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 34 #if defined(__cplusplus) 35 extern "C" { 36 #endif 37 38 /* 39 * PCM API 40 */ 41 42 struct pcm; 43 44 #define PCM_OUT 0x00000000 45 #define PCM_IN 0x10000000 46 #define PCM_MMAP 0x00000001 47 #define PCM_NOIRQ 0x00000002 48 #define PCM_NORESTART 0x00000004 /* PCM_NORESTART - when set, calls to 49 * pcm_write for a playback stream will not 50 * attempt to restart the stream in the case 51 * of an underflow, but will return -EPIPE 52 * instead. After the first -EPIPE error, the 53 * stream is considered to be stopped, and a 54 * second call to pcm_write will attempt to 55 * restart the stream. 56 */ 57 58 /* PCM runtime states */ 59 #define PCM_STATE_OPEN 0 60 #define PCM_STATE_SETUP 1 61 #define PCM_STATE_PREPARED 2 62 #define PCM_STATE_RUNNING 3 63 #define PCM_STATE_XRUN 4 64 #define PCM_STATE_DRAINING 5 65 #define PCM_STATE_PAUSED 6 66 #define PCM_STATE_SUSPENDED 7 67 #define PCM_STATE_DISCONNECTED 8 68 69 /* Bit formats */ 70 enum pcm_format { 71 PCM_FORMAT_S16_LE = 0, 72 PCM_FORMAT_S32_LE, 73 74 PCM_FORMAT_MAX, 75 }; 76 77 /* Configuration for a stream */ 78 struct pcm_config { 79 unsigned int channels; 80 unsigned int rate; 81 unsigned int period_size; 82 unsigned int period_count; 83 enum pcm_format format; 84 85 /* Values to use for the ALSA start, stop and silence thresholds. Setting 86 * any one of these values to 0 will cause the default tinyalsa values to be 87 * used instead. Tinyalsa defaults are as follows. 88 * 89 * start_threshold : period_count * period_size 90 * stop_threshold : period_count * period_size 91 * silence_threshold : 0 92 */ 93 unsigned int start_threshold; 94 unsigned int stop_threshold; 95 unsigned int silence_threshold; 96 97 /* Minimum number of frames available before pcm_mmap_write() will actually 98 * write into the kernel buffer. Only used if the stream is opened in mmap mode 99 * (pcm_open() called with PCM_MMAP flag set). Use 0 for default. 100 */ 101 int avail_min; 102 }; 103 104 /* Mixer control types */ 105 enum mixer_ctl_type { 106 MIXER_CTL_TYPE_BOOL, 107 MIXER_CTL_TYPE_INT, 108 MIXER_CTL_TYPE_ENUM, 109 MIXER_CTL_TYPE_BYTE, 110 MIXER_CTL_TYPE_IEC958, 111 MIXER_CTL_TYPE_INT64, 112 MIXER_CTL_TYPE_UNKNOWN, 113 114 MIXER_CTL_TYPE_MAX, 115 }; 116 117 /* Open and close a stream */ 118 struct pcm *pcm_open(unsigned int card, unsigned int device, 119 unsigned int flags, struct pcm_config *config); 120 int pcm_close(struct pcm *pcm); 121 int pcm_is_ready(struct pcm *pcm); 122 123 /* Set and get config */ 124 int pcm_get_config(struct pcm *pcm, struct pcm_config *config); 125 int pcm_set_config(struct pcm *pcm, struct pcm_config *config); 126 127 /* Returns a human readable reason for the last error */ 128 const char *pcm_get_error(struct pcm *pcm); 129 130 /* Returns the buffer size (int frames) that should be used for pcm_write. */ 131 unsigned int pcm_get_buffer_size(struct pcm *pcm); 132 unsigned int pcm_frames_to_bytes(struct pcm *pcm, unsigned int frames); 133 unsigned int pcm_bytes_to_frames(struct pcm *pcm, unsigned int bytes); 134 135 /* Returns the pcm latency in ms */ 136 unsigned int pcm_get_latency(struct pcm *pcm); 137 138 /* Returns available frames in pcm buffer and corresponding time stamp. 139 * For an input stream, frames available are frames ready for the 140 * application to read. 141 * For an output stream, frames available are the number of empty frames available 142 * for the application to write. 143 */ 144 int pcm_get_htimestamp(struct pcm *pcm, unsigned int *avail, 145 struct timespec *tstamp); 146 147 /* Write data to the fifo. 148 * Will start playback on the first write or on a write that 149 * occurs after a fifo underrun. 150 */ 151 int pcm_write(struct pcm *pcm, const void *data, unsigned int count); 152 int pcm_read(struct pcm *pcm, void *data, unsigned int count); 153 154 /* 155 * mmap() support. 156 */ 157 int pcm_mmap_write(struct pcm *pcm, const void *data, unsigned int count); 158 int pcm_mmap_begin(struct pcm *pcm, void **areas, unsigned int *offset, 159 unsigned int *frames); 160 int pcm_mmap_commit(struct pcm *pcm, unsigned int offset, unsigned int frames); 161 162 /* Start and stop a PCM channel that doesn't transfer data */ 163 int pcm_start(struct pcm *pcm); 164 int pcm_stop(struct pcm *pcm); 165 166 /* Change avail_min after the stream has been opened with no need to stop the stream. 167 * Only accepted if opened with PCM_MMAP and PCM_NOIRQ flags 168 */ 169 int pcm_set_avail_min(struct pcm *pcm, int avail_min); 170 171 /* 172 * MIXER API 173 */ 174 175 struct mixer; 176 struct mixer_ctl; 177 178 /* Open and close a mixer */ 179 struct mixer *mixer_open(unsigned int card); 180 void mixer_close(struct mixer *mixer); 181 182 /* Obtain mixer controls */ 183 unsigned int mixer_get_num_ctls(struct mixer *mixer); 184 struct mixer_ctl *mixer_get_ctl(struct mixer *mixer, unsigned int id); 185 struct mixer_ctl *mixer_get_ctl_by_name(struct mixer *mixer, const char *name); 186 187 /* Get info about mixer controls */ 188 const char *mixer_ctl_get_name(struct mixer_ctl *ctl); 189 enum mixer_ctl_type mixer_ctl_get_type(struct mixer_ctl *ctl); 190 const char *mixer_ctl_get_type_string(struct mixer_ctl *ctl); 191 unsigned int mixer_ctl_get_num_values(struct mixer_ctl *ctl); 192 unsigned int mixer_ctl_get_num_enums(struct mixer_ctl *ctl); 193 const char *mixer_ctl_get_enum_string(struct mixer_ctl *ctl, 194 unsigned int enum_id); 195 196 /* Set and get mixer controls */ 197 int mixer_ctl_get_percent(struct mixer_ctl *ctl, unsigned int id); 198 int mixer_ctl_set_percent(struct mixer_ctl *ctl, unsigned int id, int percent); 199 200 int mixer_ctl_get_value(struct mixer_ctl *ctl, unsigned int id); 201 int mixer_ctl_set_value(struct mixer_ctl *ctl, unsigned int id, int value); 202 int mixer_ctl_set_enum_by_string(struct mixer_ctl *ctl, const char *string); 203 204 /* Determe range of integer mixer controls */ 205 int mixer_ctl_get_range_min(struct mixer_ctl *ctl); 206 int mixer_ctl_get_range_max(struct mixer_ctl *ctl); 207 208 #if defined(__cplusplus) 209 } /* extern "C" */ 210 #endif 211 212 #endif 213