marytts.signalproc.analysis

Class CepstrumLPCAnalyser

java.lang.Object

marytts.signalproc.analysis.CepstrumLPCAnalyser

public class CepstrumLPCAnalyser
extends Object

Author:

sacha Implements the conversion between the Linear Prediction Coefficients (LPC) and the corresponding Linear Prediction Cepstrum Coefficients.

Constructor Summary

Constructors

Constructor and Description
CepstrumLPCAnalyser()

Method Summary

Methods

Modifier and Type	Method and Description
static double[]	lpc2lpcc(double[] oneMinusA, double gain, int cepstrumOrder) Converts from LPC coefficients to LPCC coefficients.
static double[]	lpcc2lpc(double[] c, int lpcOrder) Converts from LPCC coefficients to LPC coefficients.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CepstrumLPCAnalyser

public CepstrumLPCAnalyser()

Method Detail

lpc2lpcc

public static double[] lpc2lpcc(double[] oneMinusA,
                double gain,
                int cepstrumOrder)

Converts from LPC coefficients to LPCC coefficients.

Parameters:

oneMinusA - A(z) = a0 - sum { ai * z^-i } . a0 = 1.

gain - The LPC gain factor.

cepstrumOrder - Cepstrum order (equal to the index of the last cepstrum coefficient).

Returns:

The LPCC coefficents. c[0] is set to log(gain).

lpcc2lpc

public static double[] lpcc2lpc(double[] c,
                int lpcOrder)

Converts from LPCC coefficients to LPC coefficients.

Parameters:

c - the vector of cepstral coefficients. Note: c[0] = log(gain).

lpcOrder - The original LPC order (equal to the index of the last LPC coefficient).

Returns:

The LPC coefficents [1 -a_1 -a_2 ... -a_p]. The gain is not returned, but it can be recovered as exp(c[0]).