org.xiph.speex

Class Ltp

Known Direct Subclasses:
Ltp3Tap, LtpForcedPitch

public abstract class Ltp
extends java.lang.Object

Abstract class that is the base for the various LTP (Long Term Prediction) Quantisation and Unquantisation methods.
Version:
$Revision: 1.2 $
Authors:
Jim Lawrence, helloNetwork.com
Marc Gimpel, Wimba S.A. (mgimpel@horizonwimba.com)

Method Summary

protected static float
inner_prod(float[] x, int xs, float[] y, int ys, int len)
Calculates the inner product of the given vectors.
protected static void
open_loop_nbest_pitch(float[] sw, int swIdx, int start, int end, int len, int[] pitch, float[] gain, int N)
Find the n-best pitch in Open Loop.
abstract int
quant(float[] target, float[] sw, int sws, float[] ak, float[] awk1, float[] awk2, float[] exc, int es, int start, int end, float pitch_coef, int p, int nsf, Bits bits, float[] exc2, int e2s, float[] r, int complexity)
Long Term Prediction Quantification.
abstract int
unquant(float[] exc, int es, int start, float pitch_coef, int nsf, float[] gain_val, Bits bits, int count_lost, int subframe_offset, float last_pitch_gain)
Long Term Prediction Unquantification.

Method Details

inner_prod

protected static float inner_prod(float[] x,
                                  int xs,
                                  float[] y,
                                  int ys,
                                  int len)
Calculates the inner product of the given vectors.
Parameters:
x - - first vector.
xs - - offset of the first vector.
y - - second vector.
ys - - offset of the second vector.
len - - length of the vectors.
Returns:
the inner product of the given vectors.

open_loop_nbest_pitch

protected static void open_loop_nbest_pitch(float[] sw,
                                            int swIdx,
                                            int start,
                                            int end,
                                            int len,
                                            int[] pitch,
                                            float[] gain,
                                            int N)
Find the n-best pitch in Open Loop.
Parameters:
sw -
swIdx -
start -
end -
len -
pitch -
gain -
N -

quant

public abstract int quant(float[] target,
                          float[] sw,
                          int sws,
                          float[] ak,
                          float[] awk1,
                          float[] awk2,
                          float[] exc,
                          int es,
                          int start,
                          int end,
                          float pitch_coef,
                          int p,
                          int nsf,
                          Bits bits,
                          float[] exc2,
                          int e2s,
                          float[] r,
                          int complexity)
Long Term Prediction Quantification.
Returns:
pitch

unquant

public abstract int unquant(float[] exc,
                            int es,
                            int start,
                            float pitch_coef,
                            int nsf,
                            float[] gain_val,
                            Bits bits,
                            int count_lost,
                            int subframe_offset,
                            float last_pitch_gain)
Long Term Prediction Unquantification.
Parameters:
exc - - Excitation
es - - Excitation offset
start - - Smallest pitch value allowed
pitch_coef - - Voicing (pitch) coefficient
nsf - - Number of samples in subframe
gain_val -
bits - - Speex bits buffer.
count_lost -
subframe_offset -
last_pitch_gain -
Returns:
pitch

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