cheb_poly_eva
public static final float cheb_poly_eva(float[] coef,
float x,
int m)
This function evaluates a series of Chebyshev polynomials.
coef
- - coefficients of the polynomial to be evaluated.x
- - the point where polynomial is to be evaluated.m
- - order of the polynomial.
- 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.
lpc2lsp
public static int lpc2lsp(float[] a,
int lpcrdr,
float[] freq,
int nb,
float delta)
This function converts LPC coefficients to LSP coefficients.
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).
- 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