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java.lang.Objectorg.oc.ocvolume.dsp.featureExtraction
public class featureExtraction
last updated on June 15, 2002
description: feature extraction class used to extract mel-frequency cepstral coefficients from input signal
calls: none
called by: volume, train
input: speech signal
output: mel-frequency cepstral coefficient
フィールドの概要 | |
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protected fft |
FFT
Fast Fourier Transformation |
protected static int |
fftSize
FFT Size (Must be be a power of 2) |
protected static int |
frameLength
Number of samples per frame |
protected double[][] |
frames
All the frames of the input signal |
protected double[] |
hammingWindow
hamming window values |
protected static double |
lowerFilterFreq
lower limit of filter (or 64 Hz?) |
int |
numCepstra
Number of MFCCs per frame Modifed 4/5/06 to be non final variable - Daniel McEnnnis |
protected static int |
numMelFilters
number of mel filters (SPHINX-III uses 40) |
protected static double |
preEmphasisAlpha
Pre-Emphasis Alpha (Set to 0 if no pre-emphasis should be performed) |
protected static int |
shiftInterval
Number of overlapping samples (usually 50% of frame length) |
protected static double |
upperFilterFreq
upper limit of filter (or half of sampling freq.?) |
コンストラクタの概要 | |
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featureExtraction()
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メソッドの概要 | |
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double[] |
cepCoefficients(double[] f)
Cepstral coefficients are calculated from the output of the Non-linear Transformation method calls: none called by: featureExtraction |
int[] |
fftBinIndices(double samplingRate,
int frameSize)
calculates the FFT bin indices calls: none called by: featureExtraction 5-3-05 Daniel MCEnnis paramaterize sampling rate and frameSize |
protected void |
framing(double[] inputSignal)
performs Frame Blocking to break down a speech signal into frames calls: none called by: featureExtraction |
protected static double |
freqToMel(double freq)
convert frequency to mel-frequency calls: none called by: featureExtraction |
protected static double |
log10(double value)
calculates logarithm with base 10 calls: none called by: featureExtraction |
double[] |
magnitudeSpectrum(double[] frame)
computes the magnitude spectrum of the input frame calls: none called by: featureExtraction |
double[] |
melFilter(double[] bin,
int[] cbin)
Calculate the output of the mel filter calls: none called by: featureExtraction |
double[] |
nonLinearTransformation(double[] fbank)
the output of mel filtering is subjected to a logarithm function (natural logarithm) calls: none called by: featureExtraction |
protected static double[] |
preEmphasis(short[] inputSignal)
perform pre-emphasis to equalize amplitude of high and low frequency calls: none called by: featureExtraction |
double[][] |
process(short[] inputSignal,
double samplingRate)
takes a speech signal and returns the Mel-Frequency Cepstral Coefficient (MFCC) calls: fft called by: volume, train 5-3-05 Daniel McEnnis - paramatrized sampling rate. |
クラス java.lang.Object から継承されたメソッド |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
フィールドの詳細 |
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protected static final int frameLength
protected static final int shiftInterval
public int numCepstra
protected static final int fftSize
protected static final double preEmphasisAlpha
protected static final double lowerFilterFreq
protected static final double upperFilterFreq
protected static final int numMelFilters
protected double[][] frames
protected double[] hammingWindow
protected fft FFT
コンストラクタの詳細 |
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public featureExtraction()
メソッドの詳細 |
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public double[][] process(short[] inputSignal, double samplingRate)
inputSignal
- Speech Waveform (16 bit integer data)
public int[] fftBinIndices(double samplingRate, int frameSize)
public double[] melFilter(double[] bin, int[] cbin)
public double[] cepCoefficients(double[] f)
f
- Output of the Non-linear Transformation method
public double[] nonLinearTransformation(double[] fbank)
fbank
- Output of mel filtering
protected static double log10(double value)
value
- Number to take the log of
protected static double freqToMel(double freq)
freq
- Frequency
public double[] magnitudeSpectrum(double[] frame)
frame
- Input frame signal
protected void framing(double[] inputSignal)
inputSignal
- Speech Signal (16 bit integer data)protected static double[] preEmphasis(short[] inputSignal)
inputSignal
- Speech Signal (16 bit integer data)
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前のクラス 次のクラス | フレームあり フレームなし | ||||||||
概要: 入れ子 | フィールド | コンストラクタ | メソッド | 詳細: フィールド | コンストラクタ | メソッド |