Taylor Holberton | 5317e1c | 2016-12-04 13:17:53 -0800 | [diff] [blame] | 1 | #include <stdio.h> |
| 2 | #include <stdlib.h> |
| 3 | |
| 4 | #include <tinyalsa/pcm.h> |
| 5 | |
| 6 | static size_t read_frames(void **frames) |
| 7 | { |
| 8 | unsigned int card = 0; |
| 9 | unsigned int device = 0; |
| 10 | int flags = PCM_IN; |
| 11 | |
| 12 | const struct pcm_config config = { |
| 13 | .channels = 2, |
| 14 | .rate = 48000, |
| 15 | .format = PCM_FORMAT_S32_LE, |
| 16 | .period_size = 1024, |
| 17 | .period_count = 2, |
| 18 | .start_threshold = 1024, |
| 19 | .silence_threshold = 1024 * 2, |
| 20 | .stop_threshold = 1024 * 2 |
| 21 | }; |
| 22 | |
| 23 | struct pcm *pcm = pcm_open(card, device, flags, &config); |
| 24 | if (pcm == NULL) { |
| 25 | fprintf(stderr, "failed to allocate memory for PCM\n"); |
Taylor Holberton | 9ec09d5 | 2019-06-26 18:01:59 -0400 | [diff] [blame] | 26 | return 0; |
Taylor Holberton | 5317e1c | 2016-12-04 13:17:53 -0800 | [diff] [blame] | 27 | } else if (!pcm_is_ready(pcm)){ |
| 28 | pcm_close(pcm); |
| 29 | fprintf(stderr, "failed to open PCM\n"); |
Taylor Holberton | 9ec09d5 | 2019-06-26 18:01:59 -0400 | [diff] [blame] | 30 | return 0; |
Taylor Holberton | 5317e1c | 2016-12-04 13:17:53 -0800 | [diff] [blame] | 31 | } |
| 32 | |
| 33 | unsigned int frame_size = pcm_frames_to_bytes(pcm, 1); |
| 34 | unsigned int frames_per_sec = pcm_get_rate(pcm); |
| 35 | |
| 36 | *frames = malloc(frame_size * frames_per_sec); |
| 37 | if (*frames == NULL) { |
| 38 | fprintf(stderr, "failed to allocate frames\n"); |
| 39 | pcm_close(pcm); |
Taylor Holberton | 9ec09d5 | 2019-06-26 18:01:59 -0400 | [diff] [blame] | 40 | return 0; |
Taylor Holberton | 5317e1c | 2016-12-04 13:17:53 -0800 | [diff] [blame] | 41 | } |
| 42 | |
| 43 | int read_count = pcm_readi(pcm, *frames, frames_per_sec); |
| 44 | |
| 45 | size_t byte_count = pcm_frames_to_bytes(pcm, read_count); |
| 46 | |
| 47 | pcm_close(pcm); |
| 48 | |
| 49 | return byte_count; |
| 50 | } |
| 51 | |
| 52 | static int write_file(const void *frames, size_t size) |
| 53 | { |
| 54 | FILE *output_file = fopen("audio.raw", "wb"); |
| 55 | if (output_file == NULL) { |
| 56 | perror("failed to open 'audio.raw' for writing"); |
| 57 | return EXIT_FAILURE; |
| 58 | } |
| 59 | fwrite(frames, 1, size, output_file); |
| 60 | fclose(output_file); |
| 61 | return 0; |
| 62 | } |
| 63 | |
| 64 | int main(void) |
| 65 | { |
Taylor Holberton | 9ec09d5 | 2019-06-26 18:01:59 -0400 | [diff] [blame] | 66 | void *frames = NULL; |
| 67 | size_t size = 0; |
Taylor Holberton | 5317e1c | 2016-12-04 13:17:53 -0800 | [diff] [blame] | 68 | |
| 69 | size = read_frames(&frames); |
| 70 | if (size == 0) { |
| 71 | return EXIT_FAILURE; |
| 72 | } |
| 73 | |
| 74 | if (write_file(frames, size) < 0) { |
| 75 | free(frames); |
| 76 | return EXIT_FAILURE; |
| 77 | } |
| 78 | |
| 79 | free(frames); |
| 80 | |
| 81 | return EXIT_SUCCESS; |
| 82 | } |
| 83 | |