77                 .silence = { 0x00, 0x80, 0x00, 0x00 },
  78         },
  79         [SNDRV_PCM_FORMAT_S32_LE] = {
  80                 .width = 32, .phys = 32, .le = 1, .signd = 1,
  81                 .silence = {},
  82         },
  83         [SNDRV_PCM_FORMAT_S32_BE] = {
  84                 .width = 32, .phys = 32, .le = 0, .signd = 1,
  85                 .silence = {},
  86         },
  87         [SNDRV_PCM_FORMAT_U32_LE] = {
  88                 .width = 32, .phys = 32, .le = 1, .signd = 0,
  89                 .silence = { 0x00, 0x00, 0x00, 0x80 },
  90         },
  91         [SNDRV_PCM_FORMAT_U32_BE] = {
  92                 .width = 32, .phys = 32, .le = 0, .signd = 0,
  93                 .silence = { 0x80, 0x00, 0x00, 0x00 },
  94         },
  95         [SNDRV_PCM_FORMAT_FLOAT_LE] = {
  96                 .width = 32, .phys = 32, .le = 1, .signd = -1,
  97                 .silence = {},
  98         },
  99         [SNDRV_PCM_FORMAT_FLOAT_BE] = {
 100                 .width = 32, .phys = 32, .le = 0, .signd = -1,
 101                 .silence = {},
 102         },
 103         [SNDRV_PCM_FORMAT_FLOAT64_LE] = {
 104                 .width = 64, .phys = 64, .le = 1, .signd = -1,
 105                 .silence = {},
 106         },
 107         [SNDRV_PCM_FORMAT_FLOAT64_BE] = {
 108                 .width = 64, .phys = 64, .le = 0, .signd = -1,
 109                 .silence = {},
 110         },
 111         [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
 112                 .width = 32, .phys = 32, .le = 1, .signd = -1,
 113                 .silence = {},
 114         },
 115         [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
 116                 .width = 32, .phys = 32, .le = 0, .signd = -1,
 117                 .silence = {},
 118         },
 119         [SNDRV_PCM_FORMAT_MU_LAW] = {
 120                 .width = 8, .phys = 8, .le = -1, .signd = -1,
 121                 .silence = { 0x7f },
 122         },
 123         [SNDRV_PCM_FORMAT_A_LAW] = {
 124                 .width = 8, .phys = 8, .le = -1, .signd = -1,
 125                 .silence = { 0x55 },
 126         },
 127         [SNDRV_PCM_FORMAT_IMA_ADPCM] = {
 128                 .width = 4, .phys = 4, .le = -1, .signd = -1,
 129                 .silence = {},
 130         },
 131         /* FIXME: the following three formats are not defined properly yet */
 132         [SNDRV_PCM_FORMAT_MPEG] = {
 133                 .le = -1, .signd = -1,
 134         },
 135         [SNDRV_PCM_FORMAT_GSM] = {
 136                 .le = -1, .signd = -1,
 137         },
 138         [SNDRV_PCM_FORMAT_SPECIAL] = {
 139                 .le = -1, .signd = -1,
 140         },
 141         [SNDRV_PCM_FORMAT_S24_3LE] = {
 142                 .width = 24, .phys = 24, .le = 1, .signd = 1,
 143                 .silence = {},
 144         },
 145         [SNDRV_PCM_FORMAT_S24_3BE] = {
 146                 .width = 24, .phys = 24, .le = 0, .signd = 1,
 147                 .silence = {},
 148         },
 149         [SNDRV_PCM_FORMAT_U24_3LE] = {
 150                 .width = 24, .phys = 24, .le = 1, .signd = 0,
 151                 .silence = { 0x00, 0x00, 0x80 },
 152         },
 153         [SNDRV_PCM_FORMAT_U24_3BE] = {
 154                 .width = 24, .phys = 24, .le = 0, .signd = 0,
 155                 .silence = { 0x80, 0x00, 0x00 },
 156         },
 157         [SNDRV_PCM_FORMAT_S20_3LE] = {
 158                 .width = 20, .phys = 24, .le = 1, .signd = 1,
 159                 .silence = {},
 160         },
 161         [SNDRV_PCM_FORMAT_S20_3BE] = {
 162                 .width = 20, .phys = 24, .le = 0, .signd = 1,
 163                 .silence = {},
 164         },
 165         [SNDRV_PCM_FORMAT_U20_3LE] = {
 166                 .width = 20, .phys = 24, .le = 1, .signd = 0,
 167                 .silence = { 0x00, 0x00, 0x08 },
 168         },
 169         [SNDRV_PCM_FORMAT_U20_3BE] = {
 170                 .width = 20, .phys = 24, .le = 0, .signd = 0,
 171                 .silence = { 0x08, 0x00, 0x00 },
 172         },
 173         [SNDRV_PCM_FORMAT_S18_3LE] = {
 174                 .width = 18, .phys = 24, .le = 1, .signd = 1,
 175                 .silence = {},
 176         },
 177         [SNDRV_PCM_FORMAT_S18_3BE] = {
 178                 .width = 18, .phys = 24, .le = 0, .signd = 1,
 179                 .silence = {},
 180         },
 181         [SNDRV_PCM_FORMAT_U18_3LE] = {
 182                 .width = 18, .phys = 24, .le = 1, .signd = 0,
 183                 .silence = { 0x00, 0x00, 0x02 },
 184         },
 185         [SNDRV_PCM_FORMAT_U18_3BE] = {
 186                 .width = 18, .phys = 24, .le = 0, .signd = 0,
 187                 .silence = { 0x02, 0x00, 0x00 },
 188         },
 189 };
 190
 191
 192 /**
 193  * snd_pcm_format_signed - Check the PCM format is signed linear
 194  * @format: the format to check
 195  *
 196  * Returns 1 if the given PCM format is signed linear, 0 if unsigned
 197  * linear, and a negative error code for non-linear formats.
 198  */
 199 int snd_pcm_format_signed(snd_pcm_format_t format)
 200 {
 201         int val;
 202         if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 203                 return -EINVAL;
 204         if ((val = pcm_formats[format].signd) < 0)
 205                 return -EINVAL;
 206         return val;
 207 }
 208
 209 EXPORT_SYMBOL(snd_pcm_format_signed);
 210
 211 /**
 212  * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
 213  * @format: the format to check
 214  *
 215  * Returns 1 if the given PCM format is unsigned linear, 0 if signed
 216  * linear, and a negative error code for non-linear formats.
 217  */
 218 int snd_pcm_format_unsigned(snd_pcm_format_t format)
 219 {
 220         int val;
 221
 222         val = snd_pcm_format_signed(format);
 223         if (val < 0)
 224                 return val;
 225         return !val;
 226 }
 227
 228 EXPORT_SYMBOL(snd_pcm_format_unsigned);
 229
 230 /**
 231  * snd_pcm_format_linear - Check the PCM format is linear
 232  * @format: the format to check
 233  *
 234  * Returns 1 if the given PCM format is linear, 0 if not.
 235  */
 236 int snd_pcm_format_linear(snd_pcm_format_t format)
 237 {
 238         return snd_pcm_format_signed(format) >= 0;
 239 }
 240
 241 EXPORT_SYMBOL(snd_pcm_format_linear);
 242
 243 /**
 244  * snd_pcm_format_little_endian - Check the PCM format is little-endian
 245  * @format: the format to check
 246  *
 247  * Returns 1 if the given PCM format is little-endian, 0 if
 248  * big-endian, or a negative error code if endian not specified.
 249  */
 250 int snd_pcm_format_little_endian(snd_pcm_format_t format)
 251 {
 252         int val;
 253         if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 254                 return -EINVAL;
 255         if ((val = pcm_formats[format].le) < 0)
 256                 return -EINVAL;
 257         return val;
 258 }
 259
 260 EXPORT_SYMBOL(snd_pcm_format_little_endian);
 261
 262 /**
 263  * snd_pcm_format_big_endian - Check the PCM format is big-endian
 264  * @format: the format to check
 265  *
 266  * Returns 1 if the given PCM format is big-endian, 0 if
 267  * little-endian, or a negative error code if endian not specified.
 268  */
 269 int snd_pcm_format_big_endian(snd_pcm_format_t format)
 270 {
 271         int val;
 272
 273         val = snd_pcm_format_little_endian(format);
 274         if (val < 0)
 275                 return val;
 276         return !val;
 277 }
 278
 279 EXPORT_SYMBOL(snd_pcm_format_big_endian);
 280
 281 /**
 282  * snd_pcm_format_width - return the bit-width of the format
 283  * @format: the format to check
 284  *
 285  * Returns the bit-width of the format, or a negative error code
 286  * if unknown format.
 287  */
 288 int snd_pcm_format_width(snd_pcm_format_t format)
 289 {
 290         int val;
 291         if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 292                 return -EINVAL;
 293         if ((val = pcm_formats[format].width) == 0)
 294                 return -EINVAL;
 295         return val;
 296 }
 297
 298 EXPORT_SYMBOL(snd_pcm_format_width);
 299
 300 /**
 301  * snd_pcm_format_physical_width - return the physical bit-width of the format
 302  * @format: the format to check
 303  *
 304  * Returns the physical bit-width of the format, or a negative error code
 305  * if unknown format.
 306  */
 307 int snd_pcm_format_physical_width(snd_pcm_format_t format)
 308 {
 309         int val;
 310         if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 311                 return -EINVAL;
 312         if ((val = pcm_formats[format].phys) == 0)
 313                 return -EINVAL;
 314         return val;
 315 }
 316
 317 EXPORT_SYMBOL(snd_pcm_format_physical_width);
 318
 319 /**
 320  * snd_pcm_format_size - return the byte size of samples on the given format
 321  * @format: the format to check
 322  * @samples: sampling rate
 323  *
 324  * Returns the byte size of the given samples for the format, or a
 325  * negative error code if unknown format.
 326  */
 327 ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
 328 {
 329         int phys_width = snd_pcm_format_physical_width(format);
 330         if (phys_width < 0)
 331                 return -EINVAL;
 332         return samples * phys_width / 8;
 333 }
 334
 335 EXPORT_SYMBOL(snd_pcm_format_size);
 336
 337 /**
 338  * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
 339  * @format: the format to check
 340  *
 341  * Returns the format pattern to fill or NULL if error.
 342  */
 343 const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
 344 {
 345         if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 346                 return NULL;
 347         if (! pcm_formats[format].phys)
 348                 return NULL;
 349         return pcm_formats[format].silence;
 350 }
 351
 352 EXPORT_SYMBOL(snd_pcm_format_silence_64);
 353
 354 /**
 355  * snd_pcm_format_set_silence - set the silence data on the buffer
 356  * @format: the PCM format
 357  * @data: the buffer pointer
 358  * @samples: the number of samples to set silence
 359  *
 360  * Sets the silence data on the buffer for the given samples.
 361  *
 362  * Returns zero if successful, or a negative error code on failure.
 363  */
 364 int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
 365 {
 366         int width;
 367         unsigned char *dst, *pat;
 368
 369         if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 370                 return -EINVAL;
 371         if (samples == 0)
 372                 return 0;
 373         width = pcm_formats[format].phys; /* physical width */
 374         pat = pcm_formats[format].silence;
 375         if (! width)
 376                 return -EINVAL;
 377         /* signed or 1 byte data */
 378         if (pcm_formats[format].signd == 1 || width <= 8) {
 379                 unsigned int bytes = samples * width / 8;
 380                 memset(data, *pat, bytes);
 381                 return 0;
 382         }
 383         /* non-zero samples, fill using a loop */
 384         width /= 8;
 385         dst = data;
 386 #if 0
 387         while (samples--) {
 388                 memcpy(dst, pat, width);
 389                 dst += width;
 390         }
 391 #else
 392         /* a bit optimization for constant width */
 393         switch (width) {
 394         case 2:
 395                 while (samples--) {
 396                         memcpy(dst, pat, 2);
 397                         dst += 2;
 398                 }
 399                 break;
 400         case 3:
 401                 while (samples--) {
 402                         memcpy(dst, pat, 3);
 403                         dst += 3;
 404                 }
 405                 break;
 406         case 4:
 407                 while (samples--) {
 408                         memcpy(dst, pat, 4);
 409                         dst += 4;
 410                 }
 411                 break;
 412         case 8:
 413                 while (samples--) {
 414                         memcpy(dst, pat, 8);
 415                         dst += 8;
 416                 }
 417                 break;
 418         }
 419 #endif
 420         return 0;
 421 }
 422
 423 EXPORT_SYMBOL(snd_pcm_format_set_silence);
 424
 425 /**
 426  * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields
 427  * @runtime: the runtime instance
 428  *
 429  * Determines the rate_min and rate_max fields from the rates bits of
 430  * the given runtime->hw.
 431  *
 432  * Returns zero if successful.
 433  */
 434 int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime)
 435 {
 436         int i;
 437         for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
 438                 if (runtime->hw.rates & (1 << i)) {
 439                         runtime->hw.rate_min = snd_pcm_known_rates.list[i];
 440                         break;
 441                 }
 442         }
 443         for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
 444                 if (runtime->hw.rates & (1 << i)) {
 445                         runtime->hw.rate_max = snd_pcm_known_rates.list[i];
 446                         break;
 447                 }
 448         }
 449         return 0;
 450 }
 451
 452 EXPORT_SYMBOL(snd_pcm_limit_hw_rates);
 453
 454 /**
 455  * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
 456  * @rate: the sample rate to convert
 457  *
 458  * Returns the SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
 459  * SNDRV_PCM_RATE_KNOT for an unknown rate.
 460  */
 461 unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
 462 {
 463         unsigned int i;
 464
 465         for (i = 0; i < snd_pcm_known_rates.count; i++)
 466                 if (snd_pcm_known_rates.list[i] == rate)
 467                         return 1u << i;
 468         return SNDRV_PCM_RATE_KNOT;
 469 }
 470 EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);