libsoundio/example/sio_sine.c
2015-08-01 22:10:43 -07:00

142 lines
4.3 KiB
C

/*
* Copyright (c) 2015 Andrew Kelley
*
* This file is part of libsoundio, which is MIT licensed.
* See http://opensource.org/licenses/MIT
*/
#include <soundio/soundio.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
__attribute__ ((cold))
__attribute__ ((noreturn))
__attribute__ ((format (printf, 1, 2)))
static void panic(const char *format, ...) {
va_list ap;
va_start(ap, format);
vfprintf(stderr, format, ap);
fprintf(stderr, "\n");
va_end(ap);
abort();
}
static int usage(char *exe) {
fprintf(stderr, "Usage: %s [--dummy] [--alsa] [--pulseaudio] [--jack]\n", exe);
return 1;
}
static const float PI = 3.1415926535f;
static float seconds_offset = 0.0f;
static void write_callback(struct SoundIoOutStream *outstream, int requested_frame_count) {
float float_sample_rate = outstream->sample_rate;
float seconds_per_frame = 1.0f / float_sample_rate;
int err;
for (;;) {
int frame_count = requested_frame_count;
struct SoundIoChannelArea *areas;
if ((err = soundio_outstream_begin_write(outstream, &areas, &frame_count)))
panic("%s", soundio_strerror(err));
if (!frame_count)
break;
const struct SoundIoChannelLayout *layout = &outstream->layout;
float pitch = 440.0f;
float radians_per_second = pitch * 2.0f * PI;
for (int frame = 0; frame < frame_count; frame += 1) {
float sample = sinf((seconds_offset + frame * seconds_per_frame) * radians_per_second);
for (int channel = 0; channel < layout->channel_count; channel += 1) {
float *ptr = (float*)(areas[channel].ptr + areas[channel].step * frame);
*ptr = sample;
}
}
seconds_offset += seconds_per_frame * frame_count;
if ((err = soundio_outstream_end_write(outstream, frame_count))) {
if (err == SoundIoErrorUnderflow)
return;
panic("%s", soundio_strerror(err));
}
requested_frame_count -= frame_count;
if (requested_frame_count <= 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];
enum SoundIoBackend backend = SoundIoBackendNone;
for (int i = 1; i < argc; i += 1) {
char *arg = argv[i];
if (strcmp("--dummy", arg) == 0) {
backend = SoundIoBackendDummy;
} else if (strcmp("--alsa", arg) == 0) {
backend = SoundIoBackendAlsa;
} else if (strcmp("--pulseaudio", arg) == 0) {
backend = SoundIoBackendPulseAudio;
} else if (strcmp("--jack", arg) == 0) {
backend = SoundIoBackendJack;
} else {
return usage(exe);
}
}
struct SoundIo *soundio = soundio_create();
if (!soundio)
panic("out of memory");
int err = (backend == SoundIoBackendNone) ?
soundio_connect(soundio) : soundio_connect_backend(soundio, backend);
if (err)
panic("error connecting: %s", soundio_strerror(err));
soundio_flush_events(soundio);
int default_out_device_index = soundio_default_output_device_index(soundio);
if (default_out_device_index < 0)
panic("no output device found");
struct SoundIoDevice *device = soundio_get_output_device(soundio, default_out_device_index);
if (!device)
panic("out of memory");
fprintf(stderr, "Output device: %s\n", device->name);
struct SoundIoOutStream *outstream = soundio_outstream_create(device);
outstream->format = SoundIoFormatFloat32NE;
outstream->write_callback = write_callback;
outstream->underflow_callback = underflow_callback;
if ((err = soundio_outstream_open(outstream)))
panic("unable to open device: %s", soundio_strerror(err));
if (outstream->layout_error)
fprintf(stderr, "unable to set channel layout: %s\n", soundio_strerror(outstream->layout_error));
if ((err = soundio_outstream_start(outstream)))
panic("unable to start device: %s", soundio_strerror(err));
for (;;)
soundio_wait_events(soundio);
soundio_outstream_destroy(outstream);
soundio_device_unref(device);
soundio_destroy(soundio);
return 0;
}