Package org.xiph.speex
Class Lpc
java.lang.Object
org.xiph.speex.Lpc
LPC - and Reflection Coefficients.
The next two functions calculate linear prediction coefficients and/or the related reflection coefficients from the first P_MAX+1 values of the autocorrelation function.
Invented by N. Levinson in 1947, modified by J. Durbin in 1959.
- Version:
- $Revision: 1.2 $
- Author:
- Marc Gimpel, Wimba S.A. (mgimpel@horizonwimba.com)
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionstatic void
autocorr
(float[] x, float[] ac, int lag, int n) Compute the autocorrelation ,--, ac(i) = > x(n) * x(n-i) for all n `--' for lags between 0 and lag-1, and x == 0 outside 0...n-1static float
wld
(float[] lpc, float[] ac, float[] ref, int p) Returns minimum mean square error.
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Constructor Details
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Lpc
public Lpc()
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Method Details
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wld
public static float wld(float[] lpc, float[] ac, float[] ref, int p) Returns minimum mean square error.- Parameters:
lpc
- - float[0...p-1] LPC coefficientsac
- - in: float[0...p] autocorrelation valuesref
- - out: float[0...p-1] reflection coef'sp
-- Returns:
- minimum mean square error.
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autocorr
public static void autocorr(float[] x, float[] ac, int lag, int n) Compute the autocorrelation ,--, ac(i) = > x(n) * x(n-i) for all n `--' for lags between 0 and lag-1, and x == 0 outside 0...n-1- Parameters:
x
- - in: float[0...n-1] samples xac
- - out: float[0...lag-1] ac valueslag
-n
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