Root/sound/core/pcm_misc.c

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 */
30struct 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/* we do lots of calculations on snd_pcm_format_t; shut up sparse */
39#define INT __force int
40
41static struct pcm_format_data pcm_formats[(INT)SNDRV_PCM_FORMAT_LAST+1] = {
42    [SNDRV_PCM_FORMAT_S8] = {
43        .width = 8, .phys = 8, .le = -1, .signd = 1,
44        .silence = {},
45    },
46    [SNDRV_PCM_FORMAT_U8] = {
47        .width = 8, .phys = 8, .le = -1, .signd = 0,
48        .silence = { 0x80 },
49    },
50    [SNDRV_PCM_FORMAT_S16_LE] = {
51        .width = 16, .phys = 16, .le = 1, .signd = 1,
52        .silence = {},
53    },
54    [SNDRV_PCM_FORMAT_S16_BE] = {
55        .width = 16, .phys = 16, .le = 0, .signd = 1,
56        .silence = {},
57    },
58    [SNDRV_PCM_FORMAT_U16_LE] = {
59        .width = 16, .phys = 16, .le = 1, .signd = 0,
60        .silence = { 0x00, 0x80 },
61    },
62    [SNDRV_PCM_FORMAT_U16_BE] = {
63        .width = 16, .phys = 16, .le = 0, .signd = 0,
64        .silence = { 0x80, 0x00 },
65    },
66    [SNDRV_PCM_FORMAT_S24_LE] = {
67        .width = 24, .phys = 32, .le = 1, .signd = 1,
68        .silence = {},
69    },
70    [SNDRV_PCM_FORMAT_S24_BE] = {
71        .width = 24, .phys = 32, .le = 0, .signd = 1,
72        .silence = {},
73    },
74    [SNDRV_PCM_FORMAT_U24_LE] = {
75        .width = 24, .phys = 32, .le = 1, .signd = 0,
76        .silence = { 0x00, 0x00, 0x80 },
77    },
78    [SNDRV_PCM_FORMAT_U24_BE] = {
79        .width = 24, .phys = 32, .le = 0, .signd = 0,
80        .silence = { 0x00, 0x80, 0x00, 0x00 },
81    },
82    [SNDRV_PCM_FORMAT_S32_LE] = {
83        .width = 32, .phys = 32, .le = 1, .signd = 1,
84        .silence = {},
85    },
86    [SNDRV_PCM_FORMAT_S32_BE] = {
87        .width = 32, .phys = 32, .le = 0, .signd = 1,
88        .silence = {},
89    },
90    [SNDRV_PCM_FORMAT_U32_LE] = {
91        .width = 32, .phys = 32, .le = 1, .signd = 0,
92        .silence = { 0x00, 0x00, 0x00, 0x80 },
93    },
94    [SNDRV_PCM_FORMAT_U32_BE] = {
95        .width = 32, .phys = 32, .le = 0, .signd = 0,
96        .silence = { 0x80, 0x00, 0x00, 0x00 },
97    },
98    [SNDRV_PCM_FORMAT_FLOAT_LE] = {
99        .width = 32, .phys = 32, .le = 1, .signd = -1,
100        .silence = {},
101    },
102    [SNDRV_PCM_FORMAT_FLOAT_BE] = {
103        .width = 32, .phys = 32, .le = 0, .signd = -1,
104        .silence = {},
105    },
106    [SNDRV_PCM_FORMAT_FLOAT64_LE] = {
107        .width = 64, .phys = 64, .le = 1, .signd = -1,
108        .silence = {},
109    },
110    [SNDRV_PCM_FORMAT_FLOAT64_BE] = {
111        .width = 64, .phys = 64, .le = 0, .signd = -1,
112        .silence = {},
113    },
114    [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
115        .width = 32, .phys = 32, .le = 1, .signd = -1,
116        .silence = {},
117    },
118    [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
119        .width = 32, .phys = 32, .le = 0, .signd = -1,
120        .silence = {},
121    },
122    [SNDRV_PCM_FORMAT_MU_LAW] = {
123        .width = 8, .phys = 8, .le = -1, .signd = -1,
124        .silence = { 0x7f },
125    },
126    [SNDRV_PCM_FORMAT_A_LAW] = {
127        .width = 8, .phys = 8, .le = -1, .signd = -1,
128        .silence = { 0x55 },
129    },
130    [SNDRV_PCM_FORMAT_IMA_ADPCM] = {
131        .width = 4, .phys = 4, .le = -1, .signd = -1,
132        .silence = {},
133    },
134    [SNDRV_PCM_FORMAT_G723_24] = {
135        .width = 3, .phys = 3, .le = -1, .signd = -1,
136        .silence = {},
137    },
138    [SNDRV_PCM_FORMAT_G723_40] = {
139        .width = 5, .phys = 5, .le = -1, .signd = -1,
140        .silence = {},
141    },
142    /* FIXME: the following three formats are not defined properly yet */
143    [SNDRV_PCM_FORMAT_MPEG] = {
144        .le = -1, .signd = -1,
145    },
146    [SNDRV_PCM_FORMAT_GSM] = {
147        .le = -1, .signd = -1,
148    },
149    [SNDRV_PCM_FORMAT_SPECIAL] = {
150        .le = -1, .signd = -1,
151    },
152    [SNDRV_PCM_FORMAT_S24_3LE] = {
153        .width = 24, .phys = 24, .le = 1, .signd = 1,
154        .silence = {},
155    },
156    [SNDRV_PCM_FORMAT_S24_3BE] = {
157        .width = 24, .phys = 24, .le = 0, .signd = 1,
158        .silence = {},
159    },
160    [SNDRV_PCM_FORMAT_U24_3LE] = {
161        .width = 24, .phys = 24, .le = 1, .signd = 0,
162        .silence = { 0x00, 0x00, 0x80 },
163    },
164    [SNDRV_PCM_FORMAT_U24_3BE] = {
165        .width = 24, .phys = 24, .le = 0, .signd = 0,
166        .silence = { 0x80, 0x00, 0x00 },
167    },
168    [SNDRV_PCM_FORMAT_S20_3LE] = {
169        .width = 20, .phys = 24, .le = 1, .signd = 1,
170        .silence = {},
171    },
172    [SNDRV_PCM_FORMAT_S20_3BE] = {
173        .width = 20, .phys = 24, .le = 0, .signd = 1,
174        .silence = {},
175    },
176    [SNDRV_PCM_FORMAT_U20_3LE] = {
177        .width = 20, .phys = 24, .le = 1, .signd = 0,
178        .silence = { 0x00, 0x00, 0x08 },
179    },
180    [SNDRV_PCM_FORMAT_U20_3BE] = {
181        .width = 20, .phys = 24, .le = 0, .signd = 0,
182        .silence = { 0x08, 0x00, 0x00 },
183    },
184    [SNDRV_PCM_FORMAT_S18_3LE] = {
185        .width = 18, .phys = 24, .le = 1, .signd = 1,
186        .silence = {},
187    },
188    [SNDRV_PCM_FORMAT_S18_3BE] = {
189        .width = 18, .phys = 24, .le = 0, .signd = 1,
190        .silence = {},
191    },
192    [SNDRV_PCM_FORMAT_U18_3LE] = {
193        .width = 18, .phys = 24, .le = 1, .signd = 0,
194        .silence = { 0x00, 0x00, 0x02 },
195    },
196    [SNDRV_PCM_FORMAT_U18_3BE] = {
197        .width = 18, .phys = 24, .le = 0, .signd = 0,
198        .silence = { 0x02, 0x00, 0x00 },
199    },
200    [SNDRV_PCM_FORMAT_G723_24_1B] = {
201        .width = 3, .phys = 8, .le = -1, .signd = -1,
202        .silence = {},
203    },
204    [SNDRV_PCM_FORMAT_G723_40_1B] = {
205        .width = 5, .phys = 8, .le = -1, .signd = -1,
206        .silence = {},
207    },
208};
209
210
211/**
212 * snd_pcm_format_signed - Check the PCM format is signed linear
213 * @format: the format to check
214 *
215 * Returns 1 if the given PCM format is signed linear, 0 if unsigned
216 * linear, and a negative error code for non-linear formats.
217 */
218int snd_pcm_format_signed(snd_pcm_format_t format)
219{
220    int val;
221    if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
222        return -EINVAL;
223    if ((val = pcm_formats[(INT)format].signd) < 0)
224        return -EINVAL;
225    return val;
226}
227
228EXPORT_SYMBOL(snd_pcm_format_signed);
229
230/**
231 * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
232 * @format: the format to check
233 *
234 * Returns 1 if the given PCM format is unsigned linear, 0 if signed
235 * linear, and a negative error code for non-linear formats.
236 */
237int snd_pcm_format_unsigned(snd_pcm_format_t format)
238{
239    int val;
240
241    val = snd_pcm_format_signed(format);
242    if (val < 0)
243        return val;
244    return !val;
245}
246
247EXPORT_SYMBOL(snd_pcm_format_unsigned);
248
249/**
250 * snd_pcm_format_linear - Check the PCM format is linear
251 * @format: the format to check
252 *
253 * Returns 1 if the given PCM format is linear, 0 if not.
254 */
255int snd_pcm_format_linear(snd_pcm_format_t format)
256{
257    return snd_pcm_format_signed(format) >= 0;
258}
259
260EXPORT_SYMBOL(snd_pcm_format_linear);
261
262/**
263 * snd_pcm_format_little_endian - Check the PCM format is little-endian
264 * @format: the format to check
265 *
266 * Returns 1 if the given PCM format is little-endian, 0 if
267 * big-endian, or a negative error code if endian not specified.
268 */
269int snd_pcm_format_little_endian(snd_pcm_format_t format)
270{
271    int val;
272    if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
273        return -EINVAL;
274    if ((val = pcm_formats[(INT)format].le) < 0)
275        return -EINVAL;
276    return val;
277}
278
279EXPORT_SYMBOL(snd_pcm_format_little_endian);
280
281/**
282 * snd_pcm_format_big_endian - Check the PCM format is big-endian
283 * @format: the format to check
284 *
285 * Returns 1 if the given PCM format is big-endian, 0 if
286 * little-endian, or a negative error code if endian not specified.
287 */
288int snd_pcm_format_big_endian(snd_pcm_format_t format)
289{
290    int val;
291
292    val = snd_pcm_format_little_endian(format);
293    if (val < 0)
294        return val;
295    return !val;
296}
297
298EXPORT_SYMBOL(snd_pcm_format_big_endian);
299
300/**
301 * snd_pcm_format_width - return the bit-width of the format
302 * @format: the format to check
303 *
304 * Returns the bit-width of the format, or a negative error code
305 * if unknown format.
306 */
307int snd_pcm_format_width(snd_pcm_format_t format)
308{
309    int val;
310    if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
311        return -EINVAL;
312    if ((val = pcm_formats[(INT)format].width) == 0)
313        return -EINVAL;
314    return val;
315}
316
317EXPORT_SYMBOL(snd_pcm_format_width);
318
319/**
320 * snd_pcm_format_physical_width - return the physical bit-width of the format
321 * @format: the format to check
322 *
323 * Returns the physical bit-width of the format, or a negative error code
324 * if unknown format.
325 */
326int snd_pcm_format_physical_width(snd_pcm_format_t format)
327{
328    int val;
329    if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
330        return -EINVAL;
331    if ((val = pcm_formats[(INT)format].phys) == 0)
332        return -EINVAL;
333    return val;
334}
335
336EXPORT_SYMBOL(snd_pcm_format_physical_width);
337
338/**
339 * snd_pcm_format_size - return the byte size of samples on the given format
340 * @format: the format to check
341 * @samples: sampling rate
342 *
343 * Returns the byte size of the given samples for the format, or a
344 * negative error code if unknown format.
345 */
346ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
347{
348    int phys_width = snd_pcm_format_physical_width(format);
349    if (phys_width < 0)
350        return -EINVAL;
351    return samples * phys_width / 8;
352}
353
354EXPORT_SYMBOL(snd_pcm_format_size);
355
356/**
357 * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
358 * @format: the format to check
359 *
360 * Returns the format pattern to fill or NULL if error.
361 */
362const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
363{
364    if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
365        return NULL;
366    if (! pcm_formats[(INT)format].phys)
367        return NULL;
368    return pcm_formats[(INT)format].silence;
369}
370
371EXPORT_SYMBOL(snd_pcm_format_silence_64);
372
373/**
374 * snd_pcm_format_set_silence - set the silence data on the buffer
375 * @format: the PCM format
376 * @data: the buffer pointer
377 * @samples: the number of samples to set silence
378 *
379 * Sets the silence data on the buffer for the given samples.
380 *
381 * Returns zero if successful, or a negative error code on failure.
382 */
383int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
384{
385    int width;
386    unsigned char *dst, *pat;
387
388    if ((INT)format < 0 || (INT)format > (INT)SNDRV_PCM_FORMAT_LAST)
389        return -EINVAL;
390    if (samples == 0)
391        return 0;
392    width = pcm_formats[(INT)format].phys; /* physical width */
393    pat = pcm_formats[(INT)format].silence;
394    if (! width)
395        return -EINVAL;
396    /* signed or 1 byte data */
397    if (pcm_formats[(INT)format].signd == 1 || width <= 8) {
398        unsigned int bytes = samples * width / 8;
399        memset(data, *pat, bytes);
400        return 0;
401    }
402    /* non-zero samples, fill using a loop */
403    width /= 8;
404    dst = data;
405#if 0
406    while (samples--) {
407        memcpy(dst, pat, width);
408        dst += width;
409    }
410#else
411    /* a bit optimization for constant width */
412    switch (width) {
413    case 2:
414        while (samples--) {
415            memcpy(dst, pat, 2);
416            dst += 2;
417        }
418        break;
419    case 3:
420        while (samples--) {
421            memcpy(dst, pat, 3);
422            dst += 3;
423        }
424        break;
425    case 4:
426        while (samples--) {
427            memcpy(dst, pat, 4);
428            dst += 4;
429        }
430        break;
431    case 8:
432        while (samples--) {
433            memcpy(dst, pat, 8);
434            dst += 8;
435        }
436        break;
437    }
438#endif
439    return 0;
440}
441
442EXPORT_SYMBOL(snd_pcm_format_set_silence);
443
444/**
445 * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields
446 * @runtime: the runtime instance
447 *
448 * Determines the rate_min and rate_max fields from the rates bits of
449 * the given runtime->hw.
450 *
451 * Returns zero if successful.
452 */
453int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime)
454{
455    int i;
456    for (i = 0; i < (int)snd_pcm_known_rates.count; i++) {
457        if (runtime->hw.rates & (1 << i)) {
458            runtime->hw.rate_min = snd_pcm_known_rates.list[i];
459            break;
460        }
461    }
462    for (i = (int)snd_pcm_known_rates.count - 1; i >= 0; i--) {
463        if (runtime->hw.rates & (1 << i)) {
464            runtime->hw.rate_max = snd_pcm_known_rates.list[i];
465            break;
466        }
467    }
468    return 0;
469}
470
471EXPORT_SYMBOL(snd_pcm_limit_hw_rates);
472
473/**
474 * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
475 * @rate: the sample rate to convert
476 *
477 * Returns the SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
478 * SNDRV_PCM_RATE_KNOT for an unknown rate.
479 */
480unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
481{
482    unsigned int i;
483
484    for (i = 0; i < snd_pcm_known_rates.count; i++)
485        if (snd_pcm_known_rates.list[i] == rate)
486            return 1u << i;
487    return SNDRV_PCM_RATE_KNOT;
488}
489EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);
490

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