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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 #include <time.h>
36 
37 #define ID_RIFF 0x46464952
38 #define ID_WAVE 0x45564157
39 #define ID_FMT  0x20746d66
40 #define ID_DATA 0x61746164
41 
42 #define FORMAT_PCM 1
43 
44 struct wav_header {
45     uint32_t riff_id;
46     uint32_t riff_sz;
47     uint32_t riff_fmt;
48     uint32_t fmt_id;
49     uint32_t fmt_sz;
50     uint16_t audio_format;
51     uint16_t num_channels;
52     uint32_t sample_rate;
53     uint32_t byte_rate;
54     uint16_t block_align;
55     uint16_t bits_per_sample;
56     uint32_t data_id;
57     uint32_t data_sz;
58 };
59 
60 int capturing = 1;
61 
62 unsigned int capture_sample(FILE *file, unsigned int card, unsigned int device,
63                             unsigned int channels, unsigned int rate,
64                             enum pcm_format format, unsigned int period_size,
65                             unsigned int period_count, unsigned int cap_time);
66 
sigint_handler(int sig __unused)67 void sigint_handler(int sig __unused)
68 {
69     capturing = 0;
70 }
71 
main(int argc,char ** argv)72 int main(int argc, char **argv)
73 {
74     FILE *file;
75     struct wav_header header;
76     unsigned int card = 0;
77     unsigned int device = 0;
78     unsigned int channels = 2;
79     unsigned int rate = 44100;
80     unsigned int bits = 16;
81     unsigned int frames;
82     unsigned int period_size = 1024;
83     unsigned int period_count = 4;
84     unsigned int cap_time = 0;
85     enum pcm_format format;
86 
87     if (argc < 2) {
88         fprintf(stderr, "Usage: %s file.wav [-D card] [-d device]"
89                 " [-c channels] [-r rate] [-b bits] [-p period_size]"
90                 " [-n n_periods] [-T capture time]\n", argv[0]);
91         return 1;
92     }
93 
94     file = fopen(argv[1], "wb");
95     if (!file) {
96         fprintf(stderr, "Unable to create file '%s'\n", argv[1]);
97         return 1;
98     }
99 
100     /* parse command line arguments */
101     argv += 2;
102     while (*argv) {
103         if (strcmp(*argv, "-d") == 0) {
104             argv++;
105             if (*argv)
106                 device = atoi(*argv);
107         } else if (strcmp(*argv, "-c") == 0) {
108             argv++;
109             if (*argv)
110                 channels = atoi(*argv);
111         } else if (strcmp(*argv, "-r") == 0) {
112             argv++;
113             if (*argv)
114                 rate = atoi(*argv);
115         } else if (strcmp(*argv, "-b") == 0) {
116             argv++;
117             if (*argv)
118                 bits = atoi(*argv);
119         } else if (strcmp(*argv, "-D") == 0) {
120             argv++;
121             if (*argv)
122                 card = atoi(*argv);
123         } else if (strcmp(*argv, "-p") == 0) {
124             argv++;
125             if (*argv)
126                 period_size = atoi(*argv);
127         } else if (strcmp(*argv, "-n") == 0) {
128             argv++;
129             if (*argv)
130                 period_count = atoi(*argv);
131         } else if (strcmp(*argv, "-T") == 0) {
132             argv++;
133             if (*argv)
134                 cap_time = atoi(*argv);
135         }
136         if (*argv)
137             argv++;
138     }
139 
140     header.riff_id = ID_RIFF;
141     header.riff_sz = 0;
142     header.riff_fmt = ID_WAVE;
143     header.fmt_id = ID_FMT;
144     header.fmt_sz = 16;
145     header.audio_format = FORMAT_PCM;
146     header.num_channels = channels;
147     header.sample_rate = rate;
148 
149     switch (bits) {
150     case 32:
151         format = PCM_FORMAT_S32_LE;
152         break;
153     case 24:
154         format = PCM_FORMAT_S24_LE;
155         break;
156     case 16:
157         format = PCM_FORMAT_S16_LE;
158         break;
159     default:
160         fprintf(stderr, "%u bits is not supported.\n", bits);
161         fclose(file);
162         return 1;
163     }
164 
165     header.bits_per_sample = pcm_format_to_bits(format);
166     header.byte_rate = (header.bits_per_sample / 8) * channels * rate;
167     header.block_align = channels * (header.bits_per_sample / 8);
168     header.data_id = ID_DATA;
169 
170     /* leave enough room for header */
171     fseek(file, sizeof(struct wav_header), SEEK_SET);
172 
173     /* install signal handler and begin capturing */
174     signal(SIGINT, sigint_handler);
175     signal(SIGHUP, sigint_handler);
176     signal(SIGTERM, sigint_handler);
177     frames = capture_sample(file, card, device, header.num_channels,
178                             header.sample_rate, format,
179                             period_size, period_count, cap_time);
180     printf("Captured %u frames\n", frames);
181 
182     /* write header now all information is known */
183     header.data_sz = frames * header.block_align;
184     header.riff_sz = header.data_sz + sizeof(header) - 8;
185     fseek(file, 0, SEEK_SET);
186     fwrite(&header, sizeof(struct wav_header), 1, file);
187 
188     fclose(file);
189 
190     return 0;
191 }
192 
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,unsigned int cap_time)193 unsigned int capture_sample(FILE *file, unsigned int card, unsigned int device,
194                             unsigned int channels, unsigned int rate,
195                             enum pcm_format format, unsigned int period_size,
196                             unsigned int period_count, unsigned int cap_time)
197 {
198     struct pcm_config config;
199     struct pcm *pcm;
200     char *buffer;
201     unsigned int size;
202     unsigned int bytes_read = 0;
203     unsigned int frames = 0;
204     struct timespec end;
205     struct timespec now;
206 
207     memset(&config, 0, sizeof(config));
208     config.channels = channels;
209     config.rate = rate;
210     config.period_size = period_size;
211     config.period_count = period_count;
212     config.format = format;
213     config.start_threshold = 0;
214     config.stop_threshold = 0;
215     config.silence_threshold = 0;
216 
217     pcm = pcm_open(card, device, PCM_IN, &config);
218     if (!pcm || !pcm_is_ready(pcm)) {
219         fprintf(stderr, "Unable to open PCM device (%s)\n",
220                 pcm_get_error(pcm));
221         return 0;
222     }
223 
224     size = pcm_frames_to_bytes(pcm, pcm_get_buffer_size(pcm));
225     buffer = malloc(size);
226     if (!buffer) {
227         fprintf(stderr, "Unable to allocate %u bytes\n", size);
228         free(buffer);
229         pcm_close(pcm);
230         return 0;
231     }
232 
233     printf("Capturing sample: %u ch, %u hz, %u bit\n", channels, rate,
234            pcm_format_to_bits(format));
235 
236     clock_gettime(CLOCK_MONOTONIC, &now);
237     end.tv_sec = now.tv_sec + cap_time;
238     end.tv_nsec = now.tv_nsec;
239 
240     while (capturing && !pcm_read(pcm, buffer, size)) {
241         if (fwrite(buffer, 1, size, file) != size) {
242             fprintf(stderr,"Error capturing sample\n");
243             break;
244         }
245         bytes_read += size;
246         if (cap_time) {
247             clock_gettime(CLOCK_MONOTONIC, &now);
248             if (now.tv_sec > end.tv_sec ||
249                 (now.tv_sec == end.tv_sec && now.tv_nsec >= end.tv_nsec))
250                 break;
251         }
252     }
253 
254     frames = pcm_bytes_to_frames(pcm, bytes_read);
255     free(buffer);
256     pcm_close(pcm);
257     return frames;
258 }
259