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