lib/envelope.c

   1 /********************************************************************
   2  *                                                                  *
   3  * THIS FILE IS PART OF THE Ogg Vorbis SOFTWARE CODEC SOURCE CODE.  *
   4  * USE, DISTRIBUTION AND REPRODUCTION OF THIS SOURCE IS GOVERNED BY *
   5  * THE GNU PUBLIC LICENSE 2, WHICH IS INCLUDED WITH THIS SOURCE.    *
   6  * PLEASE READ THESE TERMS DISTRIBUTING.                            *
   7  *                                                                  *
   8  * THE OggSQUISH SOURCE CODE IS (C) COPYRIGHT 1994-2000             *
   9  * by Monty <monty@xiph.org> and The XIPHOPHORUS Company            *
  10  * http://www.xiph.org/                                             *
  11  *                                                                  *
  12  ********************************************************************
  13
  14  function: PCM data envelope analysis and manipulation
  15  last mod: $Id: envelope.c,v 1.16 2000/03/10 13:21:18 xiphmont Exp $
  16
  17  Preecho calculation.
  18
  19  ********************************************************************/
  20
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <stdio.h>
  24 #include <math.h>
  25 #include "vorbis/codec.h"
  26
  27 #include "os.h"
  28 #include "mdct.h"
  29 #include "envelope.h"
  30 #include "bitwise.h"
  31 #include "window.h"
  32 #include "misc.h"
  33
  34 void _ve_envelope_init(envelope_lookup *e,int samples_per){
  35   int i;
  36
  37   e->winlen=samples_per;
  38   e->window=malloc(e->winlen*sizeof(double));
  39   mdct_init(&e->mdct,e->winlen);
  40
  41   /* We just use a straight sin(x) window for this */
  42   for(i=0;i<e->winlen;i++)
  43     e->window[i]=sin((i+.5)/e->winlen*M_PI);
  44
  45 }
  46
  47 void _ve_envelope_clear(envelope_lookup *e){
  48   if(e->window)free(e->window);
  49   mdct_clear(&e->mdct);
  50   memset(e,0,sizeof(envelope_lookup));
  51 }
  52
  53 /* use MDCT for spectral power estimation */
  54
  55 static void _ve_deltas(double *deltas,double *pcm,int n,double *window,
  56                        int winsize,mdct_lookup *m){
  57   int i,j;
  58   double *out=alloca(sizeof(double)*winsize);
  59
  60   for(j=0;j<n;j++){
  61     double acc=0.;
  62
  63     memcpy(out,pcm+j*winsize,winsize*sizeof(double));
  64     for(i=0;i<winsize;i++)
  65       out[i]*=window[i];
  66
  67     mdct_forward(m,out,out);
  68
  69     for(i=winsize/10;i<winsize/2;i++)
  70       acc+=fabs(out[i]);
  71     if(deltas[j]<acc)deltas[j]=acc;
  72   }
  73 }
  74
  75 void _ve_envelope_deltas(vorbis_dsp_state *v){
  76   vorbis_info *vi=v->vi;
  77   int step=vi->envelopesa;
  78
  79   int dtotal=v->pcm_current/vi->envelopesa;
  80   int dcurr=v->envelope_current;
  81   int pch;
  82
  83   if(dtotal>dcurr){
  84     double *mult=v->multipliers+dcurr;
  85     memset(mult,0,sizeof(double)*(dtotal-dcurr));
  86
  87     for(pch=0;pch<vi->channels;pch++){
  88       double *pcm=v->pcm[pch]+dcurr*step;
  89       _ve_deltas(mult,pcm,dtotal-dcurr,v->ve.window,v->ve.winlen,&v->ve.mdct);
  90     }
  91     v->envelope_current=dtotal;
  92
  93 #ifdef ANALYSIS
  94     {
  95       static int frameno=0;
  96       FILE *out;
  97       char buffer[80];
  98       int j,k;
  99
 100       sprintf(buffer,"delt%d.m",frameno);
 101       out=fopen(buffer,"w+");
 102       for(j=0;j<v->envelope_current;j++)
 103         fprintf(out,"%d %g\n",j*vi->envelopesa+vi->envelopesa/2,v->multipliers[j]);
 104       fclose(out);
 105
 106       sprintf(buffer,"deltpcm%d.m",frameno++);
 107       out=fopen(buffer,"w+");
 108       for(k=0;k<vi->channels;k++){
 109         for(j=0;j<v->pcm_current;j++)
 110           fprintf(out,"%d %g\n",j,v->pcm[k][j]);
 111         fprintf(out,"\n");
 112       }
 113       fclose(out);
 114     }
 115 #endif
 116
 117   }
 118 }
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