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 */
29 #ifndef ASOUNDLIB_H
30 #define ASOUNDLIB_H
32 #include <sys/time.h>
33 #include <stddef.h>
35 #if defined(__cplusplus)
36 extern "C" {
37 #endif
39 /*
40 * PCM API
41 */
43 struct pcm;
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 */
59 /* PCM runtime states */
60 #define PCM_STATE_OPEN 0
61 #define PCM_STATE_SETUP 1
62 #define PCM_STATE_PREPARED 2
63 #define PCM_STATE_RUNNING 3
64 #define PCM_STATE_XRUN 4
65 #define PCM_STATE_DRAINING 5
66 #define PCM_STATE_PAUSED 6
67 #define PCM_STATE_SUSPENDED 7
68 #define PCM_STATE_DISCONNECTED 8
70 /* Bit formats */
71 enum pcm_format {
72 PCM_FORMAT_S16_LE = 0,
73 PCM_FORMAT_S32_LE,
74 PCM_FORMAT_S8,
75 PCM_FORMAT_S24_LE,
77 PCM_FORMAT_MAX,
78 };
80 /* Configuration for a stream */
81 struct pcm_config {
82 unsigned int channels;
83 unsigned int rate;
84 unsigned int period_size;
85 unsigned int period_count;
86 enum pcm_format format;
88 /* Values to use for the ALSA start, stop and silence thresholds. Setting
89 * any one of these values to 0 will cause the default tinyalsa values to be
90 * used instead. Tinyalsa defaults are as follows.
91 *
92 * start_threshold : period_count * period_size
93 * stop_threshold : period_count * period_size
94 * silence_threshold : 0
95 */
96 unsigned int start_threshold;
97 unsigned int stop_threshold;
98 unsigned int silence_threshold;
100 /* Minimum number of frames available before pcm_mmap_write() will actually
101 * write into the kernel buffer. Only used if the stream is opened in mmap mode
102 * (pcm_open() called with PCM_MMAP flag set). Use 0 for default.
103 */
104 int avail_min;
105 };
107 /* PCM parameters */
108 enum pcm_param
109 {
110 PCM_PARAM_SAMPLE_BITS,
111 PCM_PARAM_FRAME_BITS,
112 PCM_PARAM_CHANNELS,
113 PCM_PARAM_RATE,
114 PCM_PARAM_PERIOD_TIME,
115 PCM_PARAM_PERIOD_SIZE,
116 PCM_PARAM_PERIOD_BYTES,
117 PCM_PARAM_PERIODS,
118 PCM_PARAM_BUFFER_TIME,
119 PCM_PARAM_BUFFER_SIZE,
120 PCM_PARAM_BUFFER_BYTES,
121 PCM_PARAM_TICK_TIME,
122 };
124 /* Mixer control types */
125 enum mixer_ctl_type {
126 MIXER_CTL_TYPE_BOOL,
127 MIXER_CTL_TYPE_INT,
128 MIXER_CTL_TYPE_ENUM,
129 MIXER_CTL_TYPE_BYTE,
130 MIXER_CTL_TYPE_IEC958,
131 MIXER_CTL_TYPE_INT64,
132 MIXER_CTL_TYPE_UNKNOWN,
134 MIXER_CTL_TYPE_MAX,
135 };
137 /* Open and close a stream */
138 struct pcm *pcm_open(unsigned int card, unsigned int device,
139 unsigned int flags, struct pcm_config *config);
140 int pcm_close(struct pcm *pcm);
141 int pcm_is_ready(struct pcm *pcm);
143 /* Obtain the parameters for a PCM */
144 struct pcm_params *pcm_params_get(unsigned int card, unsigned int device,
145 unsigned int flags);
146 void pcm_params_free(struct pcm_params *pcm_params);
147 unsigned int pcm_params_get_min(struct pcm_params *pcm_params,
148 enum pcm_param param);
149 unsigned int pcm_params_get_max(struct pcm_params *pcm_params,
150 enum pcm_param param);
152 /* Set and get config */
153 int pcm_get_config(struct pcm *pcm, struct pcm_config *config);
154 int pcm_set_config(struct pcm *pcm, struct pcm_config *config);
156 /* Returns a human readable reason for the last error */
157 const char *pcm_get_error(struct pcm *pcm);
159 /* Returns the buffer size (int frames) that should be used for pcm_write. */
160 unsigned int pcm_get_buffer_size(struct pcm *pcm);
161 unsigned int pcm_frames_to_bytes(struct pcm *pcm, unsigned int frames);
162 unsigned int pcm_bytes_to_frames(struct pcm *pcm, unsigned int bytes);
164 /* Returns the pcm latency in ms */
165 unsigned int pcm_get_latency(struct pcm *pcm);
167 /* Returns available frames in pcm buffer and corresponding time stamp.
168 * For an input stream, frames available are frames ready for the
169 * application to read.
170 * For an output stream, frames available are the number of empty frames available
171 * for the application to write.
172 */
173 int pcm_get_htimestamp(struct pcm *pcm, unsigned int *avail,
174 struct timespec *tstamp);
176 /* Write data to the fifo.
177 * Will start playback on the first write or on a write that
178 * occurs after a fifo underrun.
179 */
180 int pcm_write(struct pcm *pcm, const void *data, unsigned int count);
181 int pcm_read(struct pcm *pcm, void *data, unsigned int count);
183 /*
184 * mmap() support.
185 */
186 int pcm_mmap_write(struct pcm *pcm, const void *data, unsigned int count);
187 int pcm_mmap_begin(struct pcm *pcm, void **areas, unsigned int *offset,
188 unsigned int *frames);
189 int pcm_mmap_commit(struct pcm *pcm, unsigned int offset, unsigned int frames);
191 /* Start and stop a PCM channel that doesn't transfer data */
192 int pcm_start(struct pcm *pcm);
193 int pcm_stop(struct pcm *pcm);
195 /* Interrupt driven API */
196 int pcm_wait(struct pcm *pcm, int timeout);
198 /* Change avail_min after the stream has been opened with no need to stop the stream.
199 * Only accepted if opened with PCM_MMAP and PCM_NOIRQ flags
200 */
201 int pcm_set_avail_min(struct pcm *pcm, int avail_min);
203 /*
204 * MIXER API
205 */
207 struct mixer;
208 struct mixer_ctl;
210 /* Open and close a mixer */
211 struct mixer *mixer_open(unsigned int card);
212 void mixer_close(struct mixer *mixer);
214 /* Obtain mixer controls */
215 unsigned int mixer_get_num_ctls(struct mixer *mixer);
216 struct mixer_ctl *mixer_get_ctl(struct mixer *mixer, unsigned int id);
217 struct mixer_ctl *mixer_get_ctl_by_name(struct mixer *mixer, const char *name);
219 /* Get info about mixer controls */
220 const char *mixer_ctl_get_name(struct mixer_ctl *ctl);
221 enum mixer_ctl_type mixer_ctl_get_type(struct mixer_ctl *ctl);
222 const char *mixer_ctl_get_type_string(struct mixer_ctl *ctl);
223 unsigned int mixer_ctl_get_num_values(struct mixer_ctl *ctl);
224 unsigned int mixer_ctl_get_num_enums(struct mixer_ctl *ctl);
225 const char *mixer_ctl_get_enum_string(struct mixer_ctl *ctl,
226 unsigned int enum_id);
228 /* Set and get mixer controls */
229 int mixer_ctl_get_percent(struct mixer_ctl *ctl, unsigned int id);
230 int mixer_ctl_set_percent(struct mixer_ctl *ctl, unsigned int id, int percent);
232 int mixer_ctl_get_value(struct mixer_ctl *ctl, unsigned int id);
233 int mixer_ctl_get_array(struct mixer_ctl *ctl, void *array, size_t count);
234 int mixer_ctl_set_value(struct mixer_ctl *ctl, unsigned int id, int value);
235 int mixer_ctl_set_array(struct mixer_ctl *ctl, const void *array, size_t count);
236 int mixer_ctl_set_enum_by_string(struct mixer_ctl *ctl, const char *string);
238 /* Determe range of integer mixer controls */
239 int mixer_ctl_get_range_min(struct mixer_ctl *ctl);
240 int mixer_ctl_get_range_max(struct mixer_ctl *ctl);
242 #if defined(__cplusplus)
243 } /* extern "C" */
244 #endif
246 #endif