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
43struct 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
59int capturing = 1;
60
61unsigned 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
66void sigint_handler(int sig)
67{
68    capturing = 0;
69}
70
71int 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
183unsigned 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