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 | |
27 | #include "pcm_local.h" |
28 | |
29 | #define SND_PCM_FORMAT_UNKNOWN (-1) |
30 | |
31 | /* NOTE: "signed" prefix must be given below since the default char is |
32 | * unsigned on some architectures! |
33 | */ |
34 | struct pcm_format_data { |
35 | unsigned char width; /* bit width */ |
36 | unsigned char phys; /* physical bit width */ |
37 | signed char le; /* 0 = big-endian, 1 = little-endian, -1 = others */ |
38 | signed char signd; /* 0 = unsigned, 1 = signed, -1 = others */ |
39 | unsigned char silence[8]; /* silence data to fill */ |
40 | }; |
41 | |
42 | /* we do lots of calculations on snd_pcm_format_t; shut up sparse */ |
43 | #define INT __force int |
44 | |
45 | static bool valid_format(snd_pcm_format_t format) |
46 | { |
47 | return (INT)format >= 0 && (INT)format <= (INT)SNDRV_PCM_FORMAT_LAST; |
48 | } |
49 | |
50 | static const struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = { |
51 | [SNDRV_PCM_FORMAT_S8] = { |
52 | .width = 8, .phys = 8, .le = -1, .signd = 1, |
53 | .silence = {}, |
54 | }, |
55 | [SNDRV_PCM_FORMAT_U8] = { |
56 | .width = 8, .phys = 8, .le = -1, .signd = 0, |
57 | .silence = { 0x80 }, |
58 | }, |
59 | [SNDRV_PCM_FORMAT_S16_LE] = { |
60 | .width = 16, .phys = 16, .le = 1, .signd = 1, |
61 | .silence = {}, |
62 | }, |
63 | [SNDRV_PCM_FORMAT_S16_BE] = { |
64 | .width = 16, .phys = 16, .le = 0, .signd = 1, |
65 | .silence = {}, |
66 | }, |
67 | [SNDRV_PCM_FORMAT_U16_LE] = { |
68 | .width = 16, .phys = 16, .le = 1, .signd = 0, |
69 | .silence = { 0x00, 0x80 }, |
70 | }, |
71 | [SNDRV_PCM_FORMAT_U16_BE] = { |
72 | .width = 16, .phys = 16, .le = 0, .signd = 0, |
73 | .silence = { 0x80, 0x00 }, |
74 | }, |
75 | [SNDRV_PCM_FORMAT_S24_LE] = { |
76 | .width = 24, .phys = 32, .le = 1, .signd = 1, |
77 | .silence = {}, |
78 | }, |
79 | [SNDRV_PCM_FORMAT_S24_BE] = { |
80 | .width = 24, .phys = 32, .le = 0, .signd = 1, |
81 | .silence = {}, |
82 | }, |
83 | [SNDRV_PCM_FORMAT_U24_LE] = { |
84 | .width = 24, .phys = 32, .le = 1, .signd = 0, |
85 | .silence = { 0x00, 0x00, 0x80 }, |
86 | }, |
87 | [SNDRV_PCM_FORMAT_U24_BE] = { |
88 | .width = 24, .phys = 32, .le = 0, .signd = 0, |
89 | .silence = { 0x00, 0x80, 0x00, 0x00 }, |
90 | }, |
91 | [SNDRV_PCM_FORMAT_S32_LE] = { |
92 | .width = 32, .phys = 32, .le = 1, .signd = 1, |
93 | .silence = {}, |
94 | }, |
95 | [SNDRV_PCM_FORMAT_S32_BE] = { |
96 | .width = 32, .phys = 32, .le = 0, .signd = 1, |
97 | .silence = {}, |
98 | }, |
99 | [SNDRV_PCM_FORMAT_U32_LE] = { |
100 | .width = 32, .phys = 32, .le = 1, .signd = 0, |
101 | .silence = { 0x00, 0x00, 0x00, 0x80 }, |
102 | }, |
103 | [SNDRV_PCM_FORMAT_U32_BE] = { |
104 | .width = 32, .phys = 32, .le = 0, .signd = 0, |
105 | .silence = { 0x80, 0x00, 0x00, 0x00 }, |
106 | }, |
107 | [SNDRV_PCM_FORMAT_FLOAT_LE] = { |
108 | .width = 32, .phys = 32, .le = 1, .signd = -1, |
109 | .silence = {}, |
110 | }, |
111 | [SNDRV_PCM_FORMAT_FLOAT_BE] = { |
112 | .width = 32, .phys = 32, .le = 0, .signd = -1, |
113 | .silence = {}, |
114 | }, |
115 | [SNDRV_PCM_FORMAT_FLOAT64_LE] = { |
116 | .width = 64, .phys = 64, .le = 1, .signd = -1, |
117 | .silence = {}, |
118 | }, |
119 | [SNDRV_PCM_FORMAT_FLOAT64_BE] = { |
120 | .width = 64, .phys = 64, .le = 0, .signd = -1, |
121 | .silence = {}, |
122 | }, |
123 | [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = { |
124 | .width = 32, .phys = 32, .le = 1, .signd = -1, |
125 | .silence = {}, |
126 | }, |
127 | [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = { |
128 | .width = 32, .phys = 32, .le = 0, .signd = -1, |
129 | .silence = {}, |
130 | }, |
131 | [SNDRV_PCM_FORMAT_MU_LAW] = { |
132 | .width = 8, .phys = 8, .le = -1, .signd = -1, |
133 | .silence = { 0x7f }, |
134 | }, |
135 | [SNDRV_PCM_FORMAT_A_LAW] = { |
136 | .width = 8, .phys = 8, .le = -1, .signd = -1, |
137 | .silence = { 0x55 }, |
138 | }, |
139 | [SNDRV_PCM_FORMAT_IMA_ADPCM] = { |
140 | .width = 4, .phys = 4, .le = -1, .signd = -1, |
141 | .silence = {}, |
142 | }, |
143 | [SNDRV_PCM_FORMAT_G723_24] = { |
144 | .width = 3, .phys = 3, .le = -1, .signd = -1, |
145 | .silence = {}, |
146 | }, |
147 | [SNDRV_PCM_FORMAT_G723_40] = { |
148 | .width = 5, .phys = 5, .le = -1, .signd = -1, |
149 | .silence = {}, |
150 | }, |
151 | [SNDRV_PCM_FORMAT_DSD_U8] = { |
152 | .width = 8, .phys = 8, .le = 1, .signd = 0, |
153 | .silence = { 0x69 }, |
154 | }, |
155 | [SNDRV_PCM_FORMAT_DSD_U16_LE] = { |
156 | .width = 16, .phys = 16, .le = 1, .signd = 0, |
157 | .silence = { 0x69, 0x69 }, |
158 | }, |
159 | [SNDRV_PCM_FORMAT_DSD_U32_LE] = { |
160 | .width = 32, .phys = 32, .le = 1, .signd = 0, |
161 | .silence = { 0x69, 0x69, 0x69, 0x69 }, |
162 | }, |
163 | [SNDRV_PCM_FORMAT_DSD_U16_BE] = { |
164 | .width = 16, .phys = 16, .le = 0, .signd = 0, |
165 | .silence = { 0x69, 0x69 }, |
166 | }, |
167 | [SNDRV_PCM_FORMAT_DSD_U32_BE] = { |
168 | .width = 32, .phys = 32, .le = 0, .signd = 0, |
169 | .silence = { 0x69, 0x69, 0x69, 0x69 }, |
170 | }, |
171 | /* FIXME: the following two formats are not defined properly yet */ |
172 | [SNDRV_PCM_FORMAT_MPEG] = { |
173 | .le = -1, .signd = -1, |
174 | }, |
175 | [SNDRV_PCM_FORMAT_GSM] = { |
176 | .le = -1, .signd = -1, |
177 | }, |
178 | [SNDRV_PCM_FORMAT_S20_LE] = { |
179 | .width = 20, .phys = 32, .le = 1, .signd = 1, |
180 | .silence = {}, |
181 | }, |
182 | [SNDRV_PCM_FORMAT_S20_BE] = { |
183 | .width = 20, .phys = 32, .le = 0, .signd = 1, |
184 | .silence = {}, |
185 | }, |
186 | [SNDRV_PCM_FORMAT_U20_LE] = { |
187 | .width = 20, .phys = 32, .le = 1, .signd = 0, |
188 | .silence = { 0x00, 0x00, 0x08, 0x00 }, |
189 | }, |
190 | [SNDRV_PCM_FORMAT_U20_BE] = { |
191 | .width = 20, .phys = 32, .le = 0, .signd = 0, |
192 | .silence = { 0x00, 0x08, 0x00, 0x00 }, |
193 | }, |
194 | /* FIXME: the following format is not defined properly yet */ |
195 | [SNDRV_PCM_FORMAT_SPECIAL] = { |
196 | .le = -1, .signd = -1, |
197 | }, |
198 | [SNDRV_PCM_FORMAT_S24_3LE] = { |
199 | .width = 24, .phys = 24, .le = 1, .signd = 1, |
200 | .silence = {}, |
201 | }, |
202 | [SNDRV_PCM_FORMAT_S24_3BE] = { |
203 | .width = 24, .phys = 24, .le = 0, .signd = 1, |
204 | .silence = {}, |
205 | }, |
206 | [SNDRV_PCM_FORMAT_U24_3LE] = { |
207 | .width = 24, .phys = 24, .le = 1, .signd = 0, |
208 | .silence = { 0x00, 0x00, 0x80 }, |
209 | }, |
210 | [SNDRV_PCM_FORMAT_U24_3BE] = { |
211 | .width = 24, .phys = 24, .le = 0, .signd = 0, |
212 | .silence = { 0x80, 0x00, 0x00 }, |
213 | }, |
214 | [SNDRV_PCM_FORMAT_S20_3LE] = { |
215 | .width = 20, .phys = 24, .le = 1, .signd = 1, |
216 | .silence = {}, |
217 | }, |
218 | [SNDRV_PCM_FORMAT_S20_3BE] = { |
219 | .width = 20, .phys = 24, .le = 0, .signd = 1, |
220 | .silence = {}, |
221 | }, |
222 | [SNDRV_PCM_FORMAT_U20_3LE] = { |
223 | .width = 20, .phys = 24, .le = 1, .signd = 0, |
224 | .silence = { 0x00, 0x00, 0x08 }, |
225 | }, |
226 | [SNDRV_PCM_FORMAT_U20_3BE] = { |
227 | .width = 20, .phys = 24, .le = 0, .signd = 0, |
228 | .silence = { 0x08, 0x00, 0x00 }, |
229 | }, |
230 | [SNDRV_PCM_FORMAT_S18_3LE] = { |
231 | .width = 18, .phys = 24, .le = 1, .signd = 1, |
232 | .silence = {}, |
233 | }, |
234 | [SNDRV_PCM_FORMAT_S18_3BE] = { |
235 | .width = 18, .phys = 24, .le = 0, .signd = 1, |
236 | .silence = {}, |
237 | }, |
238 | [SNDRV_PCM_FORMAT_U18_3LE] = { |
239 | .width = 18, .phys = 24, .le = 1, .signd = 0, |
240 | .silence = { 0x00, 0x00, 0x02 }, |
241 | }, |
242 | [SNDRV_PCM_FORMAT_U18_3BE] = { |
243 | .width = 18, .phys = 24, .le = 0, .signd = 0, |
244 | .silence = { 0x02, 0x00, 0x00 }, |
245 | }, |
246 | [SNDRV_PCM_FORMAT_G723_24_1B] = { |
247 | .width = 3, .phys = 8, .le = -1, .signd = -1, |
248 | .silence = {}, |
249 | }, |
250 | [SNDRV_PCM_FORMAT_G723_40_1B] = { |
251 | .width = 5, .phys = 8, .le = -1, .signd = -1, |
252 | .silence = {}, |
253 | }, |
254 | }; |
255 | |
256 | |
257 | /** |
258 | * snd_pcm_format_signed - Check the PCM format is signed linear |
259 | * @format: the format to check |
260 | * |
261 | * Return: 1 if the given PCM format is signed linear, 0 if unsigned |
262 | * linear, and a negative error code for non-linear formats. |
263 | */ |
264 | int snd_pcm_format_signed(snd_pcm_format_t format) |
265 | { |
266 | int val; |
267 | if (!valid_format(format)) |
268 | return -EINVAL; |
269 | val = pcm_formats[(INT)format].signd; |
270 | if (val < 0) |
271 | return -EINVAL; |
272 | return val; |
273 | } |
274 | EXPORT_SYMBOL(snd_pcm_format_signed); |
275 | |
276 | /** |
277 | * snd_pcm_format_unsigned - Check the PCM format is unsigned linear |
278 | * @format: the format to check |
279 | * |
280 | * Return: 1 if the given PCM format is unsigned linear, 0 if signed |
281 | * linear, and a negative error code for non-linear formats. |
282 | */ |
283 | int snd_pcm_format_unsigned(snd_pcm_format_t format) |
284 | { |
285 | int val; |
286 | |
287 | val = snd_pcm_format_signed(format); |
288 | if (val < 0) |
289 | return val; |
290 | return !val; |
291 | } |
292 | EXPORT_SYMBOL(snd_pcm_format_unsigned); |
293 | |
294 | /** |
295 | * snd_pcm_format_linear - Check the PCM format is linear |
296 | * @format: the format to check |
297 | * |
298 | * Return: 1 if the given PCM format is linear, 0 if not. |
299 | */ |
300 | int snd_pcm_format_linear(snd_pcm_format_t format) |
301 | { |
302 | return snd_pcm_format_signed(format) >= 0; |
303 | } |
304 | EXPORT_SYMBOL(snd_pcm_format_linear); |
305 | |
306 | /** |
307 | * snd_pcm_format_little_endian - Check the PCM format is little-endian |
308 | * @format: the format to check |
309 | * |
310 | * Return: 1 if the given PCM format is little-endian, 0 if |
311 | * big-endian, or a negative error code if endian not specified. |
312 | */ |
313 | int snd_pcm_format_little_endian(snd_pcm_format_t format) |
314 | { |
315 | int val; |
316 | if (!valid_format(format)) |
317 | return -EINVAL; |
318 | val = pcm_formats[(INT)format].le; |
319 | if (val < 0) |
320 | return -EINVAL; |
321 | return val; |
322 | } |
323 | EXPORT_SYMBOL(snd_pcm_format_little_endian); |
324 | |
325 | /** |
326 | * snd_pcm_format_big_endian - Check the PCM format is big-endian |
327 | * @format: the format to check |
328 | * |
329 | * Return: 1 if the given PCM format is big-endian, 0 if |
330 | * little-endian, or a negative error code if endian not specified. |
331 | */ |
332 | int snd_pcm_format_big_endian(snd_pcm_format_t format) |
333 | { |
334 | int val; |
335 | |
336 | val = snd_pcm_format_little_endian(format); |
337 | if (val < 0) |
338 | return val; |
339 | return !val; |
340 | } |
341 | EXPORT_SYMBOL(snd_pcm_format_big_endian); |
342 | |
343 | /** |
344 | * snd_pcm_format_width - return the bit-width of the format |
345 | * @format: the format to check |
346 | * |
347 | * Return: The bit-width of the format, or a negative error code |
348 | * if unknown format. |
349 | */ |
350 | int snd_pcm_format_width(snd_pcm_format_t format) |
351 | { |
352 | int val; |
353 | if (!valid_format(format)) |
354 | return -EINVAL; |
355 | val = pcm_formats[(INT)format].width; |
356 | if (!val) |
357 | return -EINVAL; |
358 | return val; |
359 | } |
360 | EXPORT_SYMBOL(snd_pcm_format_width); |
361 | |
362 | /** |
363 | * snd_pcm_format_physical_width - return the physical bit-width of the format |
364 | * @format: the format to check |
365 | * |
366 | * Return: The physical bit-width of the format, or a negative error code |
367 | * if unknown format. |
368 | */ |
369 | int snd_pcm_format_physical_width(snd_pcm_format_t format) |
370 | { |
371 | int val; |
372 | if (!valid_format(format)) |
373 | return -EINVAL; |
374 | val = pcm_formats[(INT)format].phys; |
375 | if (!val) |
376 | return -EINVAL; |
377 | return val; |
378 | } |
379 | EXPORT_SYMBOL(snd_pcm_format_physical_width); |
380 | |
381 | /** |
382 | * snd_pcm_format_size - return the byte size of samples on the given format |
383 | * @format: the format to check |
384 | * @samples: sampling rate |
385 | * |
386 | * Return: The byte size of the given samples for the format, or a |
387 | * negative error code if unknown format. |
388 | */ |
389 | ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples) |
390 | { |
391 | int phys_width = snd_pcm_format_physical_width(format); |
392 | if (phys_width < 0) |
393 | return -EINVAL; |
394 | return samples * phys_width / 8; |
395 | } |
396 | EXPORT_SYMBOL(snd_pcm_format_size); |
397 | |
398 | /** |
399 | * snd_pcm_format_silence_64 - return the silent data in 8 bytes array |
400 | * @format: the format to check |
401 | * |
402 | * Return: The format pattern to fill or %NULL if error. |
403 | */ |
404 | const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format) |
405 | { |
406 | if (!valid_format(format)) |
407 | return NULL; |
408 | if (! pcm_formats[(INT)format].phys) |
409 | return NULL; |
410 | return pcm_formats[(INT)format].silence; |
411 | } |
412 | EXPORT_SYMBOL(snd_pcm_format_silence_64); |
413 | |
414 | /** |
415 | * snd_pcm_format_set_silence - set the silence data on the buffer |
416 | * @format: the PCM format |
417 | * @data: the buffer pointer |
418 | * @samples: the number of samples to set silence |
419 | * |
420 | * Sets the silence data on the buffer for the given samples. |
421 | * |
422 | * Return: Zero if successful, or a negative error code on failure. |
423 | */ |
424 | int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples) |
425 | { |
426 | int width; |
427 | unsigned char *dst; |
428 | const unsigned char *pat; |
429 | |
430 | if (!valid_format(format)) |
431 | return -EINVAL; |
432 | if (samples == 0) |
433 | return 0; |
434 | width = pcm_formats[(INT)format].phys; /* physical width */ |
435 | pat = pcm_formats[(INT)format].silence; |
436 | if (!width || !pat) |
437 | return -EINVAL; |
438 | /* signed or 1 byte data */ |
439 | if (pcm_formats[(INT)format].signd == 1 || width <= 8) { |
440 | unsigned int bytes = samples * width / 8; |
441 | memset(data, *pat, bytes); |
442 | return 0; |
443 | } |
444 | /* non-zero samples, fill using a loop */ |
445 | width /= 8; |
446 | dst = data; |
447 | #if 0 |
448 | while (samples--) { |
449 | memcpy(dst, pat, width); |
450 | dst += width; |
451 | } |
452 | #else |
453 | /* a bit optimization for constant width */ |
454 | switch (width) { |
455 | case 2: |
456 | while (samples--) { |
457 | memcpy(dst, pat, 2); |
458 | dst += 2; |
459 | } |
460 | break; |
461 | case 3: |
462 | while (samples--) { |
463 | memcpy(dst, pat, 3); |
464 | dst += 3; |
465 | } |
466 | break; |
467 | case 4: |
468 | while (samples--) { |
469 | memcpy(dst, pat, 4); |
470 | dst += 4; |
471 | } |
472 | break; |
473 | case 8: |
474 | while (samples--) { |
475 | memcpy(dst, pat, 8); |
476 | dst += 8; |
477 | } |
478 | break; |
479 | } |
480 | #endif |
481 | return 0; |
482 | } |
483 | EXPORT_SYMBOL(snd_pcm_format_set_silence); |
484 | |
485 | /** |
486 | * snd_pcm_hw_limit_rates - determine rate_min/rate_max fields |
487 | * @hw: the pcm hw instance |
488 | * |
489 | * Determines the rate_min and rate_max fields from the rates bits of |
490 | * the given hw. |
491 | * |
492 | * Return: Zero if successful. |
493 | */ |
494 | int snd_pcm_hw_limit_rates(struct snd_pcm_hardware *hw) |
495 | { |
496 | int i; |
497 | for (i = 0; i < (int)snd_pcm_known_rates.count; i++) { |
498 | if (hw->rates & (1 << i)) { |
499 | hw->rate_min = snd_pcm_known_rates.list[i]; |
500 | break; |
501 | } |
502 | } |
503 | for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) { |
504 | if (hw->rates & (1 << i)) { |
505 | hw->rate_max = snd_pcm_known_rates.list[i]; |
506 | break; |
507 | } |
508 | } |
509 | return 0; |
510 | } |
511 | EXPORT_SYMBOL(snd_pcm_hw_limit_rates); |
512 | |
513 | /** |
514 | * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit |
515 | * @rate: the sample rate to convert |
516 | * |
517 | * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or |
518 | * SNDRV_PCM_RATE_KNOT for an unknown rate. |
519 | */ |
520 | unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate) |
521 | { |
522 | unsigned int i; |
523 | |
524 | for (i = 0; i < snd_pcm_known_rates.count; i++) |
525 | if (snd_pcm_known_rates.list[i] == rate) |
526 | return 1u << i; |
527 | return SNDRV_PCM_RATE_KNOT; |
528 | } |
529 | EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit); |
530 | |
531 | /** |
532 | * snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate |
533 | * @rate_bit: the rate bit to convert |
534 | * |
535 | * Return: The sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag |
536 | * or 0 for an unknown rate bit. |
537 | */ |
538 | unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit) |
539 | { |
540 | unsigned int i; |
541 | |
542 | for (i = 0; i < snd_pcm_known_rates.count; i++) |
543 | if ((1u << i) == rate_bit) |
544 | return snd_pcm_known_rates.list[i]; |
545 | return 0; |
546 | } |
547 | EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate); |
548 | |
549 | static unsigned int snd_pcm_rate_mask_sanitize(unsigned int rates) |
550 | { |
551 | if (rates & SNDRV_PCM_RATE_CONTINUOUS) |
552 | return SNDRV_PCM_RATE_CONTINUOUS; |
553 | else if (rates & SNDRV_PCM_RATE_KNOT) |
554 | return SNDRV_PCM_RATE_KNOT; |
555 | return rates; |
556 | } |
557 | |
558 | /** |
559 | * snd_pcm_rate_mask_intersect - computes the intersection between two rate masks |
560 | * @rates_a: The first rate mask |
561 | * @rates_b: The second rate mask |
562 | * |
563 | * This function computes the rates that are supported by both rate masks passed |
564 | * to the function. It will take care of the special handling of |
565 | * SNDRV_PCM_RATE_CONTINUOUS and SNDRV_PCM_RATE_KNOT. |
566 | * |
567 | * Return: A rate mask containing the rates that are supported by both rates_a |
568 | * and rates_b. |
569 | */ |
570 | unsigned int snd_pcm_rate_mask_intersect(unsigned int rates_a, |
571 | unsigned int rates_b) |
572 | { |
573 | rates_a = snd_pcm_rate_mask_sanitize(rates: rates_a); |
574 | rates_b = snd_pcm_rate_mask_sanitize(rates: rates_b); |
575 | |
576 | if (rates_a & SNDRV_PCM_RATE_CONTINUOUS) |
577 | return rates_b; |
578 | else if (rates_b & SNDRV_PCM_RATE_CONTINUOUS) |
579 | return rates_a; |
580 | else if (rates_a & SNDRV_PCM_RATE_KNOT) |
581 | return rates_b; |
582 | else if (rates_b & SNDRV_PCM_RATE_KNOT) |
583 | return rates_a; |
584 | return rates_a & rates_b; |
585 | } |
586 | EXPORT_SYMBOL_GPL(snd_pcm_rate_mask_intersect); |
587 | |
588 | /** |
589 | * snd_pcm_rate_range_to_bits - converts rate range to SNDRV_PCM_RATE_xxx bit |
590 | * @rate_min: the minimum sample rate |
591 | * @rate_max: the maximum sample rate |
592 | * |
593 | * This function has an implicit assumption: the rates in the given range have |
594 | * only the pre-defined rates like 44100 or 16000. |
595 | * |
596 | * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate range, |
597 | * or SNDRV_PCM_RATE_KNOT for an unknown range. |
598 | */ |
599 | unsigned int snd_pcm_rate_range_to_bits(unsigned int rate_min, |
600 | unsigned int rate_max) |
601 | { |
602 | unsigned int rates = 0; |
603 | int i; |
604 | |
605 | for (i = 0; i < snd_pcm_known_rates.count; i++) { |
606 | if (snd_pcm_known_rates.list[i] >= rate_min |
607 | && snd_pcm_known_rates.list[i] <= rate_max) |
608 | rates |= 1 << i; |
609 | } |
610 | |
611 | if (!rates) |
612 | rates = SNDRV_PCM_RATE_KNOT; |
613 | |
614 | return rates; |
615 | } |
616 | EXPORT_SYMBOL_GPL(snd_pcm_rate_range_to_bits); |
617 | |