/**
* Used for debugging purposes.
*/
public static void Print(TextWriter @out, TriangleFilter f)
{
for (int i = 0; i < f.left_edge_; ++i)
{
if (i != 0)
{
@out.Write(", ");
}
@out.Write("0");
}
for (int i = 0; i < f.size_; ++i)
{
//@out.Write(", " + f.filter_data_[i].ToString("0.000", CultureInfo.InvariantCulture));
@out.Write(", " + f.filter_data_[i].ToString(numberFormat));
}
}
public MelFilterBank(float min_freq, float max_freq, int num_mel_bands, int num_bins, int sample_rate, bool normalize_filter_area)
{
min_freq_ = min_freq;
max_freq_ = max_freq;
num_mel_bands_ = num_mel_bands;
num_bins_ = num_bins;
sample_rate_ = sample_rate;
normalize_filter_area_ = normalize_filter_area;
//Let's do some argument checking
if ((min_freq >= max_freq) || (max_freq == 0))
{
throw new Exception(String.Format("Invalid min/max frequencies for MelFilterBank: min = '{0}' max = '{1}'", min_freq, max_freq));
}
if (num_mel_bands == 0)
{
throw new Exception(String.Format("Invalid number of mel bands for MelFilterBank: n = {0}", num_mel_bands));
}
if (sample_rate == 0)
{
throw new Exception(String.Format("Invalid sample rate for MelFilterBank: s = {0}", sample_rate));
}
if (num_bins == 0)
{
throw new Exception(String.Format("Invalid number of bins for MelFilterBank: s = '{0}'", num_bins));
}
float delta_freq = (float)sample_rate_ / (2 *num_bins);
float mel_min = (float) HzToMel(min_freq_);
float mel_max = (float) HzToMel(max_freq_);
// We divide by #band + 1 as min / max should present the beginning / end
// of beginng up / ending low slope, i.e. it's not the centers of each
// band that represent min/max frequency in mel bands.
float delta_freq_mel = (mel_max - mel_min) / (num_mel_bands_ + 1);
// Fill up equidistant spacing in mel-space
float mel_left = mel_min;
for (int i = 0; i < num_mel_bands_; i++)
{
float mel_center = mel_left + delta_freq_mel;
float mel_right = mel_center + delta_freq_mel;
float left_hz = (float) MelToHz(mel_left);
float right_hz = (float) MelToHz(mel_right);
//align to closest num_bins (round)
int left_bin = (int)((left_hz / delta_freq) + 0.5f);
int right_bin = (int)((right_hz / delta_freq) + 0.5f);
//calculate normalized height
float height = 1.0f;
if (normalize_filter_area_)
height = 2.0f / (right_bin - left_bin);
// Create the actual filter
TriangleFilter fltr = new TriangleFilter(left_bin, right_bin, height);
filters_.Add(fltr);
//next left edge is current center
mel_left = mel_center;
}
}
public MelFilterBank(float min_freq, float max_freq, int num_mel_bands, int num_bins, int sample_rate, bool normalize_filter_area)
{
min_freq_ = min_freq;
max_freq_ = max_freq;
num_mel_bands_ = num_mel_bands;
num_bins_ = num_bins;
sample_rate_ = sample_rate;
normalize_filter_area_ = normalize_filter_area;
//Let's do some argument checking
if ((min_freq >= max_freq) || (max_freq == 0))
{
throw new Exception(String.Format("Invalid min/max frequencies for MelFilterBank: min = '{0}' max = '{1}'", min_freq, max_freq));
}
if (num_mel_bands == 0)
{
throw new Exception(String.Format("Invalid number of mel bands for MelFilterBank: n = {0}", num_mel_bands));
}
if (sample_rate == 0)
{
throw new Exception(String.Format("Invalid sample rate for MelFilterBank: s = {0}", sample_rate));
}
if (num_bins == 0)
{
throw new Exception(String.Format("Invalid number of bins for MelFilterBank: s = '{0}'", num_bins));
}
float delta_freq = (float)sample_rate_ / (2 * num_bins);
float mel_min = (float)HzToMel(min_freq_);
float mel_max = (float)HzToMel(max_freq_);
// We divide by #band + 1 as min / max should present the beginning / end
// of beginng up / ending low slope, i.e. it's not the centers of each
// band that represent min/max frequency in mel bands.
float delta_freq_mel = (mel_max - mel_min) / (num_mel_bands_ + 1);
// Fill up equidistant spacing in mel-space
float mel_left = mel_min;
for (int i = 0; i < num_mel_bands_; i++)
{
float mel_center = mel_left + delta_freq_mel;
float mel_right = mel_center + delta_freq_mel;
float left_hz = (float)MelToHz(mel_left);
float right_hz = (float)MelToHz(mel_right);
//align to closest num_bins (round)
int left_bin = (int)((left_hz / delta_freq) + 0.5f);
int right_bin = (int)((right_hz / delta_freq) + 0.5f);
//calculate normalized height
float height = 1.0f;
if (normalize_filter_area_)
{
height = 2.0f / (right_bin - left_bin);
}
// Create the actual filter
TriangleFilter fltr = new TriangleFilter(left_bin, right_bin, height);
filters_.Add(fltr);
//next left edge is current center
mel_left = mel_center;
}
}
/**
* Used for debugging purposes.
*/
public static void Print(TextWriter @out, TriangleFilter f)
{
for (int i = 0; i < f.left_edge_; ++i)
{
if (i != 0)
@out.Write(", ");
@out.Write("0");
}
for (int i = 0; i < f.size_; ++i)
{
//@out.Write(", " + f.filter_data_[i].ToString("0.000", CultureInfo.InvariantCulture));
@out.Write(", " + f.filter_data_[i].ToString(numberFormat));
}
}