ocvolume.dsp
Class endPt

java.lang.Object
  |
  +--ocvolume.dsp.endPt

public class endPt

extends java.lang.Object

last modified: June 15, 2002
description: this is the detection of the noise and search for the spot where the acutal word is being sounded, and remove the noise from the sample.
calls: none
called by: volume, train
input: speech signal
output: modified speech signal

Constructor Summary

endPt()

Method Summary

static short[]	absCut(short[] sample) a method to use this class calls: zeroCrossingBoolean, avgEnergy, zeroCrossing, chopping called by: volume
static int[]	avgEnergy(short[] sample) 5ms frame (80 samples / frame) determent the noise location base on the energy calls: none called by: absCut
static short[]	chopping(short[] sample, int[] cut) cut the sample into smaller part calls: none called by: absCut
static int[]	zeroCrossing(short[] sample, int[] energy, boolean[] crossing) search for the end points based on zero-crossing and result from avgEnergy calls: none called by: absCut
static boolean[]	zeroCrossingBoolean(short[] sample) Simply mark off the location of Zero-Crossing calls: none called by: absCut

Methods inherited from class java.lang.Object

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

Constructor Detail

endPt

public endPt()

Method Detail

absCut

public static short[] absCut(short[] sample)

a method to use this class
calls: zeroCrossingBoolean, avgEnergy, zeroCrossing, chopping
called by: volume

Parameters:

sample - the sample that's going to be modified

Returns:

modified sample

chopping

public static short[] chopping(short[] sample,
                               int[] cut)

cut the sample into smaller part
calls: none
called by: absCut

Parameters:

sample - the sample that's going to be chopped

cut - the location that were returned from zeroCrossing or avgEnergy

Returns:

the cut sample

avgEnergy

public static int[] avgEnergy(short[] sample)

5ms frame (80 samples / frame)
determent the noise location base on the energy
calls: none
called by: absCut

Parameters:

sample - the sample which is being analyze

Returns:

squared mean energy

zeroCrossingBoolean

public static boolean[] zeroCrossingBoolean(short[] sample)

Simply mark off the location of Zero-Crossing
calls: none
called by: absCut

Parameters:

sample - speech signal

Returns:

a boolean array with the same size as the sample, true = a zero-crossing, false = no zero-crossing

zeroCrossing

public static int[] zeroCrossing(short[] sample,
                                 int[] energy,
                                 boolean[] crossing)

search for the end points based on zero-crossing and result from avgEnergy
calls: none
called by: absCut

Parameters:

sample - speech signal

energy - result from avgEnergy, which is used as the starting point

crossing - result from zeroCrossingBoolean

Returns:

start and end of voiced speech signal