linux/sound/core/pcm_misc.c
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   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        /* FIXME: the following three formats are not defined properly yet */
 144        [SNDRV_PCM_FORMAT_MPEG] = {
 145                .le = -1, .signd = -1,
 146        },
 147        [SNDRV_PCM_FORMAT_GSM] = {
 148                .le = -1, .signd = -1,
 149        },
 150        [SNDRV_PCM_FORMAT_SPECIAL] = {
 151                .le = -1, .signd = -1,
 152        },
 153        [SNDRV_PCM_FORMAT_S24_3LE] = {
 154                .width = 24, .phys = 24, .le = 1, .signd = 1,
 155                .silence = {},
 156        },
 157        [SNDRV_PCM_FORMAT_S24_3BE] = {
 158                .width = 24, .phys = 24, .le = 0, .signd = 1,
 159                .silence = {},
 160        },
 161        [SNDRV_PCM_FORMAT_U24_3LE] = {
 162                .width = 24, .phys = 24, .le = 1, .signd = 0,
 163                .silence = { 0x00, 0x00, 0x80 },
 164        },
 165        [SNDRV_PCM_FORMAT_U24_3BE] = {
 166                .width = 24, .phys = 24, .le = 0, .signd = 0,
 167                .silence = { 0x80, 0x00, 0x00 },
 168        },
 169        [SNDRV_PCM_FORMAT_S20_3LE] = {
 170                .width = 20, .phys = 24, .le = 1, .signd = 1,
 171                .silence = {},
 172        },
 173        [SNDRV_PCM_FORMAT_S20_3BE] = {
 174                .width = 20, .phys = 24, .le = 0, .signd = 1,
 175                .silence = {},
 176        },
 177        [SNDRV_PCM_FORMAT_U20_3LE] = {
 178                .width = 20, .phys = 24, .le = 1, .signd = 0,
 179                .silence = { 0x00, 0x00, 0x08 },
 180        },
 181        [SNDRV_PCM_FORMAT_U20_3BE] = {
 182                .width = 20, .phys = 24, .le = 0, .signd = 0,
 183                .silence = { 0x08, 0x00, 0x00 },
 184        },
 185        [SNDRV_PCM_FORMAT_S18_3LE] = {
 186                .width = 18, .phys = 24, .le = 1, .signd = 1,
 187                .silence = {},
 188        },
 189        [SNDRV_PCM_FORMAT_S18_3BE] = {
 190                .width = 18, .phys = 24, .le = 0, .signd = 1,
 191                .silence = {},
 192        },
 193        [SNDRV_PCM_FORMAT_U18_3LE] = {
 194                .width = 18, .phys = 24, .le = 1, .signd = 0,
 195                .silence = { 0x00, 0x00, 0x02 },
 196        },
 197        [SNDRV_PCM_FORMAT_U18_3BE] = {
 198                .width = 18, .phys = 24, .le = 0, .signd = 0,
 199                .silence = { 0x02, 0x00, 0x00 },
 200        },
 201        [SNDRV_PCM_FORMAT_G723_24_1B] = {
 202                .width = 3, .phys = 8, .le = -1, .signd = -1,
 203                .silence = {},
 204        },
 205        [SNDRV_PCM_FORMAT_G723_40_1B] = {
 206                .width = 5, .phys = 8, .le = -1, .signd = -1,
 207                .silence = {},
 208        },
 209};
 210
 211
 212/**
 213 * snd_pcm_format_signed - Check the PCM format is signed linear
 214 * @format: the format to check
 215 *
 216 * Returns 1 if the given PCM format is signed linear, 0 if unsigned
 217 * linear, and a negative error code for non-linear formats.
 218 */
 219int snd_pcm_format_signed(snd_pcm_format_t format)
 220{
 221        int val;
 222        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 223                return -EINVAL;
 224        if ((val = pcm_formats[(INT)format].signd) < 0)
 225                return -EINVAL;
 226        return val;
 227}
 228
 229EXPORT_SYMBOL(snd_pcm_format_signed);
 230
 231/**
 232 * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
 233 * @format: the format to check
 234 *
 235 * Returns 1 if the given PCM format is unsigned linear, 0 if signed
 236 * linear, and a negative error code for non-linear formats.
 237 */
 238int snd_pcm_format_unsigned(snd_pcm_format_t format)
 239{
 240        int val;
 241
 242        val = snd_pcm_format_signed(format);
 243        if (val < 0)
 244                return val;
 245        return !val;
 246}
 247
 248EXPORT_SYMBOL(snd_pcm_format_unsigned);
 249
 250/**
 251 * snd_pcm_format_linear - Check the PCM format is linear
 252 * @format: the format to check
 253 *
 254 * Returns 1 if the given PCM format is linear, 0 if not.
 255 */
 256int snd_pcm_format_linear(snd_pcm_format_t format)
 257{
 258        return snd_pcm_format_signed(format) >= 0;
 259}
 260
 261EXPORT_SYMBOL(snd_pcm_format_linear);
 262
 263/**
 264 * snd_pcm_format_little_endian - Check the PCM format is little-endian
 265 * @format: the format to check
 266 *
 267 * Returns 1 if the given PCM format is little-endian, 0 if
 268 * big-endian, or a negative error code if endian not specified.
 269 */
 270int snd_pcm_format_little_endian(snd_pcm_format_t format)
 271{
 272        int val;
 273        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 274                return -EINVAL;
 275        if ((val = pcm_formats[(INT)format].le) < 0)
 276                return -EINVAL;
 277        return val;
 278}
 279
 280EXPORT_SYMBOL(snd_pcm_format_little_endian);
 281
 282/**
 283 * snd_pcm_format_big_endian - Check the PCM format is big-endian
 284 * @format: the format to check
 285 *
 286 * Returns 1 if the given PCM format is big-endian, 0 if
 287 * little-endian, or a negative error code if endian not specified.
 288 */
 289int snd_pcm_format_big_endian(snd_pcm_format_t format)
 290{
 291        int val;
 292
 293        val = snd_pcm_format_little_endian(format);
 294        if (val < 0)
 295                return val;
 296        return !val;
 297}
 298
 299EXPORT_SYMBOL(snd_pcm_format_big_endian);
 300
 301/**
 302 * snd_pcm_format_width - return the bit-width of the format
 303 * @format: the format to check
 304 *
 305 * Returns the bit-width of the format, or a negative error code
 306 * if unknown format.
 307 */
 308int snd_pcm_format_width(snd_pcm_format_t format)
 309{
 310        int val;
 311        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 312                return -EINVAL;
 313        if ((val = pcm_formats[(INT)format].width) == 0)
 314                return -EINVAL;
 315        return val;
 316}
 317
 318EXPORT_SYMBOL(snd_pcm_format_width);
 319
 320/**
 321 * snd_pcm_format_physical_width - return the physical bit-width of the format
 322 * @format: the format to check
 323 *
 324 * Returns the physical bit-width of the format, or a negative error code
 325 * if unknown format.
 326 */
 327int snd_pcm_format_physical_width(snd_pcm_format_t format)
 328{
 329        int val;
 330        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 331                return -EINVAL;
 332        if ((val = pcm_formats[(INT)format].phys) == 0)
 333                return -EINVAL;
 334        return val;
 335}
 336
 337EXPORT_SYMBOL(snd_pcm_format_physical_width);
 338
 339/**
 340 * snd_pcm_format_size - return the byte size of samples on the given format
 341 * @format: the format to check
 342 * @samples: sampling rate
 343 *
 344 * Returns the byte size of the given samples for the format, or a
 345 * negative error code if unknown format.
 346 */
 347ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
 348{
 349        int phys_width = snd_pcm_format_physical_width(format);
 350        if (phys_width < 0)
 351                return -EINVAL;
 352        return samples * phys_width / 8;
 353}
 354
 355EXPORT_SYMBOL(snd_pcm_format_size);
 356
 357/**
 358 * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
 359 * @format: the format to check
 360 *
 361 * Returns the format pattern to fill or NULL if error.
 362 */
 363const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
 364{
 365        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 366                return NULL;
 367        if (! pcm_formats[(INT)format].phys)
 368                return NULL;
 369        return pcm_formats[(INT)format].silence;
 370}
 371
 372EXPORT_SYMBOL(snd_pcm_format_silence_64);
 373
 374/**
 375 * snd_pcm_format_set_silence - set the silence data on the buffer
 376 * @format: the PCM format
 377 * @data: the buffer pointer
 378 * @samples: the number of samples to set silence
 379 *
 380 * Sets the silence data on the buffer for the given samples.
 381 *
 382 * Returns zero if successful, or a negative error code on failure.
 383 */
 384int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
 385{
 386        int width;
 387        unsigned char *dst, *pat;
 388
 389        if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
 390                return -EINVAL;
 391        if (samples == 0)
 392                return 0;
 393        width = pcm_formats[(INT)format].phys; /* physical width */
 394        pat = pcm_formats[(INT)format].silence;
 395        if (! width)
 396                return -EINVAL;
 397        /* signed or 1 byte data */
 398        if (pcm_formats[(INT)format].signd == 1 || width <= 8) {
 399                unsigned int bytes = samples * width / 8;
 400                memset(data, *pat, bytes);
 401                return 0;
 402        }
 403        /* non-zero samples, fill using a loop */
 404        width /= 8;
 405        dst = data;
 406#if 0
 407        while (samples--) {
 408                memcpy(dst, pat, width);
 409                dst += width;
 410        }
 411#else
 412        /* a bit optimization for constant width */
 413        switch (width) {
 414        case 2:
 415                while (samples--) {
 416                        memcpy(dst, pat, 2);
 417                        dst += 2;
 418                }
 419                break;
 420        case 3:
 421                while (samples--) {
 422                        memcpy(dst, pat, 3);
 423                        dst += 3;
 424                }
 425                break;
 426        case 4:
 427                while (samples--) {
 428                        memcpy(dst, pat, 4);
 429                        dst += 4;
 430                }
 431                break;
 432        case 8:
 433                while (samples--) {
 434                        memcpy(dst, pat, 8);
 435                        dst += 8;
 436                }
 437                break;
 438        }
 439#endif
 440        return 0;
 441}
 442
 443EXPORT_SYMBOL(snd_pcm_format_set_silence);
 444
 445/**
 446 * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields
 447 * @runtime: the runtime instance
 448 *
 449 * Determines the rate_min and rate_max fields from the rates bits of
 450 * the given runtime->hw.
 451 *
 452 * Returns zero if successful.
 453 */
 454int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime)
 455{
 456        int i;
 457        for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
 458                if (runtime->hw.rates & (1 << i)) {
 459                        runtime->hw.rate_min = snd_pcm_known_rates.list[i];
 460                        break;
 461                }
 462        }
 463        for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
 464                if (runtime->hw.rates & (1 << i)) {
 465                        runtime->hw.rate_max = snd_pcm_known_rates.list[i];
 466                        break;
 467                }
 468        }
 469        return 0;
 470}
 471
 472EXPORT_SYMBOL(snd_pcm_limit_hw_rates);
 473
 474/**
 475 * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
 476 * @rate: the sample rate to convert
 477 *
 478 * Returns the SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
 479 * SNDRV_PCM_RATE_KNOT for an unknown rate.
 480 */
 481unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
 482{
 483        unsigned int i;
 484
 485        for (i = 0; i < snd_pcm_known_rates.count; i++)
 486                if (snd_pcm_known_rates.list[i] == rate)
 487                        return 1u << i;
 488        return SNDRV_PCM_RATE_KNOT;
 489}
 490EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);
 491
 492/**
 493 * snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate
 494 * @rate_bit: the rate bit to convert
 495 *
 496 * Returns the sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag
 497 * or 0 for an unknown rate bit
 498 */
 499unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit)
 500{
 501        unsigned int i;
 502
 503        for (i = 0; i < snd_pcm_known_rates.count; i++)
 504                if ((1u << i) == rate_bit)
 505                        return snd_pcm_known_rates.list[i];
 506        return 0;
 507}
 508EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate);
 509
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