1 /* tinycap.c
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 #include <tinyalsa/asoundlib.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <stdint.h>
33 #include <signal.h>
34 #include <string.h>
35
36 #define ID_RIFF 0x46464952
37 #define ID_WAVE 0x45564157
38 #define ID_FMT 0x20746d66
39 #define ID_DATA 0x61746164
40
41 #define FORMAT_PCM 1
42
43 struct wav_header {
44 uint32_t riff_id;
45 uint32_t riff_sz;
46 uint32_t riff_fmt;
47 uint32_t fmt_id;
48 uint32_t fmt_sz;
49 uint16_t audio_format;
50 uint16_t num_channels;
51 uint32_t sample_rate;
52 uint32_t byte_rate;
53 uint16_t block_align;
54 uint16_t bits_per_sample;
55 uint32_t data_id;
56 uint32_t data_sz;
57 };
58
59 int capturing = 1;
60
61 unsigned int capture_sample(FILE *file, unsigned int card, unsigned int device,
62 unsigned int channels, unsigned int rate,
63 enum pcm_format format, unsigned int period_size,
64 unsigned int period_count);
65
sigint_handler(int sig)66 void sigint_handler(int sig)
67 {
68 capturing = 0;
69 }
70
main(int argc,char ** argv)71 int main(int argc, char **argv)
72 {
73 FILE *file;
74 struct wav_header header;
75 unsigned int card = 0;
76 unsigned int device = 0;
77 unsigned int channels = 2;
78 unsigned int rate = 44100;
79 unsigned int bits = 16;
80 unsigned int frames;
81 unsigned int period_size = 1024;
82 unsigned int period_count = 4;
83 enum pcm_format format;
84
85 if (argc < 2) {
86 fprintf(stderr, "Usage: %s file.wav [-D card] [-d device] [-c channels] "
87 "[-r rate] [-b bits] [-p period_size] [-n n_periods]\n", argv[0]);
88 return 1;
89 }
90
91 file = fopen(argv[1], "wb");
92 if (!file) {
93 fprintf(stderr, "Unable to create file '%s'\n", argv[1]);
94 return 1;
95 }
96
97 /* parse command line arguments */
98 argv += 2;
99 while (*argv) {
100 if (strcmp(*argv, "-d") == 0) {
101 argv++;
102 if (*argv)
103 device = atoi(*argv);
104 } else if (strcmp(*argv, "-c") == 0) {
105 argv++;
106 if (*argv)
107 channels = atoi(*argv);
108 } else if (strcmp(*argv, "-r") == 0) {
109 argv++;
110 if (*argv)
111 rate = atoi(*argv);
112 } else if (strcmp(*argv, "-b") == 0) {
113 argv++;
114 if (*argv)
115 bits = atoi(*argv);
116 } else if (strcmp(*argv, "-D") == 0) {
117 argv++;
118 if (*argv)
119 card = atoi(*argv);
120 } else if (strcmp(*argv, "-p") == 0) {
121 argv++;
122 if (*argv)
123 period_size = atoi(*argv);
124 } else if (strcmp(*argv, "-n") == 0) {
125 argv++;
126 if (*argv)
127 period_count = atoi(*argv);
128 }
129 if (*argv)
130 argv++;
131 }
132
133 header.riff_id = ID_RIFF;
134 header.riff_sz = 0;
135 header.riff_fmt = ID_WAVE;
136 header.fmt_id = ID_FMT;
137 header.fmt_sz = 16;
138 header.audio_format = FORMAT_PCM;
139 header.num_channels = channels;
140 header.sample_rate = rate;
141
142 switch (bits) {
143 case 32:
144 format = PCM_FORMAT_S32_LE;
145 break;
146 case 24:
147 format = PCM_FORMAT_S24_LE;
148 break;
149 case 16:
150 format = PCM_FORMAT_S16_LE;
151 break;
152 default:
153 fprintf(stderr, "%d bits is not supported.\n", bits);
154 return 1;
155 }
156
157 header.bits_per_sample = pcm_format_to_bits(format);
158 header.byte_rate = (header.bits_per_sample / 8) * channels * rate;
159 header.block_align = channels * (header.bits_per_sample / 8);
160 header.data_id = ID_DATA;
161
162 /* leave enough room for header */
163 fseek(file, sizeof(struct wav_header), SEEK_SET);
164
165 /* install signal handler and begin capturing */
166 signal(SIGINT, sigint_handler);
167 frames = capture_sample(file, card, device, header.num_channels,
168 header.sample_rate, format,
169 period_size, period_count);
170 printf("Captured %d frames\n", frames);
171
172 /* write header now all information is known */
173 header.data_sz = frames * header.block_align;
174 header.riff_sz = header.data_sz + sizeof(header) - 8;
175 fseek(file, 0, SEEK_SET);
176 fwrite(&header, sizeof(struct wav_header), 1, file);
177
178 fclose(file);
179
180 return 0;
181 }
182
capture_sample(FILE * file,unsigned int card,unsigned int device,unsigned int channels,unsigned int rate,enum pcm_format format,unsigned int period_size,unsigned int period_count)183 unsigned int capture_sample(FILE *file, unsigned int card, unsigned int device,
184 unsigned int channels, unsigned int rate,
185 enum pcm_format format, unsigned int period_size,
186 unsigned int period_count)
187 {
188 struct pcm_config config;
189 struct pcm *pcm;
190 char *buffer;
191 unsigned int size;
192 unsigned int bytes_read = 0;
193
194 config.channels = channels;
195 config.rate = rate;
196 config.period_size = period_size;
197 config.period_count = period_count;
198 config.format = format;
199 config.start_threshold = 0;
200 config.stop_threshold = 0;
201 config.silence_threshold = 0;
202
203 pcm = pcm_open(card, device, PCM_IN, &config);
204 if (!pcm || !pcm_is_ready(pcm)) {
205 fprintf(stderr, "Unable to open PCM device (%s)\n",
206 pcm_get_error(pcm));
207 return 0;
208 }
209
210 size = pcm_frames_to_bytes(pcm, pcm_get_buffer_size(pcm));
211 buffer = malloc(size);
212 if (!buffer) {
213 fprintf(stderr, "Unable to allocate %d bytes\n", size);
214 free(buffer);
215 pcm_close(pcm);
216 return 0;
217 }
218
219 printf("Capturing sample: %u ch, %u hz, %u bit\n", channels, rate,
220 pcm_format_to_bits(format));
221
222 while (capturing && !pcm_read(pcm, buffer, size)) {
223 if (fwrite(buffer, 1, size, file) != size) {
224 fprintf(stderr,"Error capturing sample\n");
225 break;
226 }
227 bytes_read += size;
228 }
229
230 free(buffer);
231 pcm_close(pcm);
232 return pcm_bytes_to_frames(pcm, bytes_read);
233 }
234
235