org.xiph.speex

Class Lsp


public class Lsp
extends java.lang.Object

Line Spectral Pair
Version:
$Revision: 1.2 $
Authors:
Jim Lawrence, helloNetwork.com
Marc Gimpel, Wimba S.A. (mgimpel@horizonwimba.com)

Field Summary

private float[]
pw

Constructor Summary

Lsp()
Constructor

Method Summary

static float
cheb_poly_eva(float[] coef, float x, int m)
This function evaluates a series of Chebyshev polynomials.
static void
enforce_margin(float[] lsp, int len, float margin)
Makes sure the LSPs are stable.
static int
lpc2lsp(float[] a, int lpcrdr, float[] freq, int nb, float delta)
This function converts LPC coefficients to LSP coefficients.
void
lsp2lpc(float[] freq, float[] ak, int lpcrdr)
Line Spectral Pair to Linear Prediction Coefficients

Field Details

pw

private float[] pw

Constructor Details

Lsp

public Lsp()
Constructor

Method Details

cheb_poly_eva

public static final float cheb_poly_eva(float[] coef,
                                        float x,
                                        int m)
This function evaluates a series of Chebyshev polynomials.
Parameters:
coef - - coefficients of the polynomial to be evaluated.
x - - the point where polynomial is to be evaluated.
m - - order of the polynomial.
Returns:
the value of the polynomial at point x.

enforce_margin

public static void enforce_margin(float[] lsp,
                                  int len,
                                  float margin)
Makes sure the LSPs are stable.
Parameters:
lsp -
len -
margin -

lpc2lsp

public static int lpc2lsp(float[] a,
                          int lpcrdr,
                          float[] freq,
                          int nb,
                          float delta)
This function converts LPC coefficients to LSP coefficients.
Parameters:
a - - LPC coefficients.
lpcrdr - - order of LPC coefficients (10).
freq - - LSP frequencies in the x domain.
nb - - number of sub-intervals (4).
delta - - grid spacing interval (0.02).
Returns:
the number of roots (the LSP coefs are returned in the array).

lsp2lpc

public void lsp2lpc(float[] freq,
                    float[] ak,
                    int lpcrdr)
Line Spectral Pair to Linear Prediction Coefficients
Parameters:
freq -
ak -
lpcrdr -

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