void TransientIndex::initialize() {
dctMatrix = new double[filters * mels];
filterBank = new double[filters * spectrumSize];
filterTemp = new double[filters];
mfccNew = new double[mels];
mfccOld = new double[mels];
// Initialisation
double min_mel = hz_to_mel(50.0);
double max_mel = hz_to_mel(sampleRate / 2);
double* filter_values = new double[spectrumSize];
double* filter_centers = new double[filters + 2];
for (int i = 0; i < spectrumSize; i++)
filter_values[i] = double(sampleRate * i) / double(2 * (spectrumSize - 1));
for (int i = 0; i < mels; i++) {
for (int j = 0; j < filters; j++)
dctMatrix[i * filters + j] = cos((i + 1) * (PI / filters * (j + 0.5)));
}
for (int i = 0; i < filters + 2; i++)
filter_centers[i] = mel_to_hz(min_mel + ((max_mel - min_mel) / (filters + 1)) * i);
for (int i = 0; i < filters; i++) {
for (int j = 0; j < spectrumSize; j++) {
if (filter_values[j] >= filter_centers[i] && filter_values[j] < filter_centers[i + 1])
filterBank[(i * spectrumSize) + j] = (filter_values[j] - filter_centers[i]) / (filter_centers[i + 1] - filter_centers[i]);
else if (filter_values[j] >= filter_centers[i + 1] && filter_values[j] < filter_centers[i + 2])
filterBank[(i * spectrumSize) + j] = (filter_values[j] - filter_centers[i + 2]) / (filter_centers[i + 1] - filter_centers[i + 2]);
else
filterBank[(i * spectrumSize) + j] = 0;
}
}
for (int i = 0; i < mels; i++) {
mfccNew[i] = 0;
mfccOld[i] = 0;
}
for (int i = 0; i < filters; i++)
filterTemp[i] = 0;
delete[] filter_values;
delete[] filter_centers;
}
recur_bin_slopes_new(const int n_bins, const int fft_len,
const float fmin, const float fmax,
const float fknee, const float ffocus,
const float audio_rate){
const int n_slopes = n_bins + 1;
RecurAudioBinSlope * slopes = malloc_aligned_or_die(n_slopes *
sizeof(RecurAudioBinSlope));
int i;
const float mmin = hz_to_mel(fmin, fknee, ffocus);
const float mmax = hz_to_mel(fmax, fknee, ffocus);
const float step = (mmax - mmin) / n_slopes;
float hz_to_samples = fft_len * 2 / audio_rate;
float hz = fmin;
float mel = mmin;
float right = hz * hz_to_samples;
MAYBE_DEBUG("mmin %f mmax %f, fmin %f, fmax %f fknee %f ffocus %f",
mmin, mmax, fmin, fmax, fknee, ffocus);
for (i = 0; i < n_slopes; i++){
RecurAudioBinSlope *s = &slopes[i];
float left = right;
s->left = (int)left;
s->left_fraction = 1.0 - (left - s->left);
mel += step;
hz = mel_to_hz(mel, fknee, ffocus);
right = hz * hz_to_samples;
s->right = (int)right;
s->right_fraction = right - s->right;
s->slope = 1.0 / (right - left);
if (s->left == s->right){
/*triangle is too little! */
s->left_fraction = (right - left);
s->right_fraction = 0;
}
s->log_scale = logf(1.0f + right - left);
MAYBE_DEBUG("slope %d: left %d+%.2f right %d+%.2f log_scale %f hz %f"
" mel %f mmin %f mmax %f",
i, s->left, s->left_fraction, s->right, s->right_fraction, s->log_scale,
hz, mel, mmin, mmax);
}
return slopes;
}
