net.java.sip.communicator.impl.neomedia.codec.audio.g729
Class PreProc

java.lang.Object
  net.java.sip.communicator.impl.neomedia.codec.audio.g729.PreProc

 class PreProc
extends Object

Preprocessing of input speech. - 2nd order high pass filter with cut off frequency at 140 Hz. 2nd order high pass filter with cut off frequency at 140 Hz. Designed with SPPACK efi command -40 dB att, 0.25 ri. Algorithm:

  y[i] = b[0]*x[i] + b[1]*x[i-1] + b[2]*x[i-2]
                   + a[1]*y[i-1] + a[2]*y[i-2];

     b[3] = {0.92727435E+00, -0.18544941E+01, 0.92727435E+00};
     a[3] = {0.10000000E+01, 0.19059465E+01, -0.91140240E+00};
 

Author:

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

Constructor Summary

PreProc()

Method Summary

(package private) void	init_pre_process() Init Pre Process
(package private) void	pre_process(float[] signal, int signal_offset, int lg) Pre Process

Methods inherited from class java.lang.Object

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

Constructor Detail

PreProc

PreProc()

Method Detail

init_pre_process

void init_pre_process()

Init Pre Process

pre_process

void pre_process(float[] signal,
                 int signal_offset,
                 int lg)

Pre Process

Parameters:

signal - (i/o) : signal

signal_offset - (input) : signal offset

lg - (i) : length of signal