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 [SNDRV_PCM_FORMAT_G723_24] = { 132 .width = 3, .phys = 3, .le = -1, .signd = -1, 133 .silence = {}, 134 }, 135 [SNDRV_PCM_FORMAT_G723_40] = { 136 .width = 5, .phys = 5, .le = -1, .signd = -1, 137 .silence = {}, 138 }, 139 /* FIXME: the following three formats are not defined properly yet */ 140 [SNDRV_PCM_FORMAT_MPEG] = { 141 .le = -1, .signd = -1, 142 }, 143 [SNDRV_PCM_FORMAT_GSM] = { 144 .le = -1, .signd = -1, 145 }, 146 [SNDRV_PCM_FORMAT_SPECIAL] = { 147 .le = -1, .signd = -1, 148 }, 149 [SNDRV_PCM_FORMAT_S24_3LE] = { 150 .width = 24, .phys = 24, .le = 1, .signd = 1, 151 .silence = {}, 152 }, 153 [SNDRV_PCM_FORMAT_S24_3BE] = { 154 .width = 24, .phys = 24, .le = 0, .signd = 1, 155 .silence = {}, 156 }, 157 [SNDRV_PCM_FORMAT_U24_3LE] = { 158 .width = 24, .phys = 24, .le = 1, .signd = 0, 159 .silence = { 0x00, 0x00, 0x80 }, 160 }, 161 [SNDRV_PCM_FORMAT_U24_3BE] = { 162 .width = 24, .phys = 24, .le = 0, .signd = 0, 163 .silence = { 0x80, 0x00, 0x00 }, 164 }, 165 [SNDRV_PCM_FORMAT_S20_3LE] = { 166 .width = 20, .phys = 24, .le = 1, .signd = 1, 167 .silence = {}, 168 }, 169 [SNDRV_PCM_FORMAT_S20_3BE] = { 170 .width = 20, .phys = 24, .le = 0, .signd = 1, 171 .silence = {}, 172 }, 173 [SNDRV_PCM_FORMAT_U20_3LE] = { 174 .width = 20, .phys = 24, .le = 1, .signd = 0, 175 .silence = { 0x00, 0x00, 0x08 }, 176 }, 177 [SNDRV_PCM_FORMAT_U20_3BE] = { 178 .width = 20, .phys = 24, .le = 0, .signd = 0, 179 .silence = { 0x08, 0x00, 0x00 }, 180 }, 181 [SNDRV_PCM_FORMAT_S18_3LE] = { 182 .width = 18, .phys = 24, .le = 1, .signd = 1, 183 .silence = {}, 184 }, 185 [SNDRV_PCM_FORMAT_S18_3BE] = { 186 .width = 18, .phys = 24, .le = 0, .signd = 1, 187 .silence = {}, 188 }, 189 [SNDRV_PCM_FORMAT_U18_3LE] = { 190 .width = 18, .phys = 24, .le = 1, .signd = 0, 191 .silence = { 0x00, 0x00, 0x02 }, 192 }, 193 [SNDRV_PCM_FORMAT_U18_3BE] = { 194 .width = 18, .phys = 24, .le = 0, .signd = 0, 195 .silence = { 0x02, 0x00, 0x00 }, 196 }, 197 [SNDRV_PCM_FORMAT_G723_24_1B] = { 198 .width = 3, .phys = 8, .le = -1, .signd = -1, 199 .silence = {}, 200 }, 201 [SNDRV_PCM_FORMAT_G723_40_1B] = { 202 .width = 5, .phys = 8, .le = -1, .signd = -1, 203 .silence = {}, 204 }, 205 }; 206 207 208 /** 209 * snd_pcm_format_signed - Check the PCM format is signed linear 210 * @format: the format to check 211 * 212 * Returns 1 if the given PCM format is signed linear, 0 if unsigned 213 * linear, and a negative error code for non-linear formats. 214 */ 215 int snd_pcm_format_signed(snd_pcm_format_t format) 216 { 217 int val; 218 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 219 return -EINVAL; 220 if ((val = pcm_formats[format].signd) < 0) 221 return -EINVAL; 222 return val; 223 } 224 225 EXPORT_SYMBOL(snd_pcm_format_signed); 226 227 /** 228 * snd_pcm_format_unsigned - Check the PCM format is unsigned linear 229 * @format: the format to check 230 * 231 * Returns 1 if the given PCM format is unsigned linear, 0 if signed 232 * linear, and a negative error code for non-linear formats. 233 */ 234 int snd_pcm_format_unsigned(snd_pcm_format_t format) 235 { 236 int val; 237 238 val = snd_pcm_format_signed(format); 239 if (val < 0) 240 return val; 241 return !val; 242 } 243 244 EXPORT_SYMBOL(snd_pcm_format_unsigned); 245 246 /** 247 * snd_pcm_format_linear - Check the PCM format is linear 248 * @format: the format to check 249 * 250 * Returns 1 if the given PCM format is linear, 0 if not. 251 */ 252 int snd_pcm_format_linear(snd_pcm_format_t format) 253 { 254 return snd_pcm_format_signed(format) >= 0; 255 } 256 257 EXPORT_SYMBOL(snd_pcm_format_linear); 258 259 /** 260 * snd_pcm_format_little_endian - Check the PCM format is little-endian 261 * @format: the format to check 262 * 263 * Returns 1 if the given PCM format is little-endian, 0 if 264 * big-endian, or a negative error code if endian not specified. 265 */ 266 int snd_pcm_format_little_endian(snd_pcm_format_t format) 267 { 268 int val; 269 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 270 return -EINVAL; 271 if ((val = pcm_formats[format].le) < 0) 272 return -EINVAL; 273 return val; 274 } 275 276 EXPORT_SYMBOL(snd_pcm_format_little_endian); 277 278 /** 279 * snd_pcm_format_big_endian - Check the PCM format is big-endian 280 * @format: the format to check 281 * 282 * Returns 1 if the given PCM format is big-endian, 0 if 283 * little-endian, or a negative error code if endian not specified. 284 */ 285 int snd_pcm_format_big_endian(snd_pcm_format_t format) 286 { 287 int val; 288 289 val = snd_pcm_format_little_endian(format); 290 if (val < 0) 291 return val; 292 return !val; 293 } 294 295 EXPORT_SYMBOL(snd_pcm_format_big_endian); 296 297 /** 298 * snd_pcm_format_width - return the bit-width of the format 299 * @format: the format to check 300 * 301 * Returns the bit-width of the format, or a negative error code 302 * if unknown format. 303 */ 304 int snd_pcm_format_width(snd_pcm_format_t format) 305 { 306 int val; 307 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 308 return -EINVAL; 309 if ((val = pcm_formats[format].width) == 0) 310 return -EINVAL; 311 return val; 312 } 313 314 EXPORT_SYMBOL(snd_pcm_format_width); 315 316 /** 317 * snd_pcm_format_physical_width - return the physical bit-width of the format 318 * @format: the format to check 319 * 320 * Returns the physical bit-width of the format, or a negative error code 321 * if unknown format. 322 */ 323 int snd_pcm_format_physical_width(snd_pcm_format_t format) 324 { 325 int val; 326 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 327 return -EINVAL; 328 if ((val = pcm_formats[format].phys) == 0) 329 return -EINVAL; 330 return val; 331 } 332 333 EXPORT_SYMBOL(snd_pcm_format_physical_width); 334 335 /** 336 * snd_pcm_format_size - return the byte size of samples on the given format 337 * @format: the format to check 338 * @samples: sampling rate 339 * 340 * Returns the byte size of the given samples for the format, or a 341 * negative error code if unknown format. 342 */ 343 ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples) 344 { 345 int phys_width = snd_pcm_format_physical_width(format); 346 if (phys_width < 0) 347 return -EINVAL; 348 return samples * phys_width / 8; 349 } 350 351 EXPORT_SYMBOL(snd_pcm_format_size); 352 353 /** 354 * snd_pcm_format_silence_64 - return the silent data in 8 bytes array 355 * @format: the format to check 356 * 357 * Returns the format pattern to fill or NULL if error. 358 */ 359 const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format) 360 { 361 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 362 return NULL; 363 if (! pcm_formats[format].phys) 364 return NULL; 365 return pcm_formats[format].silence; 366 } 367 368 EXPORT_SYMBOL(snd_pcm_format_silence_64); 369 370 /** 371 * snd_pcm_format_set_silence - set the silence data on the buffer 372 * @format: the PCM format 373 * @data: the buffer pointer 374 * @samples: the number of samples to set silence 375 * 376 * Sets the silence data on the buffer for the given samples. 377 * 378 * Returns zero if successful, or a negative error code on failure. 379 */ 380 int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples) 381 { 382 int width; 383 unsigned char *dst, *pat; 384 385 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST) 386 return -EINVAL; 387 if (samples == 0) 388 return 0; 389 width = pcm_formats[format].phys; /* physical width */ 390 pat = pcm_formats[format].silence; 391 if (! width) 392 return -EINVAL; 393 /* signed or 1 byte data */ 394 if (pcm_formats[format].signd == 1 || width <= 8) { 395 unsigned int bytes = samples * width / 8; 396 memset(data, *pat, bytes); 397 return 0; 398 } 399 /* non-zero samples, fill using a loop */ 400 width /= 8; 401 dst = data; 402 #if 0 403 while (samples--) { 404 memcpy(dst, pat, width); 405 dst += width; 406 } 407 #else 408 /* a bit optimization for constant width */ 409 switch (width) { 410 case 2: 411 while (samples--) { 412 memcpy(dst, pat, 2); 413 dst += 2; 414 } 415 break; 416 case 3: 417 while (samples--) { 418 memcpy(dst, pat, 3); 419 dst += 3; 420 } 421 break; 422 case 4: 423 while (samples--) { 424 memcpy(dst, pat, 4); 425 dst += 4; 426 } 427 break; 428 case 8: 429 while (samples--) { 430 memcpy(dst, pat, 8); 431 dst += 8; 432 } 433 break; 434 } 435 #endif 436 return 0; 437 } 438 439 EXPORT_SYMBOL(snd_pcm_format_set_silence); 440 441 /** 442 * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields 443 * @runtime: the runtime instance 444 * 445 * Determines the rate_min and rate_max fields from the rates bits of 446 * the given runtime->hw. 447 * 448 * Returns zero if successful. 449 */ 450 int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime) 451 { 452 int i; 453 for (i = 0; i < (int)snd_pcm_known_rates.count; i++) { 454 if (runtime->hw.rates & (1 << i)) { 455 runtime->hw.rate_min = snd_pcm_known_rates.list[i]; 456 break; 457 } 458 } 459 for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) { 460 if (runtime->hw.rates & (1 << i)) { 461 runtime->hw.rate_max = snd_pcm_known_rates.list[i]; 462 break; 463 } 464 } 465 return 0; 466 } 467 468 EXPORT_SYMBOL(snd_pcm_limit_hw_rates); 469 470 /** 471 * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit 472 * @rate: the sample rate to convert 473 * 474 * Returns the SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or 475 * SNDRV_PCM_RATE_KNOT for an unknown rate. 476 */ 477 unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate) 478 { 479 unsigned int i; 480 481 for (i = 0; i < snd_pcm_known_rates.count; i++) 482 if (snd_pcm_known_rates.list[i] == rate) 483 return 1u << i; 484 return SNDRV_PCM_RATE_KNOT; 485 } 486 EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit); 487