libsoundio  1.0.1
sio_sine.c

Play a sine wave over the default output device.Supports specifying device and backend to use.

/*
* Copyright (c) 2015 Andrew Kelley
*
* This file is part of libsoundio, which is MIT licensed.
* See http://opensource.org/licenses/MIT
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <math.h>
static int usage(char *exe) {
fprintf(stderr, "Usage: %s [options]\n"
"Options:\n"
" [--backend dummy|alsa|pulseaudio|jack|coreaudio|wasapi]\n"
" [--device id]\n"
" [--raw]\n"
" [--name stream_name]\n"
, exe);
return 1;
}
static void write_sample_s16ne(char *ptr, double sample) {
int16_t *buf = (int16_t *)ptr;
double range = (double)INT16_MAX - (double)INT16_MIN;
double val = sample * range / 2.0;
*buf = val;
}
static void write_sample_s32ne(char *ptr, double sample) {
int32_t *buf = (int32_t *)ptr;
double range = (double)INT32_MAX - (double)INT32_MIN;
double val = sample * range / 2.0;
*buf = val;
}
static void write_sample_float32ne(char *ptr, double sample) {
float *buf = (float *)ptr;
*buf = sample;
}
static void write_sample_float64ne(char *ptr, double sample) {
double *buf = (double *)ptr;
*buf = sample;
}
static void (*write_sample)(char *ptr, double sample);
static const double PI = 3.14159265358979323846264338328;
static double seconds_offset = 0.0;
static void write_callback(struct SoundIoOutStream *outstream, int frame_count_min, int frame_count_max) {
double float_sample_rate = outstream->sample_rate;
double seconds_per_frame = 1.0f / float_sample_rate;
struct SoundIoChannelArea *areas;
int err;
int frames_left = frame_count_max;
for (;;) {
int frame_count = frames_left;
if ((err = soundio_outstream_begin_write(outstream, &areas, &frame_count))) {
fprintf(stderr, "unrecoverable stream error: %s\n", soundio_strerror(err));
exit(1);
}
if (!frame_count)
break;
const struct SoundIoChannelLayout *layout = &outstream->layout;
double pitch = 440.0;
double radians_per_second = pitch * 2.0 * PI;
for (int frame = 0; frame < frame_count; frame += 1) {
double sample = sinf((seconds_offset + frame * seconds_per_frame) * radians_per_second);
for (int channel = 0; channel < layout->channel_count; channel += 1) {
write_sample(areas[channel].ptr, sample);
areas[channel].ptr += areas[channel].step;
}
}
seconds_offset += seconds_per_frame * frame_count;
if ((err = soundio_outstream_end_write(outstream))) {
return;
fprintf(stderr, "unrecoverable stream error: %s\n", soundio_strerror(err));
exit(1);
}
frames_left -= frame_count;
if (frames_left <= 0)
break;
}
}
static void underflow_callback(struct SoundIoOutStream *outstream) {
static int count = 0;
fprintf(stderr, "underflow %d\n", count++);
}
int main(int argc, char **argv) {
char *exe = argv[0];
char *device_id = NULL;
bool raw = false;
char *stream_name = NULL;
for (int i = 1; i < argc; i += 1) {
char *arg = argv[i];
if (arg[0] == '-' && arg[1] == '-') {
if (strcmp(arg, "--raw") == 0) {
raw = true;
} else {
i += 1;
if (i >= argc) {
return usage(exe);
} else if (strcmp(arg, "--backend") == 0) {
if (strcmp(argv[i], "dummy") == 0) {
} else if (strcmp(argv[i], "alsa") == 0) {
backend = SoundIoBackendAlsa;
} else if (strcmp(argv[i], "pulseaudio") == 0) {
} else if (strcmp(argv[i], "jack") == 0) {
backend = SoundIoBackendJack;
} else if (strcmp(argv[i], "coreaudio") == 0) {
} else if (strcmp(argv[i], "wasapi") == 0) {
} else {
fprintf(stderr, "Invalid backend: %s\n", argv[i]);
return 1;
}
} else if (strcmp(arg, "--device") == 0) {
device_id = argv[i];
} else if (strcmp(arg, "--name") == 0) {
stream_name = argv[i];
} else {
return usage(exe);
}
}
} else {
return usage(exe);
}
}
struct SoundIo *soundio = soundio_create();
if (!soundio) {
fprintf(stderr, "out of memory\n");
return 1;
}
int err = (backend == SoundIoBackendNone) ?
soundio_connect(soundio) : soundio_connect_backend(soundio, backend);
if (err) {
fprintf(stderr, "Unable to connect to backend: %s\n", soundio_strerror(err));
return 1;
}
fprintf(stderr, "Backend: %s\n", soundio_backend_name(soundio->current_backend));
int selected_device_index = -1;
if (device_id) {
int device_count = soundio_output_device_count(soundio);
for (int i = 0; i < device_count; i += 1) {
struct SoundIoDevice *device = soundio_get_output_device(soundio, i);
if (strcmp(device->id, device_id) == 0 && device->is_raw == raw) {
selected_device_index = i;
break;
}
}
} else {
selected_device_index = soundio_default_output_device_index(soundio);
}
if (selected_device_index < 0) {
fprintf(stderr, "Output device not found\n");
return 1;
}
struct SoundIoDevice *device = soundio_get_output_device(soundio, selected_device_index);
if (!device) {
fprintf(stderr, "out of memory\n");
return 1;
}
fprintf(stderr, "Output device: %s\n", device->name);
fprintf(stderr,
"'p\\n' - pause\n"
"'u\\n' - unpause\n"
"'c\\n' - clear buffer\n"
"'q\\n' - quit\n");
if (device->probe_error) {
fprintf(stderr, "Cannot probe device: %s\n", soundio_strerror(device->probe_error));
return 1;
}
struct SoundIoOutStream *outstream = soundio_outstream_create(device);
outstream->name = stream_name;
write_sample = write_sample_float32ne;
write_sample = write_sample_float64ne;
outstream->format = SoundIoFormatS32NE;
write_sample = write_sample_s32ne;
outstream->format = SoundIoFormatS16NE;
write_sample = write_sample_s16ne;
} else {
fprintf(stderr, "No suitable device format available.\n");
return 1;
}
if ((err = soundio_outstream_open(outstream))) {
fprintf(stderr, "unable to open device: %s", soundio_strerror(err));
return 1;
}
if (outstream->layout_error)
fprintf(stderr, "unable to set channel layout: %s\n", soundio_strerror(outstream->layout_error));
if ((err = soundio_outstream_start(outstream))) {
fprintf(stderr, "unable to start device: %s\n", soundio_strerror(err));
return 1;
}
for (;;) {
int c = getc(stdin);
if (c == 'p') {
fprintf(stderr, "pausing result: %s\n",
} else if (c == 'u') {
fprintf(stderr, "unpausing result: %s\n",
} else if (c == 'c') {
fprintf(stderr, "clear buffer result: %s\n",
} else if (c == 'q') {
break;
} else if (c == '\r' || c == '\n') {
// ignore
} else {
fprintf(stderr, "Unrecognized command: %c\n", c);
}
}
soundio_destroy(soundio);
return 0;
}