org.xiph.speex

Class Filters


public class Filters
extends java.lang.Object

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

Field Summary

private int
last_pitch
private float[]
last_pitch_gain
private float
smooth_gain
private float[]
xx

Constructor Summary

Filters()
Constructor

Method Summary

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
static void
fir_mem2(float[] x, int xs, float[] num, float[] y, int ys, int N, int ord, float[] mem)
fir_mem2
void
fir_mem_up(float[] x, float[] a, float[] y, int N, int M, float[] mem)
fir_mem_up
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

Field Details

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 Details

Filters

public Filters()
Constructor

Method Details

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 -

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

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 -

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 -

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 -

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 -

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 -

init

public void init()
Initialisation

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 -

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 -

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 -

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