| #define _BSD_SOURCE |
| #include <endian.h> |
| #include <fcntl.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| typedef struct WAV_hdr |
| { |
| uint32_t chunk_id; |
| uint32_t chunk_size; |
| uint32_t format; |
| |
| uint32_t subchunk1_id; |
| uint32_t subchunk1_size; |
| uint16_t audio_format; |
| uint16_t num_channels; |
| uint32_t sample_rate; |
| uint32_t byte_rate; |
| uint16_t block_align; |
| uint16_t bits_per_sample; |
| |
| uint32_t subchunk2_id; |
| uint32_t subchunk2_size; |
| } WAV_hdr_t; |
| |
| |
| static int usage(const char *progname) |
| { |
| fprintf(stderr, "usage: %s [-f outfile]\n, where:", progname); |
| fprintf(stderr, "\t-f outfile: file to write audio to in WAV format.\n"); |
| exit(1); |
| } |
| |
| |
| int main(int argc, char **argv) |
| { |
| mode_t mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP; |
| int fd; |
| const char *outfile = "/tmp/audio.wav"; |
| int outfd; |
| uint8_t buf[8192]; |
| WAV_hdr_t hdr; |
| ssize_t len, totlen=0; |
| int num_no_data = -1; |
| int c; |
| |
| memset(buf, 0, sizeof(buf)); |
| memset(&hdr, 0, sizeof(hdr)); |
| |
| while ((c = getopt(argc, argv, "f:")) != -1) { |
| switch (c) { |
| case 'f': |
| outfile = optarg; |
| break; |
| default: |
| usage(argv[0]); |
| break; |
| } |
| } |
| |
| if ((fd = open("/tmp/rcu_audio_pcm", O_RDONLY)) < 0) { |
| perror("open /tmp/rcu_audio_pcm"); |
| exit(1); |
| } |
| |
| if ((outfd = open(outfile, O_RDWR|O_CREAT|O_TRUNC, mode)) < 0) { |
| fprintf(stderr, "Unable to open %s for writing.\n", outfile); |
| exit(1); |
| } |
| |
| if ((len = write(outfd, &hdr, sizeof(WAV_hdr_t))) != sizeof(WAV_hdr_t)) { |
| fprintf(stderr, "Incorrect size for WAV header: %zd != %zd\n", |
| len, sizeof(WAV_hdr_t)); |
| exit(1); |
| } |
| |
| while (1) { |
| len = read(fd, buf, sizeof(buf)); |
| if (len > 0) { |
| totlen += len; |
| if (write(outfd, buf, len) != len) { |
| fprintf(stderr, "short write!\n"); |
| exit(1); |
| } |
| num_no_data = 0; |
| } else if (len < 0) { |
| perror("read"); |
| exit(1); |
| } else if (len == 0) { |
| if (num_no_data >= 5) { |
| break; |
| } |
| sleep(1); |
| if (num_no_data >= 0) { |
| num_no_data++; |
| } |
| } |
| } |
| |
| lseek(outfd, 0, SEEK_SET); |
| |
| #define BITS_PER_SAMPLE 16 |
| #define SAMPLES_PER_SECOND 16000 |
| /* http://soundfile.sapp.org/doc/WaveFormat/ */ |
| hdr.chunk_id = htole32(0x46464952); // "RIFF" |
| hdr.chunk_size = htole32(36 + totlen); |
| hdr.format = htole32(0x45564157); // "WAVE" |
| |
| hdr.subchunk1_id = htole32(0x20746d66); // "fmt " |
| hdr.subchunk1_size = htole32(16); |
| hdr.audio_format = htole16(1); |
| hdr.num_channels = htole16(1); |
| hdr.sample_rate = htole32(SAMPLES_PER_SECOND); |
| hdr.byte_rate = htole32(SAMPLES_PER_SECOND * 1 * BITS_PER_SAMPLE/8); |
| hdr.block_align = htole16(1 * BITS_PER_SAMPLE/8); |
| hdr.bits_per_sample = htole16(BITS_PER_SAMPLE); |
| |
| hdr.subchunk2_id = htole32(0x61746164); // "data" |
| hdr.subchunk2_size = htole32(totlen); |
| if ((len = write(outfd, &hdr, sizeof(WAV_hdr_t))) != sizeof(WAV_hdr_t)) { |
| fprintf(stderr, "Incorrect size for WAV header: %zd != %zd\n", |
| len, sizeof(WAV_hdr_t)); |
| exit(1); |
| } |
| |
| exit(0); |
| } |