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/********************************************************************
* *
* THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
* 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 1994-2001 *
* by the XIPHOPHORUS Company http://www.xiph.org/ *
********************************************************************
function: PCM data envelope analysis and manipulation
last mod: $Id: envelope.c,v 1.37 2001/08/13 01:36:56 xiphmont Exp $
Preecho calculation.
********************************************************************/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <math.h>
#include <ogg/ogg.h>
#include "vorbis/codec.h"
#include "codec_internal.h"
#include "os.h"
#include "scales.h"
#include "envelope.h"
#include "misc.h"
#include "iir.c" /* Yes, ugly, but needed for inlining */
/* Digital filter designed by mkfilter/mkshape/gencode A.J. Fisher */
static int cheb_highpass_stages=6;
static float cheb_highpass_B[]={1.f,-6.f,15.f,-20.f,15.f,-6.f,1.f};
static int cheb_bandpass_stages=6;
static float cheb_bandpass_B[]={-1.f,0.f,3.f,0.f,-3.f,0.f,1.f};
/* 10kHz Chebyshev highpass */
static float cheb_highpass10k_gain= 54.34519586f;
static float cheb_highpass10k_A[]={
-0.2064797169f,
-0.5609713214f,
-1.1352465327f,
-1.4495555418f,
-1.7938140760f,
-0.9473564683f};
/* 6kHz-10kHz Chebyshev bandpass */
static float cheb_bandpass6k_gain=113.4643935f;
static float cheb_bandpass6k_A[]={
-0.5712621337f,
1.5626130710f,
-3.3348854983f,
4.0471340821f,
-4.0051680331f,
2.2786325610f};
/* 3kHz-6kHz Chebyshev bandpass */
static float cheb_bandpass3k_gain= 248.8359377f;
static float cheb_bandpass3k_A[]={
-0.6564230022f,
3.3747911257f,
-8.0098635981f,
11.0040876874f,
-9.2250963484f,
4.4760355389f};
/* 1.5kHz-3kHz Chebyshev bandpass */
static float cheb_bandpass1k_gain= 1798.537183f;
static float cheb_bandpass1k_A[]={
-0.8097527363f,
4.7725742682f,
-11.9800219408f,
16.3770336223f,
-12.8553129536f,
5.4948074309f};
void _ve_envelope_init(envelope_lookup *e,vorbis_info *vi){
codec_setup_info *ci=vi->codec_setup;
vorbis_info_psy_global *gi=ci->psy_g_param;
int ch=vi->channels;
int window=gi->envelopesa;
int i;
e->winlength=window;
e->minenergy=fromdB(gi->preecho_minenergy);
e->iir=_ogg_calloc(ch*4,sizeof(IIR_state));
e->filtered=_ogg_calloc(ch*4,sizeof(float *));
e->ch=ch;
e->storage=128;
for(i=0;i<ch*4;i+=4){
IIR_init(e->iir+i,cheb_highpass_stages,cheb_highpass10k_gain,
cheb_highpass10k_A,cheb_highpass_B);
IIR_init(e->iir+i+1,cheb_bandpass_stages,cheb_bandpass6k_gain,
cheb_bandpass6k_A,cheb_bandpass_B);
IIR_init(e->iir+i+2,cheb_bandpass_stages,cheb_bandpass3k_gain,
cheb_bandpass3k_A,cheb_bandpass_B);
IIR_init(e->iir+i+3,cheb_bandpass_stages,cheb_bandpass1k_gain,
cheb_bandpass1k_A,cheb_bandpass_B);
e->filtered[i]=_ogg_calloc(e->storage,sizeof(float));
e->filtered[i+1]=_ogg_calloc(e->storage,sizeof(float));
e->filtered[i+2]=_ogg_calloc(e->storage,sizeof(float));
e->filtered[i+3]=_ogg_calloc(e->storage,sizeof(float));
}
}
void _ve_envelope_clear(envelope_lookup *e){
int i;
for(i=0;i<e->ch*4;i++){
IIR_clear((e->iir+i));
_ogg_free(e->filtered[i]);
}
_ogg_free(e->filtered);
_ogg_free(e->iir);
memset(e,0,sizeof(envelope_lookup));
}
/* straight threshhold based until we find something that works better
and isn't patented */
static float _ve_deltai(envelope_lookup *ve,float *pre,float *post){
long n=ve->winlength;
long i;
/* we want to have a 'minimum bar' for energy, else we're just
basing blocks on quantization noise that outweighs the signal
itself (for low power signals) */
float minV=ve->minenergy;
float A=minV*minV*n;
float B=A;
for(i=0;i<n;i++){
A+=pre[i]*pre[i];
B+=post[i]*post[i];
}
A=todB(&A);
B=todB(&B);
return(B-A);
}
long _ve_envelope_search(vorbis_dsp_state *v,long searchpoint){
vorbis_info *vi=v->vi;
codec_setup_info *ci=vi->codec_setup;
vorbis_info_psy_global *gi=ci->psy_g_param;
envelope_lookup *ve=((backend_lookup_state *)(v->backend_state))->ve;
long i,j,k;
/* make sure we have enough storage to match the PCM */
if(v->pcm_storage>ve->storage){
ve->storage=v->pcm_storage;
for(i=0;i<ve->ch*4;i++)
ve->filtered[i]=_ogg_realloc(ve->filtered[i],ve->storage*sizeof(float));
}
/* catch up the highpass to match the pcm */
for(i=0;i<ve->ch;i++){
float *pcm=v->pcm[i];
float *filtered0=ve->filtered[i*4];
float *filtered1=ve->filtered[i*4+1];
float *filtered2=ve->filtered[i*4+2];
float *filtered3=ve->filtered[i*4+3];
IIR_state *iir0=ve->iir+i*4;
IIR_state *iir1=ve->iir+i*4+1;
IIR_state *iir2=ve->iir+i*4+2;
IIR_state *iir3=ve->iir+i*4+3;
int flag=1;
for(j=ve->current;j<v->pcm_current;j++){
filtered0[j]=IIR_filter(iir0,pcm[j]);
filtered1[j]=IIR_filter_Band(iir1,pcm[j]);
filtered2[j]=IIR_filter_Band(iir2,pcm[j]);
filtered3[j]=IIR_filter_Band(iir3,pcm[j]);
if(pcm[j])flag=0;
}
if(flag && ve->current+64<v->pcm_current){
IIR_reset(iir0);
IIR_reset(iir1);
IIR_reset(iir2);
IIR_reset(iir3);
}
}
ve->current=v->pcm_current;
/* Now search through our cached highpass data for breaking points */
/* starting point */
if(v->W)
j=v->centerW+ci->blocksizes[1]/4-ci->blocksizes[0]/4;
else
j=v->centerW;
if(j<ve->lastmark)j=ve->lastmark;
while(j+ve->winlength<=v->pcm_current){
if(j>=searchpoint)return(1);
ve->lastmark=j;
for(i=0;i<ve->ch;i++){
for(k=0;k<4;k++){
float *filtered=ve->filtered[i*4+k]+j;
float m=_ve_deltai(ve,filtered-ve->winlength,filtered);
if(m>gi->preecho_thresh[k])return(0);
if(m<gi->postecho_thresh[k])return(0);
}
}
j+=min(ci->blocksizes[0],ve->winlength)/2;
}
if(j>=searchpoint)return(1);
return(-1);
}
void _ve_envelope_shift(envelope_lookup *e,long shift){
int i;
for(i=0;i<e->ch*4;i++)
memmove(e->filtered[i],e->filtered[i]+shift,(e->current-shift)*
sizeof(float));
e->current-=shift;
e->lastmark-=shift;
}
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