LXR linux/sound/core/pcm

   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 <linux/export.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 */
  31struct 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/* we do lots of calculations on snd_pcm_format_t; shut up sparse */
  40#define INT     __force int
  41
  42static struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = {
  43        [SNDRV_PCM_FORMAT_S8] = {
  44                .width = 8, .phys = 8, .le = -1, .signd = 1,
  45                .silence = {},
  46        },
  47        [SNDRV_PCM_FORMAT_U8] = {
  48                .width = 8, .phys = 8, .le = -1, .signd = 0,
  49                .silence = { 0x80 },
  50        },
  51        [SNDRV_PCM_FORMAT_S16_LE] = {
  52                .width = 16, .phys = 16, .le = 1, .signd = 1,
  53                .silence = {},
  54        },
  55        [SNDRV_PCM_FORMAT_S16_BE] = {
  56                .width = 16, .phys = 16, .le = 0, .signd = 1,
  57                .silence = {},
  58        },
  59        [SNDRV_PCM_FORMAT_U16_LE] = {
  60                .width = 16, .phys = 16, .le = 1, .signd = 0,
  61                .silence = { 0x00, 0x80 },
  62        },
  63        [SNDRV_PCM_FORMAT_U16_BE] = {
  64                .width = 16, .phys = 16, .le = 0, .signd = 0,
  65                .silence = { 0x80, 0x00 },
  66        },
  67        [SNDRV_PCM_FORMAT_S24_LE] = {
  68                .width = 24, .phys = 32, .le = 1, .signd = 1,
  69                .silence = {},
  70        },
  71        [SNDRV_PCM_FORMAT_S24_BE] = {
  72                .width = 24, .phys = 32, .le = 0, .signd = 1,
  73                .silence = {},
  74        },
  75        [SNDRV_PCM_FORMAT_U24_LE] = {
  76                .width = 24, .phys = 32, .le = 1, .signd = 0,
  77                .silence = { 0x00, 0x00, 0x80 },
  78        },
  79        [SNDRV_PCM_FORMAT_U24_BE] = {
  80                .width = 24, .phys = 32, .le = 0, .signd = 0,
  81                .silence = { 0x00, 0x80, 0x00, 0x00 },
  82        },
  83        [SNDRV_PCM_FORMAT_S32_LE] = {
  84                .width = 32, .phys = 32, .le = 1, .signd = 1,
  85                .silence = {},
  86        },
  87        [SNDRV_PCM_FORMAT_S32_BE] = {
  88                .width = 32, .phys = 32, .le = 0, .signd = 1,
  89                .silence = {},
  90        },
  91        [SNDRV_PCM_FORMAT_U32_LE] = {
  92                .width = 32, .phys = 32, .le = 1, .signd = 0,
  93                .silence = { 0x00, 0x00, 0x00, 0x80 },
  94        },
  95        [SNDRV_PCM_FORMAT_U32_BE] = {
  96                .width = 32, .phys = 32, .le = 0, .signd = 0,
  97                .silence = { 0x80, 0x00, 0x00, 0x00 },
  98        },
  99        [SNDRV_PCM_FORMAT_FLOAT_LE] = {
 100                .width = 32, .phys = 32, .le = 1, .signd = -1,
 101                .silence = {},
 102        },
 103        [SNDRV_PCM_FORMAT_FLOAT_BE] = {
 104                .width = 32, .phys = 32, .le = 0, .signd = -1,
 105                .silence = {},
 106        },
 107        [SNDRV_PCM_FORMAT_FLOAT64_LE] = {
 108                .width = 64, .phys = 64, .le = 1, .signd = -1,
 109                .silence = {},
 110        },
 111        [SNDRV_PCM_FORMAT_FLOAT64_BE] = {
 112                .width = 64, .phys = 64, .le = 0, .signd = -1,
 113                .silence = {},
 114        },
 115        [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
 116                .width = 32, .phys = 32, .le = 1, .signd = -1,
 117                .silence = {},
 118        },
 119        [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
 120                .width = 32, .phys = 32, .le = 0, .signd = -1,
 121                .silence = {},
 122        },
 123        [SNDRV_PCM_FORMAT_MU_LAW] = {
 124                .width = 8, .phys = 8, .le = -1, .signd = -1,
 125                .silence = { 0x7f },
 126        },
 127        [SNDRV_PCM_FORMAT_A_LAW] = {
 128                .width = 8, .phys = 8, .le = -1, .signd = -1,
 129                .silence = { 0x55 },
 130        },
 131        [SNDRV_PCM_FORMAT_IMA_ADPCM] = {
 132                .width = 4, .phys = 4, .le = -1, .signd = -1,
 133                .silence = {},
 134        },
 135        [SNDRV_PCM_FORMAT_G723_24] = {
 136                .width = 3, .phys = 3, .le = -1, .signd = -1,
 137                .silence = {},
 138        },
 139        [SNDRV_PCM_FORMAT_G723_40] = {
 140                .width = 5, .phys = 5, .le = -1, .signd = -1,
 141                .silence = {},
 142        },
 143        [SNDRV_PCM_FORMAT_DSD_U8] = {
 144                .width = 8, .phys = 8, .le = 1, .signd = 0,
 145                .silence = { 0x69 },
 146        },
 147        [SNDRV_PCM_FORMAT_DSD_U16_LE] = {
 148                .width = 16, .phys = 16, .le = 1, .signd = 0,
 149                .silence = { 0x69, 0x69 },
 150        },
 151        [SNDRV_PCM_FORMAT_DSD_U32_LE] = {
 152                .width = 32, .phys = 32, .le = 1, .signd = 0,
 153                .silence = { 0x69, 0x69, 0x69, 0x69 },
 154        },
 155        [SNDRV_PCM_FORMAT_DSD_U16_BE] = {
 156                .width = 16, .phys = 16, .le = 0, .signd = 0,
 157                .silence = { 0x69, 0x69 },
 158        },
 159        [SNDRV_PCM_FORMAT_DSD_U32_BE] = {
 160                .width = 32, .phys = 32, .le = 0, .signd = 0,
 161                .silence = { 0x69, 0x69, 0x69, 0x69 },
 162        },
 163        /* FIXME: the following three formats are not defined properly yet */
 164        [SNDRV_PCM_FORMAT_MPEG] = {
 165                .le = -1, .signd = -1,
 166        },
 167        [SNDRV_PCM_FORMAT_GSM] = {
 168                .le = -1, .signd = -1,
 169        },
 170        [SNDRV_PCM_FORMAT_SPECIAL] = {
 171                .le = -1, .signd = -1,
 172        },
 173        [SNDRV_PCM_FORMAT_S24_3LE] = {
 174                .width = 24, .phys = 24, .le = 1, .signd = 1,
 175                .silence = {},
 176        },
 177        [SNDRV_PCM_FORMAT_S24_3BE] = {
 178                .width = 24, .phys = 24, .le = 0, .signd = 1,
 179                .silence = {},
 180        },
 181        [SNDRV_PCM_FORMAT_U24_3LE] = {
 182                .width = 24, .phys = 24, .le = 1, .signd = 0,
 183                .silence = { 0x00, 0x00, 0x80 },
 184        },
 185        [SNDRV_PCM_FORMAT_U24_3BE] = {
 186                .width = 24, .phys = 24, .le = 0, .signd = 0,
 187                .silence = { 0x80, 0x00, 0x00 },
 188        },
 189        [SNDRV_PCM_FORMAT_S20_3LE] = {
 190                .width = 20, .phys = 24, .le = 1, .signd = 1,
 191                .silence = {},
 192        },
 193        [SNDRV_PCM_FORMAT_S20_3BE] = {
 194                .width = 20, .phys = 24, .le = 0, .signd = 1,
 195                .silence = {},
 196        },
 197        [SNDRV_PCM_FORMAT_U20_3LE] = {
 198                .width = 20, .phys = 24, .le = 1, .signd = 0,
 199                .silence = { 0x00, 0x00, 0x08 },
 200        },
 201        [SNDRV_PCM_FORMAT_U20_3BE] = {
 202                .width = 20, .phys = 24, .le = 0, .signd = 0,
 203                .silence = { 0x08, 0x00, 0x00 },
 204        },
 205        [SNDRV_PCM_FORMAT_S18_3LE] = {
 206                .width = 18, .phys = 24, .le = 1, .signd = 1,
 207                .silence = {},
 208        },
 209        [SNDRV_PCM_FORMAT_S18_3BE] = {
 210                .width = 18, .phys = 24, .le = 0, .signd = 1,
 211                .silence = {},
 212        },
 213        [SNDRV_PCM_FORMAT_U18_3LE] = {
 214                .width = 18, .phys = 24, .le = 1, .signd = 0,
 215                .silence = { 0x00, 0x00, 0x02 },
 216        },
 217        [SNDRV_PCM_FORMAT_U18_3BE] = {
 218                .width = 18, .phys = 24, .le = 0, .signd = 0,
 219                .silence = { 0x02, 0x00, 0x00 },
 220        },
 221        [SNDRV_PCM_FORMAT_G723_24_1B] = {
 222                .width = 3, .phys = 8, .le = -1, .signd = -1,
 223                .silence = {},
 224        },
 225        [SNDRV_PCM_FORMAT_G723_40_1B] = {
 226                .width = 5, .phys = 8, .le = -1, .signd = -1,
 227                .silence = {},
 228        },
 229};
 230
 231
 232/**
 233 * snd_pcm_format_signed - Check the PCM format is signed linear
 234 * @format: the format to check
 235 *
 236 * Return: 1 if the given PCM format is signed linear, 0 if unsigned
 237 * linear, and a negative error code for non-linear formats.
 238 */
 239int snd_pcm_format_signed(snd_pcm_format_t format)
 240{
 241        int val;
 242        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 243                return -EINVAL;
 244        if ((val = pcm_formats[(INT)format].signd) < 0)
 245                return -EINVAL;
 246        return val;
 247}
 248
 249EXPORT_SYMBOL(snd_pcm_format_signed);
 250
 251/**
 252 * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
 253 * @format: the format to check
 254 *
 255 * Return: 1 if the given PCM format is unsigned linear, 0 if signed
 256 * linear, and a negative error code for non-linear formats.
 257 */
 258int snd_pcm_format_unsigned(snd_pcm_format_t format)
 259{
 260        int val;
 261
 262        val = snd_pcm_format_signed(format);
 263        if (val < 0)
 264                return val;
 265        return !val;
 266}
 267
 268EXPORT_SYMBOL(snd_pcm_format_unsigned);
 269
 270/**
 271 * snd_pcm_format_linear - Check the PCM format is linear
 272 * @format: the format to check
 273 *
 274 * Return: 1 if the given PCM format is linear, 0 if not.
 275 */
 276int snd_pcm_format_linear(snd_pcm_format_t format)
 277{
 278        return snd_pcm_format_signed(format) >= 0;
 279}
 280
 281EXPORT_SYMBOL(snd_pcm_format_linear);
 282
 283/**
 284 * snd_pcm_format_little_endian - Check the PCM format is little-endian
 285 * @format: the format to check
 286 *
 287 * Return: 1 if the given PCM format is little-endian, 0 if
 288 * big-endian, or a negative error code if endian not specified.
 289 */
 290int snd_pcm_format_little_endian(snd_pcm_format_t format)
 291{
 292        int val;
 293        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 294                return -EINVAL;
 295        if ((val = pcm_formats[(INT)format].le) < 0)
 296                return -EINVAL;
 297        return val;
 298}
 299
 300EXPORT_SYMBOL(snd_pcm_format_little_endian);
 301
 302/**
 303 * snd_pcm_format_big_endian - Check the PCM format is big-endian
 304 * @format: the format to check
 305 *
 306 * Return: 1 if the given PCM format is big-endian, 0 if
 307 * little-endian, or a negative error code if endian not specified.
 308 */
 309int snd_pcm_format_big_endian(snd_pcm_format_t format)
 310{
 311        int val;
 312
 313        val = snd_pcm_format_little_endian(format);
 314        if (val < 0)
 315                return val;
 316        return !val;
 317}
 318
 319EXPORT_SYMBOL(snd_pcm_format_big_endian);
 320
 321/**
 322 * snd_pcm_format_width - return the bit-width of the format
 323 * @format: the format to check
 324 *
 325 * Return: The bit-width of the format, or a negative error code
 326 * if unknown format.
 327 */
 328int snd_pcm_format_width(snd_pcm_format_t format)
 329{
 330        int val;
 331        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 332                return -EINVAL;
 333        if ((val = pcm_formats[(INT)format].width) == 0)
 334                return -EINVAL;
 335        return val;
 336}
 337
 338EXPORT_SYMBOL(snd_pcm_format_width);
 339
 340/**
 341 * snd_pcm_format_physical_width - return the physical bit-width of the format
 342 * @format: the format to check
 343 *
 344 * Return: The physical bit-width of the format, or a negative error code
 345 * if unknown format.
 346 */
 347int snd_pcm_format_physical_width(snd_pcm_format_t format)
 348{
 349        int val;
 350        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 351                return -EINVAL;
 352        if ((val = pcm_formats[(INT)format].phys) == 0)
 353                return -EINVAL;
 354        return val;
 355}
 356
 357EXPORT_SYMBOL(snd_pcm_format_physical_width);
 358
 359/**
 360 * snd_pcm_format_size - return the byte size of samples on the given format
 361 * @format: the format to check
 362 * @samples: sampling rate
 363 *
 364 * Return: The byte size of the given samples for the format, or a
 365 * negative error code if unknown format.
 366 */
 367ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
 368{
 369        int phys_width = snd_pcm_format_physical_width(format);
 370        if (phys_width < 0)
 371                return -EINVAL;
 372        return samples * phys_width / 8;
 373}
 374
 375EXPORT_SYMBOL(snd_pcm_format_size);
 376
 377/**
 378 * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
 379 * @format: the format to check
 380 *
 381 * Return: The format pattern to fill or %NULL if error.
 382 */
 383const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
 384{
 385        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 386                return NULL;
 387        if (! pcm_formats[(INT)format].phys)
 388                return NULL;
 389        return pcm_formats[(INT)format].silence;
 390}
 391
 392EXPORT_SYMBOL(snd_pcm_format_silence_64);
 393
 394/**
 395 * snd_pcm_format_set_silence - set the silence data on the buffer
 396 * @format: the PCM format
 397 * @data: the buffer pointer
 398 * @samples: the number of samples to set silence
 399 *
 400 * Sets the silence data on the buffer for the given samples.
 401 *
 402 * Return: Zero if successful, or a negative error code on failure.
 403 */
 404int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
 405{
 406        int width;
 407        unsigned char *dst, *pat;
 408
 409        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 410                return -EINVAL;
 411        if (samples == 0)
 412                return 0;
 413        width = pcm_formats[(INT)format].phys; /* physical width */
 414        pat = pcm_formats[(INT)format].silence;
 415        if (! width)
 416                return -EINVAL;
 417        /* signed or 1 byte data */
 418        if (pcm_formats[(INT)format].signd == 1 || width <= 8) {
 419                unsigned int bytes = samples * width / 8;
 420                memset(data, *pat, bytes);
 421                return 0;
 422        }
 423        /* non-zero samples, fill using a loop */
 424        width /= 8;
 425        dst = data;
 426#if 0
 427        while (samples--) {
 428                memcpy(dst, pat, width);
 429                dst += width;
 430        }
 431#else
 432        /* a bit optimization for constant width */
 433        switch (width) {
 434        case 2:
 435                while (samples--) {
 436                        memcpy(dst, pat, 2);
 437                        dst += 2;
 438                }
 439                break;
 440        case 3:
 441                while (samples--) {
 442                        memcpy(dst, pat, 3);
 443                        dst += 3;
 444                }
 445                break;
 446        case 4:
 447                while (samples--) {
 448                        memcpy(dst, pat, 4);
 449                        dst += 4;
 450                }
 451                break;
 452        case 8:
 453                while (samples--) {
 454                        memcpy(dst, pat, 8);
 455                        dst += 8;
 456                }
 457                break;
 458        }
 459#endif
 460        return 0;
 461}
 462
 463EXPORT_SYMBOL(snd_pcm_format_set_silence);
 464
 465/**
 466 * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields
 467 * @runtime: the runtime instance
 468 *
 469 * Determines the rate_min and rate_max fields from the rates bits of
 470 * the given runtime->hw.
 471 *
 472 * Return: Zero if successful.
 473 */
 474int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime)
 475{
 476        int i;
 477        for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
 478                if (runtime->hw.rates & (1 << i)) {
 479                        runtime->hw.rate_min = snd_pcm_known_rates.list[i];
 480                        break;
 481                }
 482        }
 483        for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
 484                if (runtime->hw.rates & (1 << i)) {
 485                        runtime->hw.rate_max = snd_pcm_known_rates.list[i];
 486                        break;
 487                }
 488        }
 489        return 0;
 490}
 491
 492EXPORT_SYMBOL(snd_pcm_limit_hw_rates);
 493
 494/**
 495 * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
 496 * @rate: the sample rate to convert
 497 *
 498 * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
 499 * SNDRV_PCM_RATE_KNOT for an unknown rate.
 500 */
 501unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
 502{
 503        unsigned int i;
 504
 505        for (i = 0; i < snd_pcm_known_rates.count; i++)
 506                if (snd_pcm_known_rates.list[i] == rate)
 507                        return 1u << i;
 508        return SNDRV_PCM_RATE_KNOT;
 509}
 510EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);
 511
 512/**
 513 * snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate
 514 * @rate_bit: the rate bit to convert
 515 *
 516 * Return: The sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag
 517 * or 0 for an unknown rate bit.
 518 */
 519unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit)
 520{
 521        unsigned int i;
 522
 523        for (i = 0; i < snd_pcm_known_rates.count; i++)
 524                if ((1u << i) == rate_bit)
 525                        return snd_pcm_known_rates.list[i];
 526        return 0;
 527}
 528EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate);
 529
 530static unsigned int snd_pcm_rate_mask_sanitize(unsigned int rates)
 531{
 532        if (rates & SNDRV_PCM_RATE_CONTINUOUS)
 533                return SNDRV_PCM_RATE_CONTINUOUS;
 534        else if (rates & SNDRV_PCM_RATE_KNOT)
 535                return SNDRV_PCM_RATE_KNOT;
 536        return rates;
 537}
 538
 539/**
 540 * snd_pcm_rate_mask_intersect - computes the intersection between two rate masks
 541 * @rates_a: The first rate mask
 542 * @rates_b: The second rate mask
 543 *
 544 * This function computes the rates that are supported by both rate masks passed
 545 * to the function. It will take care of the special handling of
 546 * SNDRV_PCM_RATE_CONTINUOUS and SNDRV_PCM_RATE_KNOT.
 547 *
 548 * Return: A rate mask containing the rates that are supported by both rates_a
 549 * and rates_b.
 550 */
 551unsigned int snd_pcm_rate_mask_intersect(unsigned int rates_a,
 552        unsigned int rates_b)
 553{
 554        rates_a = snd_pcm_rate_mask_sanitize(rates_a);
 555        rates_b = snd_pcm_rate_mask_sanitize(rates_b);
 556
 557        if (rates_a & SNDRV_PCM_RATE_CONTINUOUS)
 558                return rates_b;
 559        else if (rates_b & SNDRV_PCM_RATE_CONTINUOUS)
 560                return rates_a;
 561        else if (rates_a & SNDRV_PCM_RATE_KNOT)
 562                return rates_b;
 563        else if (rates_b & SNDRV_PCM_RATE_KNOT)
 564                return rates_a;
 565        return rates_a & rates_b;
 566}
 567EXPORT_SYMBOL_GPL(snd_pcm_rate_mask_intersect);
 568
 569/**
 570 * snd_pcm_rate_range_to_bits - converts rate range to SNDRV_PCM_RATE_xxx bit
 571 * @rate_min: the minimum sample rate
 572 * @rate_max: the maximum sample rate
 573 *
 574 * This function has an implicit assumption: the rates in the given range have
 575 * only the pre-defined rates like 44100 or 16000.
 576 *
 577 * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate range,
 578 * or SNDRV_PCM_RATE_KNOT for an unknown range.
 579 */
 580unsigned int snd_pcm_rate_range_to_bits(unsigned int rate_min,
 581        unsigned int rate_max)
 582{
 583        unsigned int rates = 0;
 584        int i;
 585
 586        for (i = 0; i < snd_pcm_known_rates.count; i++) {
 587                if (snd_pcm_known_rates.list[i] >= rate_min
 588                        && snd_pcm_known_rates.list[i] <= rate_max)
 589                        rates |= 1 << i;
 590        }
 591
 592        if (!rates)
 593                rates = SNDRV_PCM_RATE_KNOT;
 594
 595        return rates;
 596}
 597EXPORT_SYMBOL_GPL(snd_pcm_rate_range_to_bits);
 598