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#include <stdio.h>
#include <stdlib.h>
#include <tinyalsa/pcm.h>
static long int file_size(FILE * file)
{
if (fseek(file, 0, SEEK_END) < 0) {
return -1;
}
long int file_size = ftell(file);
if (fseek(file, 0, SEEK_SET) < 0) {
return -1;
}
return file_size;
}
static size_t read_file(void ** frames){
FILE * input_file = fopen("audio.raw", "rb");
if (input_file == NULL) {
perror("failed to open 'audio.raw' for writing");
return 0;
}
long int size = file_size(input_file);
if (size < 0) {
perror("failed to get file size of 'audio.raw'");
fclose(input_file);
return 0;
}
*frames = malloc(size);
if (*frames == NULL) {
fprintf(stderr, "failed to allocate frames\n");
fclose(input_file);
return 0;
}
size = fread(*frames, 1, size, input_file);
fclose(input_file);
return size;
}
static int write_frames(const void * frames, size_t byte_count){
unsigned int card = 0;
unsigned int device = 0;
int flags = PCM_OUT;
const struct pcm_config config = {
.channels = 2,
.rate = 48000,
.format = PCM_FORMAT_S32_LE,
.period_size = 1024,
.period_count = 2,
.start_threshold = 1024,
.silence_threshold = 1024 * 2,
.stop_threshold = 1024 * 2
};
struct pcm * pcm = pcm_open(card, device, flags, &config);
if (pcm == NULL) {
fprintf(stderr, "failed to allocate memory for PCM\n");
return -1;
} else if (!pcm_is_ready(pcm)){
pcm_close(pcm);
fprintf(stderr, "failed to open PCM\n");
return -1;
}
unsigned int frame_count = pcm_bytes_to_frames(pcm, byte_count);
int err = pcm_writei(pcm, frames, frame_count);
if (err != 0) {
printf("error: %s\n", pcm_get_error(pcm));
}
pcm_close(pcm);
return 0;
}
int main(void)
{
void *frames;
size_t size;
size = read_file(&frames);
if (size == 0) {
return EXIT_FAILURE;
}
if (write_frames(frames, size) < 0) {
return EXIT_FAILURE;
}
free(frames);
return EXIT_SUCCESS;
}
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