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/*
* Copyright (C) 2015 Caleb Crome
* Copyright (C) 2013-2015 Intel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
/*
* This is a general purpose sine wave generator that will stay stable
* for a long time, and with a little renormalization, could stay stay
* stable indefinitely
*/
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <stdint.h>
#include <stdbool.h>
#include <errno.h>
#include "gettext.h"
#include "common.h"
#include "signal.h"
/*
* Initialize the sine wave generator.
* sin_generator: gets initialized by this call.
* frequency: the frequency for the sine wave. must be < 0.5*sample_rate
* sample_rate: the sample rate...
* returns 0 on success, -1 on error.
*/
int sin_generator_init(struct sin_generator *sg, float magnitude,
float frequency, float sample_rate)
{
/* angular frequency: cycles/sec / (samp/sec) * rad/cycle = rad/samp */
float w = frequency / sample_rate * 2 * M_PI;
if (frequency >= sample_rate / 2)
return -1;
sg->phasor_real = cos(w);
sg->phasor_imag = sin(w);
sg->magnitude = magnitude;
sg->state_real = 0.0;
sg->state_imag = magnitude;
sg->frequency = frequency;
sg->sample_rate = sample_rate;
return 0;
}
/*
* Generates the next sample in the sine wave.
* should be much faster than calling a sin function
* if it's inlined and optimized.
*
* returns the next value. no possibility of error.
*/
float sin_generator_next_sample(struct sin_generator *sg)
{
/* get shorthand to pointers */
const double pr = sg->phasor_real;
const double pi = sg->phasor_imag;
const double sr = sg->state_real;
const double si = sg->state_imag;
/* step the phasor -- complex multiply */
sg->state_real = sr * pr - si * pi;
sg->state_imag = sr * pi + pr * si;
/* return the input value so sine wave starts at exactly 0.0 */
return (float)sr;
}
/* fills a vector with a sine wave */
void sin_generator_vfill(struct sin_generator *sg, float *buf, int n)
{
int i;
for (i = 0; i < n; i++)
*buf++ = sin_generator_next_sample(sg);
}
static int reorder(struct bat *bat, float *val, int frames)
{
float *new_buf = NULL;
int i, c, bytes;
bytes = frames * bat->channels * sizeof(float);
new_buf = (float *) malloc(bytes);
if (new_buf == NULL) {
fprintf(bat->err, _("Not enough memory.\n"));
return -ENOMEM;
}
memcpy(new_buf, val, bytes);
for (i = 0; i < frames; i++)
for (c = 0; c < bat->channels; c++)
val[i * bat->channels + c] =
new_buf[c * frames + i];
free(new_buf);
return 0;
}
static int adjust_waveform(struct bat *bat, float *val, int frames,
int channels)
{
int i, nsamples, max;
float factor, offset = 0.0;
switch (bat->format) {
case BAT_PCM_FORMAT_U8:
max = INT8_MAX;
offset = max; /* shift for unsigned format */
break;
case BAT_PCM_FORMAT_S16_LE:
max = INT16_MAX;
break;
case BAT_PCM_FORMAT_S24_3LE:
max = (1 << 23) - 1;
break;
case BAT_PCM_FORMAT_S32_LE:
max = INT32_MAX;
break;
default:
fprintf(bat->err, _("Invalid PCM format: %d\n"), bat->format);
return -EINVAL;
}
factor = max * RANGE_FACTOR;
nsamples = channels * frames;
for (i = 0; i < nsamples; i++)
val[i] = val[i] * factor + offset;
return 0;
}
int generate_sine_wave(struct bat *bat, int frames, void *buf)
{
int err = 0;
int c, nsamples;
float *sinus_f = NULL;
static struct sin_generator sg[MAX_CHANNELS];
nsamples = bat->channels * frames;
sinus_f = (float *) malloc(nsamples * sizeof(float));
if (sinus_f == NULL) {
fprintf(bat->err, _("Not enough memory.\n"));
return -ENOMEM;
}
for (c = 0; c < bat->channels; c++) {
/* initialize static struct at the first time */
if (sg[c].frequency != bat->target_freq[c])
sin_generator_init(&sg[c], 1.0, bat->target_freq[c],
bat->rate);
/* fill buffer for each channel */
sin_generator_vfill(&sg[c], sinus_f + c * frames, frames);
}
/* reorder samples to interleaved mode */
err = reorder(bat, sinus_f, frames);
if (err != 0)
goto exit;
/* adjust amplitude and offset of waveform */
err = adjust_waveform(bat, sinus_f, frames, bat->channels);
if (err != 0)
goto exit;
bat->convert_float_to_sample(sinus_f, buf, frames, bat->channels);
exit:
free(sinus_f);
return err;
}
/* generate single channel sine waveform without sample conversion */
int generate_sine_wave_raw_mono(struct bat *bat, float *buf,
float freq, int nsamples)
{
int err = 0;
struct sin_generator sg;
err = sin_generator_init(&sg, 1.0, freq, bat->rate);
if (err < 0)
return err;
sin_generator_vfill(&sg, buf, nsamples);
/* adjust amplitude and offset of waveform */
err = adjust_waveform(bat, buf, nsamples, 1);
return err;
}
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