asoundlib.h revision 8863816dc5659a1e4678d17906c90844264d1588
1/* asoundlib.h 2** 3** Copyright 2011, The Android Open Source Project 4** 5** Redistribution and use in source and binary forms, with or without 6** modification, are permitted provided that the following conditions are met: 7** * Redistributions of source code must retain the above copyright 8** notice, this list of conditions and the following disclaimer. 9** * Redistributions in binary form must reproduce the above copyright 10** notice, this list of conditions and the following disclaimer in the 11** documentation and/or other materials provided with the distribution. 12** * Neither the name of The Android Open Source Project nor the names of 13** its contributors may be used to endorse or promote products derived 14** from this software without specific prior written permission. 15** 16** THIS SOFTWARE IS PROVIDED BY The Android Open Source Project ``AS IS'' AND 17** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19** ARE DISCLAIMED. IN NO EVENT SHALL The Android Open Source Project BE LIABLE 20** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 22** SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 23** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 26** DAMAGE. 27*/ 28 29#ifndef ASOUNDLIB_H 30#define ASOUNDLIB_H 31 32#include <sys/time.h> 33#include <stddef.h> 34 35#if defined(__cplusplus) 36extern "C" { 37#endif 38 39/* 40 * PCM API 41 */ 42 43struct pcm; 44 45#define PCM_OUT 0x00000000 46#define PCM_IN 0x10000000 47#define PCM_MMAP 0x00000001 48#define PCM_NOIRQ 0x00000002 49#define PCM_NORESTART 0x00000004 /* PCM_NORESTART - when set, calls to 50 * pcm_write for a playback stream will not 51 * attempt to restart the stream in the case 52 * of an underflow, but will return -EPIPE 53 * instead. After the first -EPIPE error, the 54 * stream is considered to be stopped, and a 55 * second call to pcm_write will attempt to 56 * restart the stream. 57 */ 58#define PCM_MONOTONIC 0x00000008 /* see pcm_get_htimestamp */ 59 60/* PCM runtime states */ 61#define PCM_STATE_OPEN 0 62#define PCM_STATE_SETUP 1 63#define PCM_STATE_PREPARED 2 64#define PCM_STATE_RUNNING 3 65#define PCM_STATE_XRUN 4 66#define PCM_STATE_DRAINING 5 67#define PCM_STATE_PAUSED 6 68#define PCM_STATE_SUSPENDED 7 69#define PCM_STATE_DISCONNECTED 8 70 71/* Bit formats */ 72enum pcm_format { 73 PCM_FORMAT_INVALID = -1, 74 PCM_FORMAT_S16_LE = 0, /* 16-bit signed */ 75 PCM_FORMAT_S32_LE, /* 32-bit signed */ 76 PCM_FORMAT_S8, /* 8-bit signed */ 77 PCM_FORMAT_S24_LE, /* 24-bits in 4-bytes */ 78 PCM_FORMAT_S24_3LE, /* 24-bits in 3-bytes */ 79 80 PCM_FORMAT_MAX, 81}; 82 83/* Bitmask has 256 bits (32 bytes) in asound.h */ 84struct pcm_mask { 85 unsigned int bits[32 / sizeof(unsigned int)]; 86}; 87 88/* Configuration for a stream */ 89struct pcm_config { 90 unsigned int channels; 91 unsigned int rate; 92 unsigned int period_size; 93 unsigned int period_count; 94 enum pcm_format format; 95 96 /* Values to use for the ALSA start, stop and silence thresholds. Setting 97 * any one of these values to 0 will cause the default tinyalsa values to be 98 * used instead. Tinyalsa defaults are as follows. 99 * 100 * start_threshold : period_count * period_size 101 * stop_threshold : period_count * period_size 102 * silence_threshold : 0 103 */ 104 unsigned int start_threshold; 105 unsigned int stop_threshold; 106 unsigned int silence_threshold; 107 108 /* Minimum number of frames available before pcm_mmap_write() will actually 109 * write into the kernel buffer. Only used if the stream is opened in mmap mode 110 * (pcm_open() called with PCM_MMAP flag set). Use 0 for default. 111 */ 112 int avail_min; 113}; 114 115/* PCM parameters */ 116enum pcm_param 117{ 118 /* mask parameters */ 119 PCM_PARAM_ACCESS, 120 PCM_PARAM_FORMAT, 121 PCM_PARAM_SUBFORMAT, 122 /* interval parameters */ 123 PCM_PARAM_SAMPLE_BITS, 124 PCM_PARAM_FRAME_BITS, 125 PCM_PARAM_CHANNELS, 126 PCM_PARAM_RATE, 127 PCM_PARAM_PERIOD_TIME, 128 PCM_PARAM_PERIOD_SIZE, 129 PCM_PARAM_PERIOD_BYTES, 130 PCM_PARAM_PERIODS, 131 PCM_PARAM_BUFFER_TIME, 132 PCM_PARAM_BUFFER_SIZE, 133 PCM_PARAM_BUFFER_BYTES, 134 PCM_PARAM_TICK_TIME, 135}; 136 137/* Mixer control types */ 138enum mixer_ctl_type { 139 MIXER_CTL_TYPE_BOOL, 140 MIXER_CTL_TYPE_INT, 141 MIXER_CTL_TYPE_ENUM, 142 MIXER_CTL_TYPE_BYTE, 143 MIXER_CTL_TYPE_IEC958, 144 MIXER_CTL_TYPE_INT64, 145 MIXER_CTL_TYPE_UNKNOWN, 146 147 MIXER_CTL_TYPE_MAX, 148}; 149 150/* Open and close a stream */ 151struct pcm *pcm_open(unsigned int card, unsigned int device, 152 unsigned int flags, struct pcm_config *config); 153int pcm_close(struct pcm *pcm); 154int pcm_is_ready(struct pcm *pcm); 155 156/* Obtain the parameters for a PCM */ 157struct pcm_params *pcm_params_get(unsigned int card, unsigned int device, 158 unsigned int flags); 159void pcm_params_free(struct pcm_params *pcm_params); 160 161struct pcm_mask *pcm_params_get_mask(struct pcm_params *pcm_params, 162 enum pcm_param param); 163unsigned int pcm_params_get_min(struct pcm_params *pcm_params, 164 enum pcm_param param); 165void pcm_params_set_min(struct pcm_params *pcm_params, 166 enum pcm_param param, unsigned int val); 167unsigned int pcm_params_get_max(struct pcm_params *pcm_params, 168 enum pcm_param param); 169void pcm_params_set_max(struct pcm_params *pcm_params, 170 enum pcm_param param, unsigned int val); 171 172/* Converts the pcm parameters to a human readable string. 173 * The string parameter is a caller allocated buffer of size bytes, 174 * which is then filled up to size - 1 and null terminated, 175 * if size is greater than zero. 176 * The return value is the number of bytes copied to string 177 * (not including null termination) if less than size; otherwise, 178 * the number of bytes required for the buffer. 179 */ 180int pcm_params_to_string(struct pcm_params *params, char *string, unsigned int size); 181 182/* Returns 1 if the pcm_format is present (format bit set) in 183 * the pcm_params structure; 0 otherwise, or upon unrecognized format. 184 */ 185int pcm_params_format_test(struct pcm_params *params, enum pcm_format format); 186 187/* Set and get config */ 188int pcm_get_config(struct pcm *pcm, struct pcm_config *config); 189int pcm_set_config(struct pcm *pcm, struct pcm_config *config); 190 191/* Returns a human readable reason for the last error */ 192const char *pcm_get_error(struct pcm *pcm); 193 194/* Returns the sample size in bits for a PCM format. 195 * As with ALSA formats, this is the storage size for the format, whereas the 196 * format represents the number of significant bits. For example, 197 * PCM_FORMAT_S24_LE uses 32 bits of storage. 198 */ 199unsigned int pcm_format_to_bits(enum pcm_format format); 200 201/* Returns the buffer size (int frames) that should be used for pcm_write. */ 202unsigned int pcm_get_buffer_size(struct pcm *pcm); 203unsigned int pcm_frames_to_bytes(struct pcm *pcm, unsigned int frames); 204unsigned int pcm_bytes_to_frames(struct pcm *pcm, unsigned int bytes); 205 206/* Returns the pcm latency in ms */ 207unsigned int pcm_get_latency(struct pcm *pcm); 208 209/* Returns available frames in pcm buffer and corresponding time stamp. 210 * The clock is CLOCK_MONOTONIC if flag PCM_MONOTONIC was specified in pcm_open, 211 * otherwise the clock is CLOCK_REALTIME. 212 * For an input stream, frames available are frames ready for the 213 * application to read. 214 * For an output stream, frames available are the number of empty frames available 215 * for the application to write. 216 */ 217int pcm_get_htimestamp(struct pcm *pcm, unsigned int *avail, 218 struct timespec *tstamp); 219 220/* Write data to the fifo. 221 * Will start playback on the first write or on a write that 222 * occurs after a fifo underrun. 223 */ 224int pcm_write(struct pcm *pcm, const void *data, unsigned int count); 225int pcm_read(struct pcm *pcm, void *data, unsigned int count); 226 227/* 228 * mmap() support. 229 */ 230int pcm_mmap_write(struct pcm *pcm, const void *data, unsigned int count); 231int pcm_mmap_read(struct pcm *pcm, void *data, unsigned int count); 232int pcm_mmap_begin(struct pcm *pcm, void **areas, unsigned int *offset, 233 unsigned int *frames); 234int pcm_mmap_commit(struct pcm *pcm, unsigned int offset, unsigned int frames); 235 236/* Prepare the PCM substream to be triggerable */ 237int pcm_prepare(struct pcm *pcm); 238/* Start and stop a PCM channel that doesn't transfer data */ 239int pcm_start(struct pcm *pcm); 240int pcm_stop(struct pcm *pcm); 241 242/* Interrupt driven API */ 243int pcm_wait(struct pcm *pcm, int timeout); 244 245/* Change avail_min after the stream has been opened with no need to stop the stream. 246 * Only accepted if opened with PCM_MMAP and PCM_NOIRQ flags 247 */ 248int pcm_set_avail_min(struct pcm *pcm, int avail_min); 249 250/* 251 * MIXER API 252 */ 253 254struct mixer; 255struct mixer_ctl; 256 257/* Open and close a mixer */ 258struct mixer *mixer_open(unsigned int card); 259void mixer_close(struct mixer *mixer); 260 261/* Get info about a mixer */ 262const char *mixer_get_name(struct mixer *mixer); 263 264/* Obtain mixer controls */ 265unsigned int mixer_get_num_ctls(struct mixer *mixer); 266struct mixer_ctl *mixer_get_ctl(struct mixer *mixer, unsigned int id); 267struct mixer_ctl *mixer_get_ctl_by_name(struct mixer *mixer, const char *name); 268 269/* Get info about mixer controls */ 270const char *mixer_ctl_get_name(struct mixer_ctl *ctl); 271enum mixer_ctl_type mixer_ctl_get_type(struct mixer_ctl *ctl); 272const char *mixer_ctl_get_type_string(struct mixer_ctl *ctl); 273unsigned int mixer_ctl_get_num_values(struct mixer_ctl *ctl); 274unsigned int mixer_ctl_get_num_enums(struct mixer_ctl *ctl); 275const char *mixer_ctl_get_enum_string(struct mixer_ctl *ctl, 276 unsigned int enum_id); 277 278/* Some sound cards update their controls due to external events, 279 * such as HDMI EDID byte data changing when an HDMI cable is 280 * connected. This API allows the count of elements to be updated. 281 */ 282void mixer_ctl_update(struct mixer_ctl *ctl); 283 284/* Set and get mixer controls */ 285int mixer_ctl_get_percent(struct mixer_ctl *ctl, unsigned int id); 286int mixer_ctl_set_percent(struct mixer_ctl *ctl, unsigned int id, int percent); 287 288int mixer_ctl_get_value(struct mixer_ctl *ctl, unsigned int id); 289int mixer_ctl_get_array(struct mixer_ctl *ctl, void *array, size_t count); 290int mixer_ctl_set_value(struct mixer_ctl *ctl, unsigned int id, int value); 291int mixer_ctl_set_array(struct mixer_ctl *ctl, const void *array, size_t count); 292int mixer_ctl_set_enum_by_string(struct mixer_ctl *ctl, const char *string); 293 294/* Determe range of integer mixer controls */ 295int mixer_ctl_get_range_min(struct mixer_ctl *ctl); 296int mixer_ctl_get_range_max(struct mixer_ctl *ctl); 297 298#if defined(__cplusplus) 299} /* extern "C" */ 300#endif 301 302#endif 303