libsoundio  1.1.0
sio_microphone.c

Stream the default input device 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 <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
struct SoundIoRingBuffer *ring_buffer = NULL;
static enum SoundIoFormat prioritized_formats[] = {
SoundIoFormatFloat32NE,
SoundIoFormatFloat32FE,
SoundIoFormatS32NE,
SoundIoFormatS32FE,
SoundIoFormatS24NE,
SoundIoFormatS24FE,
SoundIoFormatS16NE,
SoundIoFormatS16FE,
SoundIoFormatFloat64NE,
SoundIoFormatFloat64FE,
SoundIoFormatU32NE,
SoundIoFormatU32FE,
SoundIoFormatU24NE,
SoundIoFormatU24FE,
SoundIoFormatU16NE,
SoundIoFormatU16FE,
};
static int prioritized_sample_rates[] = {
48000,
44100,
96000,
24000,
0,
};
__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 min_int(int a, int b) {
return (a < b) ? a : b;
}
static void read_callback(struct SoundIoInStream *instream, int frame_count_min, int frame_count_max) {
struct SoundIoChannelArea *areas;
int err;
char *write_ptr = soundio_ring_buffer_write_ptr(ring_buffer);
int free_bytes = soundio_ring_buffer_free_count(ring_buffer);
int free_count = free_bytes / instream->bytes_per_frame;
if (frame_count_min > free_count)
panic("ring buffer overflow");
int write_frames = min_int(free_count, frame_count_max);
int frames_left = write_frames;
for (;;) {
int frame_count = frames_left;
if ((err = soundio_instream_begin_read(instream, &areas, &frame_count)))
panic("begin read error: %s", soundio_strerror(err));
if (!frame_count)
break;
if (!areas) {
// Due to an overflow there is a hole. Fill the ring buffer with
// silence for the size of the hole.
memset(write_ptr, 0, frame_count * instream->bytes_per_frame);
fprintf(stderr, "Dropped %d frames due to internal overflow\n", frame_count);
} else {
for (int frame = 0; frame < frame_count; frame += 1) {
for (int ch = 0; ch < instream->layout.channel_count; ch += 1) {
memcpy(write_ptr, areas[ch].ptr, instream->bytes_per_sample);
areas[ch].ptr += areas[ch].step;
write_ptr += instream->bytes_per_sample;
}
}
}
if ((err = soundio_instream_end_read(instream)))
panic("end read error: %s", soundio_strerror(err));
frames_left -= frame_count;
if (frames_left <= 0)
break;
}
int advance_bytes = write_frames * instream->bytes_per_frame;
soundio_ring_buffer_advance_write_ptr(ring_buffer, advance_bytes);
}
static void write_callback(struct SoundIoOutStream *outstream, int frame_count_min, int frame_count_max) {
struct SoundIoChannelArea *areas;
int frame_count;
int err;
char *read_ptr = soundio_ring_buffer_read_ptr(ring_buffer);
int fill_bytes = soundio_ring_buffer_fill_count(ring_buffer);
int fill_count = fill_bytes / outstream->bytes_per_frame;
if (frame_count_min > fill_count) {
// Ring buffer does not have enough data, fill with zeroes.
for (;;) {
if ((err = soundio_outstream_begin_write(outstream, &areas, &frame_count)))
panic("begin write error: %s", soundio_strerror(err));
if (frame_count <= 0)
return;
for (int frame = 0; frame < frame_count; frame += 1) {
for (int ch = 0; ch < outstream->layout.channel_count; ch += 1) {
memset(areas[ch].ptr, 0, outstream->bytes_per_sample);
areas[ch].ptr += areas[ch].step;
}
}
if ((err = soundio_outstream_end_write(outstream)))
panic("end write error: %s", soundio_strerror(err));
}
}
int read_count = min_int(frame_count_max, fill_count);
int frames_left = read_count;
while (frames_left > 0) {
int frame_count = frames_left;
if ((err = soundio_outstream_begin_write(outstream, &areas, &frame_count)))
panic("begin write error: %s", soundio_strerror(err));
if (frame_count <= 0)
break;
for (int frame = 0; frame < frame_count; frame += 1) {
for (int ch = 0; ch < outstream->layout.channel_count; ch += 1) {
memcpy(areas[ch].ptr, read_ptr, outstream->bytes_per_sample);
areas[ch].ptr += areas[ch].step;
read_ptr += outstream->bytes_per_sample;
}
}
if ((err = soundio_outstream_end_write(outstream)))
panic("end write error: %s", soundio_strerror(err));
frames_left -= frame_count;
}
soundio_ring_buffer_advance_read_ptr(ring_buffer, read_count * outstream->bytes_per_frame);
}
static void underflow_callback(struct SoundIoOutStream *outstream) {
static int count = 0;
fprintf(stderr, "underflow %d\n", ++count);
}
static int usage(char *exe) {
fprintf(stderr, "Usage: %s [options]\n"
"Options:\n"
" [--backend dummy|alsa|pulseaudio|jack|coreaudio|wasapi]\n"
" [--in-device id]\n"
" [--in-raw]\n"
" [--out-device id]\n"
" [--out-raw]\n"
" [--latency seconds]\n"
, exe);
return 1;
}
int main(int argc, char **argv) {
char *exe = argv[0];
char *in_device_id = NULL;
char *out_device_id = NULL;
bool in_raw = false;
bool out_raw = false;
double microphone_latency = 0.2; // seconds
for (int i = 1; i < argc; i += 1) {
char *arg = argv[i];
if (arg[0] == '-' && arg[1] == '-') {
if (strcmp(arg, "--in-raw") == 0) {
in_raw = true;
} else if (strcmp(arg, "--out-raw") == 0) {
out_raw = true;
} else if (++i >= argc) {
return usage(exe);
} else if (strcmp(arg, "--backend") == 0) {
if (strcmp("dummy", argv[i]) == 0) {
} else if (strcmp("alsa", argv[i]) == 0) {
backend = SoundIoBackendAlsa;
} else if (strcmp("pulseaudio", argv[i]) == 0) {
} else if (strcmp("jack", argv[i]) == 0) {
backend = SoundIoBackendJack;
} else if (strcmp("coreaudio", argv[i]) == 0) {
} else if (strcmp("wasapi", argv[i]) == 0) {
} else {
fprintf(stderr, "Invalid backend: %s\n", argv[i]);
return 1;
}
} else if (strcmp(arg, "--in-device") == 0) {
in_device_id = argv[i];
} else if (strcmp(arg, "--out-device") == 0) {
out_device_id = argv[i];
} else if (strcmp(arg, "--latency") == 0) {
microphone_latency = atof(argv[i]);
} else {
return usage(exe);
}
} 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));
int default_out_device_index = soundio_default_output_device_index(soundio);
if (default_out_device_index < 0)
panic("no output device found");
int default_in_device_index = soundio_default_input_device_index(soundio);
if (default_in_device_index < 0)
panic("no input device found");
int in_device_index = default_in_device_index;
if (in_device_id) {
bool found = false;
for (int i = 0; i < soundio_input_device_count(soundio); i += 1) {
struct SoundIoDevice *device = soundio_get_input_device(soundio, i);
if (device->is_raw == in_raw && strcmp(device->id, in_device_id) == 0) {
in_device_index = i;
found = true;
break;
}
}
if (!found)
panic("invalid input device id: %s", in_device_id);
}
int out_device_index = default_out_device_index;
if (out_device_id) {
bool found = false;
for (int i = 0; i < soundio_output_device_count(soundio); i += 1) {
struct SoundIoDevice *device = soundio_get_output_device(soundio, i);
if (device->is_raw == out_raw && strcmp(device->id, out_device_id) == 0) {
out_device_index = i;
found = true;
break;
}
}
if (!found)
panic("invalid output device id: %s", out_device_id);
}
struct SoundIoDevice *out_device = soundio_get_output_device(soundio, out_device_index);
if (!out_device)
panic("could not get output device: out of memory");
struct SoundIoDevice *in_device = soundio_get_input_device(soundio, in_device_index);
if (!in_device)
panic("could not get input device: out of memory");
fprintf(stderr, "Input device: %s\n", in_device->name);
fprintf(stderr, "Output device: %s\n", out_device->name);
out_device->layouts, out_device->layout_count,
in_device->layouts, in_device->layout_count);
if (!layout)
panic("channel layouts not compatible");
int *sample_rate;
for (sample_rate = prioritized_sample_rates; *sample_rate; sample_rate += 1) {
if (soundio_device_supports_sample_rate(in_device, *sample_rate) &&
soundio_device_supports_sample_rate(out_device, *sample_rate))
{
break;
}
}
if (!*sample_rate)
panic("incompatible sample rates");
enum SoundIoFormat *fmt;
for (fmt = prioritized_formats; *fmt != SoundIoFormatInvalid; fmt += 1) {
if (soundio_device_supports_format(in_device, *fmt) &&
soundio_device_supports_format(out_device, *fmt))
{
break;
}
}
if (*fmt == SoundIoFormatInvalid)
panic("incompatible sample formats");
struct SoundIoInStream *instream = soundio_instream_create(in_device);
if (!instream)
panic("out of memory");
instream->format = *fmt;
instream->sample_rate = *sample_rate;
instream->layout = *layout;
instream->software_latency = microphone_latency;
if ((err = soundio_instream_open(instream))) {
fprintf(stderr, "unable to open input stream: %s", soundio_strerror(err));
return 1;
}
struct SoundIoOutStream *outstream = soundio_outstream_create(out_device);
if (!outstream)
panic("out of memory");
outstream->format = *fmt;
outstream->sample_rate = *sample_rate;
outstream->layout = *layout;
outstream->software_latency = microphone_latency;
if ((err = soundio_outstream_open(outstream))) {
fprintf(stderr, "unable to open output stream: %s", soundio_strerror(err));
return 1;
}
int capacity = microphone_latency * 2 * instream->sample_rate * instream->bytes_per_frame;
ring_buffer = soundio_ring_buffer_create(soundio, capacity);
if (!ring_buffer)
panic("unable to create ring buffer: out of memory");
char *buf = soundio_ring_buffer_write_ptr(ring_buffer);
int fill_count = microphone_latency * outstream->sample_rate * outstream->bytes_per_frame;
memset(buf, 0, fill_count);
soundio_ring_buffer_advance_write_ptr(ring_buffer, fill_count);
if ((err = soundio_instream_start(instream)))
panic("unable to start input device: %s", soundio_strerror(err));
if ((err = soundio_outstream_start(outstream)))
panic("unable to start output device: %s", soundio_strerror(err));
for (;;)
soundio_device_unref(out_device);
soundio_destroy(soundio);
return 0;
}