sf_out.cc

// g++ -o /tmp/sf_out sf_out.cc -Wall -lsndfile

#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <sndfile.h>

int main (int argc, char** argv) 
{
	SF_INFO  _info;
	memset (&_info, 0, sizeof (_info));

	_info.channels = 1;
	_info.samplerate = 48000;
	_info.format = SF_FORMAT_WAV | SF_FORMAT_FLOAT;

	uint32_t n_samples = _info.samplerate * 4;
	uint32_t bpm = 120;

	uint32_t samples_per_beat = _info.samplerate * 60 / bpm;

	float* out = (float*) calloc (n_samples, sizeof (float));

	uint32_t p = 0;
	do {
		out[p] = 1.0;
		p += samples_per_beat;
	} while (p < n_samples);

	SNDFILE* sf_out = sf_open ("/tmp/out.wav", SFM_WRITE, &_info);
	sf_write_float (sf_out, out, n_samples);

	free (out);
	sf_close (sf_out);
}