net.java.sip.communicator.impl.media.codec.audio.g729
Class Lpcfunc

java.lang.Object
  net.java.sip.communicator.impl.media.codec.audio.g729.Lpcfunc

 class Lpcfunc
extends Object

Author:

Lubomir Marinov (translation of ITU-T C source code to Java)

Constructor Summary

Lpcfunc()

Method Summary

(package private) static void	int_lpc(float[] lsp_old, float[] lsp_new, float[] lsf_int, float[] lsf_new, float[] az) Interpolated M LSP parameters and convert to M+1 LPC coeffs
(package private) static void	int_qlpc(float[] lsp_old, float[] lsp_new, float[] az) Interpolated M LSP parameters and convert to M+1 LPC coeffs
(package private) static void	lsf_lsp(float[] lsf, float[] lsp, int m) Convert from lsf[0..M-1 to lsp[0..M-1]
(package private) static void	lsp_lsf(float[] lsp, float[] lsf, int m) Convert from lsp[0..M-1 to lsf[0..M-1]
(package private) static void	weight_az(float[] a, int a_offset, float gamma, int m, float[] ap) Weighting of LPC coefficients ap[i] = a[i] * (gamma ** i)

Methods inherited from class java.lang.Object

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

Constructor Detail

Lpcfunc

Lpcfunc()

Method Detail

lsf_lsp

static void lsf_lsp(float[] lsf,
                    float[] lsp,
                    int m)

Convert from lsf[0..M-1 to lsp[0..M-1]

Parameters:

lsf - input : lsf

lsp - output: lsp

m - input : length

lsp_lsf

static void lsp_lsf(float[] lsp,
                    float[] lsf,
                    int m)

Convert from lsp[0..M-1 to lsf[0..M-1]

Parameters:

lsp - input : lsp coefficients

lsf - output: lsf (normalized frequencies

m - input: length

weight_az

static void weight_az(float[] a,
                      int a_offset,
                      float gamma,
                      int m,
                      float[] ap)

Weighting of LPC coefficients ap[i] = a[i] * (gamma ** i)

Parameters:

a - input : lpc coefficients a[0:m]

a_offset - input : lpc coefficients offset

gamma - input : weighting factor

m - input : filter order

ap - output: weighted coefficients ap[0:m]

int_qlpc

static void int_qlpc(float[] lsp_old,
                     float[] lsp_new,
                     float[] az)

Interpolated M LSP parameters and convert to M+1 LPC coeffs

Parameters:

lsp_old - input : LSPs for past frame (0:M-1)

lsp_new - input : LSPs for present frame (0:M-1)

az - output: filter parameters in 2 subfr (dim 2(m+1))

int_lpc

static void int_lpc(float[] lsp_old,
                    float[] lsp_new,
                    float[] lsf_int,
                    float[] lsf_new,
                    float[] az)

Interpolated M LSP parameters and convert to M+1 LPC coeffs

Parameters:

lsp_old - input : LSPs for past frame (0:M-1)

lsp_new - input : LSPs for present frame (0:M-1)

lsf_int - output: interpolated lsf coefficients

lsf_new - input : LSFs for present frame (0:M-1)

az - output: filter parameters in 2 subfr (dim 2(m+1))