Package org.xiph.speex

Class Filters

java.lang.Object

org.xiph.speex.Filters

public class Filters
extends java.lang.Object

Filters

Version:

$Revision: 1.2 $

Author:

Jim Lawrence, helloNetwork.com, Marc Gimpel, Wimba S.A. (mgimpel@horizonwimba.com)

Field Summary

Fields

Modifier and Type	Field	Description
private int	last_pitch
private float[]	last_pitch_gain
private float	smooth_gain
private float[]	xx

Constructor Summary

Constructors

Constructor	Description
Filters()	Constructor

Method Summary

Modifier and Type	Method	Description
static void	bw_lpc(float gamma, float[] lpc_in, float[] lpc_out, int order)	bw_lpc
void	comb_filter(float[] exc, int esi, float[] new_exc, int nsi, int nsf, int pitch, float[] pitch_gain, float comb_gain)	Comb Filter
static void	filter_mem2(float[] x, int xs, float[] num, float[] den, float[] y, int ys, int N, int ord, float[] mem, int ms)	filter_mem2
static void	filter_mem2(float[] x, int xs, float[] num, float[] den, int N, int ord, float[] mem, int ms)	filter_mem2
void	fir_mem_up(float[] x, float[] a, float[] y, int N, int M, float[] mem)	fir_mem_up
static void	fir_mem2(float[] x, int xs, float[] num, float[] y, int ys, int N, int ord, float[] mem)	fir_mem2
static void	iir_mem2(float[] x, int xs, float[] den, float[] y, int ys, int N, int ord, float[] mem)	iir_mem2
void	init()	Initialisation
static void	qmf_decomp(float[] xx, float[] aa, float[] y1, float[] y2, int N, int M, float[] mem)	Quadrature Mirror Filter to Split the band in two.
static void	residue_percep_zero(float[] xx, int xxs, float[] ak, float[] awk1, float[] awk2, float[] y, int N, int ord)	residue_percep_zero
static void	syn_percep_zero(float[] xx, int xxs, float[] ak, float[] awk1, float[] awk2, float[] y, int N, int ord)	syn_percep_zero

Methods inherited from class java.lang.Object

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

Field Detail

last_pitch

private int last_pitch

last_pitch_gain

private float[] last_pitch_gain

smooth_gain

private float smooth_gain

xx

private float[] xx

Constructor Detail

Filters

public Filters()

Constructor

Method Detail

init

public void init()

Initialisation

bw_lpc

public static final void bw_lpc(float gamma,
                                float[] lpc_in,
                                float[] lpc_out,
                                int order)

bw_lpc

Parameters:

gamma -

lpc_in -

lpc_out -

order -

filter_mem2

public static final void filter_mem2(float[] x,
                                     int xs,
                                     float[] num,
                                     float[] den,
                                     int N,
                                     int ord,
                                     float[] mem,
                                     int ms)

filter_mem2

Parameters:

x -

xs -

num -

den -

N -

ord -

mem -

ms -

filter_mem2

public static final void filter_mem2(float[] x,
                                     int xs,
                                     float[] num,
                                     float[] den,
                                     float[] y,
                                     int ys,
                                     int N,
                                     int ord,
                                     float[] mem,
                                     int ms)

filter_mem2

Parameters:

x -

xs -

num -

den -

y -

ys -

N -

ord -

mem -

ms -

iir_mem2

public static final void iir_mem2(float[] x,
                                  int xs,
                                  float[] den,
                                  float[] y,
                                  int ys,
                                  int N,
                                  int ord,
                                  float[] mem)

iir_mem2

Parameters:

x -

xs -

den -

y -

ys -

N -

ord -

mem -

fir_mem2

public static final void fir_mem2(float[] x,
                                  int xs,
                                  float[] num,
                                  float[] y,
                                  int ys,
                                  int N,
                                  int ord,
                                  float[] mem)

fir_mem2

Parameters:

x -

xs -

num -

y -

ys -

N -

ord -

mem -

syn_percep_zero

public static final void syn_percep_zero(float[] xx,
                                         int xxs,
                                         float[] ak,
                                         float[] awk1,
                                         float[] awk2,
                                         float[] y,
                                         int N,
                                         int ord)

syn_percep_zero

Parameters:

xx -

xxs -

ak -

awk1 -

awk2 -

y -

N -

ord -

residue_percep_zero

public static final void residue_percep_zero(float[] xx,
                                             int xxs,
                                             float[] ak,
                                             float[] awk1,
                                             float[] awk2,
                                             float[] y,
                                             int N,
                                             int ord)

residue_percep_zero

Parameters:

xx -

xxs -

ak -

awk1 -

awk2 -

y -

N -

ord -

fir_mem_up

public void fir_mem_up(float[] x,
                       float[] a,
                       float[] y,
                       int N,
                       int M,
                       float[] mem)

fir_mem_up

Parameters:

x -

a -

y -

N -

M -

mem -

comb_filter

public void comb_filter(float[] exc,
                        int esi,
                        float[] new_exc,
                        int nsi,
                        int nsf,
                        int pitch,
                        float[] pitch_gain,
                        float comb_gain)

Comb Filter

Parameters:

exc - - decoded excitation

esi -

new_exc - - enhanced excitation

nsi -

nsf - - sub-frame size

pitch - - pitch period

pitch_gain - - pitch gain (3-tap)

comb_gain - - gain of comb filter

qmf_decomp

public static final void qmf_decomp(float[] xx,
                                    float[] aa,
                                    float[] y1,
                                    float[] y2,
                                    int N,
                                    int M,
                                    float[] mem)

Quadrature Mirror Filter to Split the band in two. A 16kHz signal is thus divided into two 8kHz signals representing the low and high bands. (used by wideband encoder)

Parameters:

xx -

aa -

y1 -

y2 -

N -

M -

mem -