2 * PCM Interface - misc routines
3 * Copyright (c) 1998 by Jaroslav Kysela <perex@perex.cz>
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.
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.
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
22 #include <linux/time.h>
23 #include <sound/core.h>
24 #include <sound/pcm.h>
25 #define SND_PCM_FORMAT_UNKNOWN (-1)
27 /* NOTE: "signed" prefix must be given below since the default char is
28 * unsigned on some architectures!
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 */
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,
43 [SNDRV_PCM_FORMAT_U8] = {
44 .width = 8, .phys = 8, .le = -1, .signd = 0,
47 [SNDRV_PCM_FORMAT_S16_LE] = {
48 .width = 16, .phys = 16, .le = 1, .signd = 1,
51 [SNDRV_PCM_FORMAT_S16_BE] = {
52 .width = 16, .phys = 16, .le = 0, .signd = 1,
55 [SNDRV_PCM_FORMAT_U16_LE] = {
56 .width = 16, .phys = 16, .le = 1, .signd = 0,
57 .silence = { 0x00, 0x80 },
59 [SNDRV_PCM_FORMAT_U16_BE] = {
60 .width = 16, .phys = 16, .le = 0, .signd = 0,
61 .silence = { 0x80, 0x00 },
63 [SNDRV_PCM_FORMAT_S24_LE] = {
64 .width = 24, .phys = 32, .le = 1, .signd = 1,
67 [SNDRV_PCM_FORMAT_S24_BE] = {
68 .width = 24, .phys = 32, .le = 0, .signd = 1,
71 [SNDRV_PCM_FORMAT_U24_LE] = {
72 .width = 24, .phys = 32, .le = 1, .signd = 0,
73 .silence = { 0x00, 0x00, 0x80 },
75 [SNDRV_PCM_FORMAT_U24_BE] = {
76 .width = 24, .phys = 32, .le = 0, .signd = 0,
77 .silence = { 0x00, 0x80, 0x00, 0x00 },
79 [SNDRV_PCM_FORMAT_S32_LE] = {
80 .width = 32, .phys = 32, .le = 1, .signd = 1,
83 [SNDRV_PCM_FORMAT_S32_BE] = {
84 .width = 32, .phys = 32, .le = 0, .signd = 1,
87 [SNDRV_PCM_FORMAT_U32_LE] = {
88 .width = 32, .phys = 32, .le = 1, .signd = 0,
89 .silence = { 0x00, 0x00, 0x00, 0x80 },
91 [SNDRV_PCM_FORMAT_U32_BE] = {
92 .width = 32, .phys = 32, .le = 0, .signd = 0,
93 .silence = { 0x80, 0x00, 0x00, 0x00 },
95 [SNDRV_PCM_FORMAT_FLOAT_LE] = {
96 .width = 32, .phys = 32, .le = 1, .signd = -1,
99 [SNDRV_PCM_FORMAT_FLOAT_BE] = {
100 .width = 32, .phys = 32, .le = 0, .signd = -1,
103 [SNDRV_PCM_FORMAT_FLOAT64_LE] = {
104 .width = 64, .phys = 64, .le = 1, .signd = -1,
107 [SNDRV_PCM_FORMAT_FLOAT64_BE] = {
108 .width = 64, .phys = 64, .le = 0, .signd = -1,
111 [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE] = {
112 .width = 32, .phys = 32, .le = 1, .signd = -1,
115 [SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE] = {
116 .width = 32, .phys = 32, .le = 0, .signd = -1,
119 [SNDRV_PCM_FORMAT_MU_LAW] = {
120 .width = 8, .phys = 8, .le = -1, .signd = -1,
123 [SNDRV_PCM_FORMAT_A_LAW] = {
124 .width = 8, .phys = 8, .le = -1, .signd = -1,
127 [SNDRV_PCM_FORMAT_IMA_ADPCM] = {
128 .width = 4, .phys = 4, .le = -1, .signd = -1,
131 [SNDRV_PCM_FORMAT_G723_24] = {
132 .width = 3, .phys = 3, .le = -1, .signd = -1,
135 [SNDRV_PCM_FORMAT_G723_40] = {
136 .width = 5, .phys = 5, .le = -1, .signd = -1,
139 /* FIXME: the following three formats are not defined properly yet */
140 [SNDRV_PCM_FORMAT_MPEG] = {
141 .le = -1, .signd = -1,
143 [SNDRV_PCM_FORMAT_GSM] = {
144 .le = -1, .signd = -1,
146 [SNDRV_PCM_FORMAT_SPECIAL] = {
147 .le = -1, .signd = -1,
149 [SNDRV_PCM_FORMAT_S24_3LE] = {
150 .width = 24, .phys = 24, .le = 1, .signd = 1,
153 [SNDRV_PCM_FORMAT_S24_3BE] = {
154 .width = 24, .phys = 24, .le = 0, .signd = 1,
157 [SNDRV_PCM_FORMAT_U24_3LE] = {
158 .width = 24, .phys = 24, .le = 1, .signd = 0,
159 .silence = { 0x00, 0x00, 0x80 },
161 [SNDRV_PCM_FORMAT_U24_3BE] = {
162 .width = 24, .phys = 24, .le = 0, .signd = 0,
163 .silence = { 0x80, 0x00, 0x00 },
165 [SNDRV_PCM_FORMAT_S20_3LE] = {
166 .width = 20, .phys = 24, .le = 1, .signd = 1,
169 [SNDRV_PCM_FORMAT_S20_3BE] = {
170 .width = 20, .phys = 24, .le = 0, .signd = 1,
173 [SNDRV_PCM_FORMAT_U20_3LE] = {
174 .width = 20, .phys = 24, .le = 1, .signd = 0,
175 .silence = { 0x00, 0x00, 0x08 },
177 [SNDRV_PCM_FORMAT_U20_3BE] = {
178 .width = 20, .phys = 24, .le = 0, .signd = 0,
179 .silence = { 0x08, 0x00, 0x00 },
181 [SNDRV_PCM_FORMAT_S18_3LE] = {
182 .width = 18, .phys = 24, .le = 1, .signd = 1,
185 [SNDRV_PCM_FORMAT_S18_3BE] = {
186 .width = 18, .phys = 24, .le = 0, .signd = 1,
189 [SNDRV_PCM_FORMAT_U18_3LE] = {
190 .width = 18, .phys = 24, .le = 1, .signd = 0,
191 .silence = { 0x00, 0x00, 0x02 },
193 [SNDRV_PCM_FORMAT_U18_3BE] = {
194 .width = 18, .phys = 24, .le = 0, .signd = 0,
195 .silence = { 0x02, 0x00, 0x00 },
197 [SNDRV_PCM_FORMAT_G723_24_1B] = {
198 .width = 3, .phys = 8, .le = -1, .signd = -1,
201 [SNDRV_PCM_FORMAT_G723_40_1B] = {
202 .width = 5, .phys = 8, .le = -1, .signd = -1,
209 * snd_pcm_format_signed - Check the PCM format is signed linear
210 * @format: the format to check
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.
215 int snd_pcm_format_signed(snd_pcm_format_t format)
218 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
220 if ((val = pcm_formats[format].signd) < 0)
225 EXPORT_SYMBOL(snd_pcm_format_signed);
228 * snd_pcm_format_unsigned - Check the PCM format is unsigned linear
229 * @format: the format to check
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.
234 int snd_pcm_format_unsigned(snd_pcm_format_t format)
238 val = snd_pcm_format_signed(format);
244 EXPORT_SYMBOL(snd_pcm_format_unsigned);
247 * snd_pcm_format_linear - Check the PCM format is linear
248 * @format: the format to check
250 * Returns 1 if the given PCM format is linear, 0 if not.
252 int snd_pcm_format_linear(snd_pcm_format_t format)
254 return snd_pcm_format_signed(format) >= 0;
257 EXPORT_SYMBOL(snd_pcm_format_linear);
260 * snd_pcm_format_little_endian - Check the PCM format is little-endian
261 * @format: the format to check
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.
266 int snd_pcm_format_little_endian(snd_pcm_format_t format)
269 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
271 if ((val = pcm_formats[format].le) < 0)
276 EXPORT_SYMBOL(snd_pcm_format_little_endian);
279 * snd_pcm_format_big_endian - Check the PCM format is big-endian
280 * @format: the format to check
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.
285 int snd_pcm_format_big_endian(snd_pcm_format_t format)
289 val = snd_pcm_format_little_endian(format);
295 EXPORT_SYMBOL(snd_pcm_format_big_endian);
298 * snd_pcm_format_width - return the bit-width of the format
299 * @format: the format to check
301 * Returns the bit-width of the format, or a negative error code
304 int snd_pcm_format_width(snd_pcm_format_t format)
307 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
309 if ((val = pcm_formats[format].width) == 0)
314 EXPORT_SYMBOL(snd_pcm_format_width);
317 * snd_pcm_format_physical_width - return the physical bit-width of the format
318 * @format: the format to check
320 * Returns the physical bit-width of the format, or a negative error code
323 int snd_pcm_format_physical_width(snd_pcm_format_t format)
326 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
328 if ((val = pcm_formats[format].phys) == 0)
333 EXPORT_SYMBOL(snd_pcm_format_physical_width);
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
340 * Returns the byte size of the given samples for the format, or a
341 * negative error code if unknown format.
343 ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples)
345 int phys_width = snd_pcm_format_physical_width(format);
348 return samples * phys_width / 8;
351 EXPORT_SYMBOL(snd_pcm_format_size);
354 * snd_pcm_format_silence_64 - return the silent data in 8 bytes array
355 * @format: the format to check
357 * Returns the format pattern to fill or NULL if error.
359 const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format)
361 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
363 if (! pcm_formats[format].phys)
365 return pcm_formats[format].silence;
368 EXPORT_SYMBOL(snd_pcm_format_silence_64);
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
376 * Sets the silence data on the buffer for the given samples.
378 * Returns zero if successful, or a negative error code on failure.
380 int snd_pcm_format_set_silence(snd_pcm_format_t format, void *data, unsigned int samples)
383 unsigned char *dst, *pat;
385 if (format < 0 || format > SNDRV_PCM_FORMAT_LAST)
389 width = pcm_formats[format].phys; /* physical width */
390 pat = pcm_formats[format].silence;
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);
399 /* non-zero samples, fill using a loop */
404 memcpy(dst, pat, width);
408 /* a bit optimization for constant width */
439 EXPORT_SYMBOL(snd_pcm_format_set_silence);
442 * snd_pcm_limit_hw_rates - determine rate_min/rate_max fields
443 * @runtime: the runtime instance
445 * Determines the rate_min and rate_max fields from the rates bits of
446 * the given runtime->hw.
448 * Returns zero if successful.
450 int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime)
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];
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];
468 EXPORT_SYMBOL(snd_pcm_limit_hw_rates);
471 * snd_pcm_rate_to_rate_bit - converts sample rate to SNDRV_PCM_RATE_xxx bit
472 * @rate: the sample rate to convert
474 * Returns the SNDRV_PCM_RATE_xxx flag that corresponds to the given rate, or
475 * SNDRV_PCM_RATE_KNOT for an unknown rate.
477 unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate)
481 for (i = 0; i < snd_pcm_known_rates.count; i++)
482 if (snd_pcm_known_rates.list[i] == rate)
484 return SNDRV_PCM_RATE_KNOT;
486 EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit);