1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <stdio.h>
18 #include <stdlib.h>
19 #include <stdint.h>
20 #include <signal.h>
21 #include <unistd.h>
22 #include <pthread.h>
23 #include <errno.h>
24 #include <string.h>
25
26 #include <tinyalsa/asoundlib.h>
27
28 #include <sys/types.h>
29 #include <sys/stat.h>
30 #include <fcntl.h>
31 #include <sys/ioctl.h>
32
33 #include "accessory.h"
34
35 #define BUFFER_COUNT 2
36 #define BUFFER_SIZE 16384
37
38 #define BUFFER_EMPTY 0
39 #define BUFFER_BUSY 1
40 #define BUFFER_FULL 2
41
42 static char* buffers[BUFFER_COUNT];
43 static int buffer_states[BUFFER_COUNT];
44 static int empty_index = 0;
45 static int full_index = -1;
46
47 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
48 static pthread_cond_t empty_cond = PTHREAD_COND_INITIALIZER;
49 static pthread_cond_t full_cond = PTHREAD_COND_INITIALIZER;
50
51 static unsigned int input_card;
52 static unsigned int input_device;
53
get_empty()54 static int get_empty()
55 {
56 int index, other;
57
58 pthread_mutex_lock(&mutex);
59
60 while (empty_index == -1)
61 pthread_cond_wait(&empty_cond, &mutex);
62
63 index = empty_index;
64 other = (index == 0 ? 1 : 0);
65 buffer_states[index] = BUFFER_BUSY;
66 if (buffer_states[other] == BUFFER_EMPTY)
67 empty_index = other;
68 else
69 empty_index = -1;
70
71 pthread_mutex_unlock(&mutex);
72 return index;
73 }
74
put_empty(int index)75 static void put_empty(int index)
76 {
77 pthread_mutex_lock(&mutex);
78
79 buffer_states[index] = BUFFER_EMPTY;
80 if (empty_index == -1) {
81 empty_index = index;
82 pthread_cond_signal(&empty_cond);
83 }
84
85 pthread_mutex_unlock(&mutex);
86 }
87
get_full()88 static int get_full()
89 {
90 int index, other;
91
92 pthread_mutex_lock(&mutex);
93
94 while (full_index == -1)
95 pthread_cond_wait(&full_cond, &mutex);
96
97 index = full_index;
98 other = (index == 0 ? 1 : 0);
99 buffer_states[index] = BUFFER_BUSY;
100 if (buffer_states[other] == BUFFER_FULL)
101 full_index = other;
102 else
103 full_index = -1;
104
105 pthread_mutex_unlock(&mutex);
106 return index;
107 }
108
put_full(int index)109 static void put_full(int index)
110 {
111 pthread_mutex_lock(&mutex);
112
113 buffer_states[index] = BUFFER_FULL;
114 if (full_index == -1) {
115 full_index = index;
116 pthread_cond_signal(&full_cond);
117 }
118
119 pthread_mutex_unlock(&mutex);
120 }
121
capture_thread(void * arg)122 static void* capture_thread(void* arg)
123 {
124 struct pcm_config config;
125 struct pcm *pcm = NULL;
126
127 fprintf(stderr, "capture_thread start\n");
128
129 memset(&config, 0, sizeof(config));
130
131 config.channels = 2;
132 config.rate = 44100;
133 config.period_size = 1024;
134 config.period_count = 4;
135 config.format = PCM_FORMAT_S16_LE;
136
137 while (1) {
138 while (!pcm) {
139 pcm = pcm_open(input_card, input_device, PCM_IN, &config);
140 if (pcm && !pcm_is_ready(pcm)) {
141 pcm_close(pcm);
142 pcm = NULL;
143 }
144 if (!pcm)
145 sleep(1);
146 }
147
148 while (pcm) {
149 int index = get_empty();
150 if (pcm_read(pcm, buffers[index], BUFFER_SIZE)) {
151 put_empty(index);
152 pcm_close(pcm);
153 pcm = NULL;
154 } else {
155 put_full(index);
156 }
157 }
158 }
159
160 fprintf(stderr, "capture_thread done\n");
161 return NULL;
162 }
163
play_thread(void * arg)164 static void* play_thread(void* arg)
165 {
166 struct pcm *pcm = arg;
167 int index, err;
168
169 fprintf(stderr, "play_thread start\n");
170
171 while (1) {
172 index = get_full();
173
174 err = pcm_write(pcm, buffers[index], BUFFER_SIZE);
175 if (err)
176 fprintf(stderr, "pcm_write err: %d\n", err);
177
178 put_empty(index);
179 }
180
181 fprintf(stderr, "play_thread done\n");
182 pcm_close(pcm);
183
184 return NULL;
185 }
186
init_audio(unsigned int ic,unsigned int id,unsigned int oc,unsigned int od)187 int init_audio(unsigned int ic, unsigned int id, unsigned int oc, unsigned int od)
188 {
189 pthread_t tid;
190 struct pcm_config config;
191 struct pcm *pcm;
192 int i;
193
194 input_card = ic;
195 input_device = id;
196
197 for (i = 0; i < BUFFER_COUNT; i++) {
198 buffers[i] = malloc(BUFFER_SIZE);
199 buffer_states[i] = BUFFER_EMPTY;
200 }
201
202 memset(&config, 0, sizeof(config));
203 config.channels = 2;
204 config.rate = 44100;
205 config.period_size = 1024;
206 config.period_count = 4;
207 config.format = PCM_FORMAT_S16_LE;
208
209 pcm = pcm_open(oc, od, PCM_OUT, &config);
210 if (!pcm || !pcm_is_ready(pcm)) {
211 fprintf(stderr, "Unable to open PCM device %d/%d for output (%s)\n",
212 oc, od, pcm_get_error(pcm));
213 return -1;
214 }
215
216 pthread_create(&tid, NULL, capture_thread, NULL);
217 pthread_create(&tid, NULL, play_thread, pcm);
218 return 0;
219 }
220