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 <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 */
  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
  39static 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 */
 200int 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
 210EXPORT_SYMBOL(snd_pcm_format_signed);
 211
 212/**
 213 * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
 214 * @format: the format to check
 215 *
 216 * Returns 1 if the given PCM format is unsigned linear, 0 if signed
 217 * linear, and a negative error code for non-linear formats.
 218 */
 219int snd_pcm_format_unsigned(snd_pcm_format_t format)
 220{
 221        int val;
 222
 223        val = snd_pcm_format_signed(format);
 224        if (val < 0)
 225                return val;
 226        return !val;
 227}
 228
 229EXPORT_SYMBOL(snd_pcm_format_unsigned);
 230
 231/**
 232 * snd_pcm_format_linear - Check the PCM format is linear
 233 * @format: the format to check
 234 *
 235 * Returns 1 if the given PCM format is linear, 0 if not.
 236 */
 237int snd_pcm_format_linear(snd_pcm_format_t format)
 238{
 239        return snd_pcm_format_signed(format) >= 0;
 240}
 241
 242EXPORT_SYMBOL(snd_pcm_format_linear);
 243
 244/**
 245 * snd_pcm_format_little_endian - Check the PCM format is little-endian
 246 * @format: the format to check
 247 *
 248 * Returns 1 if the given PCM format is little-endian, 0 if
 249 * big-endian, or a negative error code if endian not specified.
 250 */
 251int snd_pcm_format_little_endian(snd_pcm_format_t format)
 252{
 253        int val;
 254        if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 255                return -EINVAL;
 256        if ((val = pcm_formats[format].le) < 0)
 257                return -EINVAL;
 258        return val;
 259}
 260
 261EXPORT_SYMBOL(snd_pcm_format_little_endian);
 262
 263/**
 264 * snd_pcm_format_big_endian - Check the PCM format is big-endian
 265 * @format: the format to check
 266 *
 267 * Returns 1 if the given PCM format is big-endian, 0 if
 268 * little-endian, or a negative error code if endian not specified.
 269 */
 270int snd_pcm_format_big_endian(snd_pcm_format_t format)
 271{
 272        int val;
 273
 274        val = snd_pcm_format_little_endian(format);
 275        if (val < 0)
 276                return val;
 277        return !val;
 278}
 279
 280EXPORT_SYMBOL(snd_pcm_format_big_endian);
 281
 282/**
 283 * snd_pcm_format_width - return the bit-width of the format
 284 * @format: the format to check
 285 *
 286 * Returns the bit-width of the format, or a negative error code
 287 * if unknown format.
 288 */
 289int snd_pcm_format_width(snd_pcm_format_t format)
 290{
 291        int val;
 292        if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 293                return -EINVAL;
 294        if ((val = pcm_formats[format].width) == 0)
 295                return -EINVAL;
 296        return val;
 297}
 298
 299EXPORT_SYMBOL(snd_pcm_format_width);
 300
 301/**
 302 * snd_pcm_format_physical_width - return the physical bit-width of the format
 303 * @format: the format to check
 304 *
 305 * Returns the physical bit-width of the format, or a negative error code
 306 * if unknown format.
 307 */
 308int snd_pcm_format_physical_width(snd_pcm_format_t format)
 309{
 310        int val;
 311        if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
 312                return -EINVAL;
 313        if ((val = pcm_formats[format].phys) == 0)
 314                return -EINVAL;
 315        return val;
 316}
 317
 318EXPORT_SYMBOL(snd_pcm_format_physical_width);
 319
 320/**
 321 * snd_pcm_format_size - return the byte size of samples on the given format
 322 * @format: the format to check
 323 *
 324 * Returns the byte size of the given samples for the format, or a
 325 * negative error code if unknown format.
 326 */
 327ssize_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
 335EXPORT_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 */
 343const 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
 352EXPORT_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 */
 364int 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
 423EXPORT_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 */
 434int 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
 452EXPORT_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 */
 461unsigned 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}
 470EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);
 471