| #include <unistd.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <fcntl.h> |
| #include <errno.h> |
| #include <stdint.h> |
| #include <assert.h> |
| #include <string.h> |
| |
| #include <sys/ioctl.h> |
| |
| #define FAILIF(x, ...) do if (x) { \ |
| fprintf(stderr, __VA_ARGS__); \ |
| exit(EXIT_FAILURE); \ |
| } while (0) |
| |
| static char buffer[4096]; |
| |
| struct wav_header { |
| char riff[4]; |
| uint32_t chunk_size; |
| char format[4]; |
| |
| char subchunk1_id[4]; |
| 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; |
| |
| char subchunk2_id[4]; |
| uint32_t subchunk2_size; |
| } __attribute__((packed)); |
| |
| static void init_wav_header(struct wav_header *hdr, |
| uint32_t num_samples, |
| uint16_t bits_per_sample, |
| int channels, |
| uint32_t sample_rate) |
| { |
| hdr->riff[0] = 'R'; |
| hdr->riff[1] = 'I'; |
| hdr->riff[2] = 'F'; |
| hdr->riff[3] = 'F'; |
| |
| hdr->subchunk2_size = num_samples * channels * bits_per_sample / 8; |
| |
| hdr->chunk_size = 36 + hdr->subchunk2_size; |
| hdr->format[0] = 'W'; |
| hdr->format[1] = 'A'; |
| hdr->format[2] = 'V'; |
| hdr->format[3] = 'E'; |
| |
| hdr->subchunk1_id[0] = 'f'; |
| hdr->subchunk1_id[1] = 'm'; |
| hdr->subchunk1_id[2] = 't'; |
| hdr->subchunk1_id[3] = ' '; |
| |
| hdr->subchunk1_size = 16; |
| hdr->audio_format = 1; /* PCM */ |
| hdr->num_channels = channels; |
| hdr->sample_rate = sample_rate; |
| hdr->byte_rate = sample_rate * channels * bits_per_sample / 8; |
| hdr->block_align = channels * bits_per_sample / 8; |
| hdr->bits_per_sample = bits_per_sample; |
| |
| hdr->subchunk2_id[0] = 'd'; |
| hdr->subchunk2_id[1] = 'a'; |
| hdr->subchunk2_id[2] = 't'; |
| hdr->subchunk2_id[3] = 'a'; |
| } |
| |
| int |
| main(int argc, char *argv[]) |
| { |
| int ifd, ofd; |
| int nr, nw = 0, total = 0; |
| struct wav_header hdr; |
| |
| int opt; |
| char * output = NULL; |
| char * input = NULL; |
| int bits_per_sample = 16; |
| int sampling_rate = -1; |
| int num_channels = -1; |
| |
| while ((opt = getopt(argc, argv, "o:c:b:s:")) != -1) { |
| switch (opt) { |
| case 'o': |
| output = strdup(optarg); |
| break; |
| case 'c': |
| num_channels = atoi(optarg); |
| assert(num_channels == 1 || num_channels == 2); |
| break; |
| case 'b': |
| bits_per_sample = atoi(optarg); |
| break; |
| case 's': |
| sampling_rate = atoi(optarg); |
| break; |
| default: /* '?' */ |
| fprintf(stderr, "Usage: %s [-ooutfile] -c2 -b16 -s44100 infile\n", |
| argv[0]); |
| exit(EXIT_FAILURE); |
| } |
| } |
| |
| assert(sampling_rate >= 0); |
| assert(num_channels >= 0); |
| |
| FAILIF(!output, "Expecting an output file name\n"); |
| FAILIF(optind >= argc, "Expecting an input file name\n"); |
| |
| input = argv[optind]; |
| |
| printf("> input %s\n", input); |
| printf("> output %s\n", output); |
| printf("> bits per sample %d\n", bits_per_sample); |
| printf("> sampling rate %d\n", sampling_rate); |
| printf("> channels %d\n", num_channels); |
| |
| ofd = open(output, O_WRONLY | O_CREAT, 0777); |
| FAILIF(ofd < 0, "could not open %s: %s\n", output, strerror(errno)); |
| |
| ifd = open(input, O_RDONLY); |
| FAILIF(ifd < 0, "could not open %s: %s\n", input, strerror(errno)); |
| |
| lseek(ofd, sizeof(struct wav_header), SEEK_SET); |
| |
| do { |
| nr = read(ifd, buffer, sizeof(buffer)); |
| FAILIF(nr < 0, "Could not read from input: %s\n", strerror(errno)); |
| if (!nr) { |
| printf("done recording\n"); |
| break; |
| } |
| nw = write(ofd, buffer, nr); |
| FAILIF(nw < 0, "Could not copy to output: %s\n", strerror(errno)); |
| FAILIF(nw != nr, "Mismatch nw = %d nr = %d\n", nw, nr); |
| total += nw; |
| } while (1); |
| |
| printf("writing WAV header\n"); |
| lseek(ofd, 0, SEEK_SET); |
| init_wav_header(&hdr, |
| total * 8 / (num_channels * bits_per_sample), |
| bits_per_sample, |
| num_channels, |
| sampling_rate); |
| |
| FAILIF(write(ofd, &hdr, sizeof(hdr)) != sizeof(hdr), |
| "Could not write WAV header: %s\n", strerror(errno)); |
| |
| printf("done\n"); |
| return 0; |
| } |