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Update libvorbis to 1.3.3.

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This commit is contained in:
lllucius
2013-10-24 18:24:47 +00:00
parent 78309687be
commit 3a33e2f717
374 changed files with 119632 additions and 45432 deletions
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51
lib-src/libvorbis/lib/lpc.c
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@@ -5,13 +5,13 @@
* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
* *
* THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2007 *
* THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009 *
* by the Xiph.Org Foundation http://www.xiph.org/ *
* *
********************************************************************
function: LPC low level routines
last mod: $Id: lpc.c,v 1.8 2008-02-02 15:53:53 richardash1981 Exp $
last mod: $Id: lpc.c 16227 2009-07-08 06:58:46Z xiphmont $
********************************************************************/
@@ -62,6 +62,7 @@ float vorbis_lpc_from_data(float *data,float *lpci,int n,int m){
double *aut=alloca(sizeof(*aut)*(m+1));
double *lpc=alloca(sizeof(*lpc)*(m));
double error;
double epsilon;
int i,j;
/* autocorrelation, p+1 lag coefficients */
@@ -71,17 +72,19 @@ float vorbis_lpc_from_data(float *data,float *lpci,int n,int m){
for(i=j;i<n;i++)d+=(double)data[i]*data[i-j];
aut[j]=d;
}
/* Generate lpc coefficients from autocorr values */
error=aut[0];
/* set our noise floor to about -100dB */
error=aut[0] * (1. + 1e-10);
epsilon=1e-9*aut[0]+1e-10;
for(i=0;i<m;i++){
double r= -aut[i+1];
if(error==0){
memset(lpci,0,m*sizeof(*lpci));
return 0;
if(error<epsilon){
memset(lpc+i,0,(m-i)*sizeof(*lpc));
goto done;
}
/* Sum up this iteration's reflection coefficient; note that in
@@ -90,10 +93,10 @@ float vorbis_lpc_from_data(float *data,float *lpci,int n,int m){
each iteration. */
for(j=0;j<i;j++)r-=lpc[j]*aut[i-j];
r/=error;
r/=error;
/* Update LPC coefficients and total error */
lpc[i]=r;
for(j=0;j<i/2;j++){
double tmp=lpc[j];
@@ -101,23 +104,36 @@ float vorbis_lpc_from_data(float *data,float *lpci,int n,int m){
lpc[j]+=r*lpc[i-1-j];
lpc[i-1-j]+=r*tmp;
}
if(i%2)lpc[j]+=lpc[j]*r;
if(i&1)lpc[j]+=lpc[j]*r;
error*=1.f-r*r;
error*=1.-r*r;
}
done:
/* slightly damp the filter */
{
double g = .99;
double damp = g;
for(j=0;j<m;j++){
lpc[j]*=damp;
damp*=g;
}
}
for(j=0;j<m;j++)lpci[j]=(float)lpc[j];
/* we need the error value to know how big an impulse to hit the
filter with later */
return error;
}
void vorbis_lpc_predict(float *coeff,float *prime,int m,
float *data,long n){
/* in: coeff[0...m-1] LPC coefficients
/* in: coeff[0...m-1] LPC coefficients
prime[0...m-1] initial values (allocated size of n+m-1)
out: data[0...n-1] data samples */
@@ -138,12 +154,7 @@ void vorbis_lpc_predict(float *coeff,float *prime,int m,
p=m;
for(j=0;j<m;j++)
y-=work[o++]*coeff[--p];
data[i]=work[o]=y;
}
}