asoundlib.h revision c98da79067d89d934c4eb7de6a03e412eb421a5c
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_S16_LE = 0, 74 PCM_FORMAT_S32_LE, 75 PCM_FORMAT_S8, 76 PCM_FORMAT_S24_LE, 77 78 PCM_FORMAT_MAX, 79}; 80 81/* Configuration for a stream */ 82struct pcm_config { 83 unsigned int channels; 84 unsigned int rate; 85 unsigned int period_size; 86 unsigned int period_count; 87 enum pcm_format format; 88 89 /* Values to use for the ALSA start, stop and silence thresholds. Setting 90 * any one of these values to 0 will cause the default tinyalsa values to be 91 * used instead. Tinyalsa defaults are as follows. 92 * 93 * start_threshold : period_count * period_size 94 * stop_threshold : period_count * period_size 95 * silence_threshold : 0 96 */ 97 unsigned int start_threshold; 98 unsigned int stop_threshold; 99 unsigned int silence_threshold; 100 101 /* Minimum number of frames available before pcm_mmap_write() will actually 102 * write into the kernel buffer. Only used if the stream is opened in mmap mode 103 * (pcm_open() called with PCM_MMAP flag set). Use 0 for default. 104 */ 105 int avail_min; 106}; 107 108/* PCM parameters */ 109enum pcm_param 110{ 111 PCM_PARAM_SAMPLE_BITS, 112 PCM_PARAM_FRAME_BITS, 113 PCM_PARAM_CHANNELS, 114 PCM_PARAM_RATE, 115 PCM_PARAM_PERIOD_TIME, 116 PCM_PARAM_PERIOD_SIZE, 117 PCM_PARAM_PERIOD_BYTES, 118 PCM_PARAM_PERIODS, 119 PCM_PARAM_BUFFER_TIME, 120 PCM_PARAM_BUFFER_SIZE, 121 PCM_PARAM_BUFFER_BYTES, 122 PCM_PARAM_TICK_TIME, 123}; 124 125/* Mixer control types */ 126enum mixer_ctl_type { 127 MIXER_CTL_TYPE_BOOL, 128 MIXER_CTL_TYPE_INT, 129 MIXER_CTL_TYPE_ENUM, 130 MIXER_CTL_TYPE_BYTE, 131 MIXER_CTL_TYPE_IEC958, 132 MIXER_CTL_TYPE_INT64, 133 MIXER_CTL_TYPE_UNKNOWN, 134 135 MIXER_CTL_TYPE_MAX, 136}; 137 138/* Open and close a stream */ 139struct pcm *pcm_open(unsigned int card, unsigned int device, 140 unsigned int flags, struct pcm_config *config); 141int pcm_close(struct pcm *pcm); 142int pcm_is_ready(struct pcm *pcm); 143 144/* Obtain the parameters for a PCM */ 145struct pcm_params *pcm_params_get(unsigned int card, unsigned int device, 146 unsigned int flags); 147void pcm_params_free(struct pcm_params *pcm_params); 148unsigned int pcm_params_get_min(struct pcm_params *pcm_params, 149 enum pcm_param param); 150unsigned int pcm_params_get_max(struct pcm_params *pcm_params, 151 enum pcm_param param); 152 153/* Set and get config */ 154int pcm_get_config(struct pcm *pcm, struct pcm_config *config); 155int pcm_set_config(struct pcm *pcm, struct pcm_config *config); 156 157/* Returns a human readable reason for the last error */ 158const char *pcm_get_error(struct pcm *pcm); 159 160/* Returns the sample size in bits for a PCM format. 161 * As with ALSA formats, this is the storage size for the format, whereas the 162 * format represents the number of significant bits. For example, 163 * PCM_FORMAT_S24_LE uses 32 bits of storage. 164 */ 165unsigned int pcm_format_to_bits(enum pcm_format format); 166 167/* Returns the buffer size (int frames) that should be used for pcm_write. */ 168unsigned int pcm_get_buffer_size(struct pcm *pcm); 169unsigned int pcm_frames_to_bytes(struct pcm *pcm, unsigned int frames); 170unsigned int pcm_bytes_to_frames(struct pcm *pcm, unsigned int bytes); 171 172/* Returns the pcm latency in ms */ 173unsigned int pcm_get_latency(struct pcm *pcm); 174 175/* Returns available frames in pcm buffer and corresponding time stamp. 176 * The clock is CLOCK_MONOTONIC if flag PCM_MONOTONIC was specified in pcm_open, 177 * otherwise the clock is CLOCK_REALTIME. 178 * For an input stream, frames available are frames ready for the 179 * application to read. 180 * For an output stream, frames available are the number of empty frames available 181 * for the application to write. 182 */ 183int pcm_get_htimestamp(struct pcm *pcm, unsigned int *avail, 184 struct timespec *tstamp); 185 186/* Write data to the fifo. 187 * Will start playback on the first write or on a write that 188 * occurs after a fifo underrun. 189 */ 190int pcm_write(struct pcm *pcm, const void *data, unsigned int count); 191int pcm_read(struct pcm *pcm, void *data, unsigned int count); 192 193/* 194 * mmap() support. 195 */ 196int pcm_mmap_write(struct pcm *pcm, const void *data, unsigned int count); 197int pcm_mmap_read(struct pcm *pcm, void *data, unsigned int count); 198int pcm_mmap_begin(struct pcm *pcm, void **areas, unsigned int *offset, 199 unsigned int *frames); 200int pcm_mmap_commit(struct pcm *pcm, unsigned int offset, unsigned int frames); 201 202/* Start and stop a PCM channel that doesn't transfer data */ 203int pcm_start(struct pcm *pcm); 204int pcm_stop(struct pcm *pcm); 205 206/* Interrupt driven API */ 207int pcm_wait(struct pcm *pcm, int timeout); 208 209/* Change avail_min after the stream has been opened with no need to stop the stream. 210 * Only accepted if opened with PCM_MMAP and PCM_NOIRQ flags 211 */ 212int pcm_set_avail_min(struct pcm *pcm, int avail_min); 213 214/* 215 * MIXER API 216 */ 217 218struct mixer; 219struct mixer_ctl; 220 221/* Open and close a mixer */ 222struct mixer *mixer_open(unsigned int card); 223void mixer_close(struct mixer *mixer); 224 225/* Get info about a mixer */ 226const char *mixer_get_name(struct mixer *mixer); 227 228/* Obtain mixer controls */ 229unsigned int mixer_get_num_ctls(struct mixer *mixer); 230struct mixer_ctl *mixer_get_ctl(struct mixer *mixer, unsigned int id); 231struct mixer_ctl *mixer_get_ctl_by_name(struct mixer *mixer, const char *name); 232 233/* Get info about mixer controls */ 234const char *mixer_ctl_get_name(struct mixer_ctl *ctl); 235enum mixer_ctl_type mixer_ctl_get_type(struct mixer_ctl *ctl); 236const char *mixer_ctl_get_type_string(struct mixer_ctl *ctl); 237unsigned int mixer_ctl_get_num_values(struct mixer_ctl *ctl); 238unsigned int mixer_ctl_get_num_enums(struct mixer_ctl *ctl); 239const char *mixer_ctl_get_enum_string(struct mixer_ctl *ctl, 240 unsigned int enum_id); 241 242/* Some sound cards update their controls due to external events, 243 * such as HDMI EDID byte data changing when an HDMI cable is 244 * connected. This API allows the count of elements to be updated. 245 */ 246void mixer_ctl_update(struct mixer_ctl *ctl); 247 248/* Set and get mixer controls */ 249int mixer_ctl_get_percent(struct mixer_ctl *ctl, unsigned int id); 250int mixer_ctl_set_percent(struct mixer_ctl *ctl, unsigned int id, int percent); 251 252int mixer_ctl_get_value(struct mixer_ctl *ctl, unsigned int id); 253int mixer_ctl_get_array(struct mixer_ctl *ctl, void *array, size_t count); 254int mixer_ctl_set_value(struct mixer_ctl *ctl, unsigned int id, int value); 255int mixer_ctl_set_array(struct mixer_ctl *ctl, const void *array, size_t count); 256int mixer_ctl_set_enum_by_string(struct mixer_ctl *ctl, const char *string); 257 258/* Determe range of integer mixer controls */ 259int mixer_ctl_get_range_min(struct mixer_ctl *ctl); 260int mixer_ctl_get_range_max(struct mixer_ctl *ctl); 261 262#if defined(__cplusplus) 263} /* extern "C" */ 264#endif 265 266#endif 267