1 /********************************************************************
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. *
8 * THE OggSQUISH SOURCE CODE IS (C) COPYRIGHT 1994-1999 *
9 * by 1999 Monty <monty@xiph.org> and The XIPHOPHORUS Company *
10 * http://www.xiph.org/ *
12 ********************************************************************
14 function: PCM data envelope analysis and manipulation
15 author: Monty <xiphmont@mit.edu>
16 modifications by: Monty
17 last modification date: Oct 22 1999
21 ********************************************************************/
35 void _ve_envelope_init(envelope_lookup *e,int samples_per){
38 e->winlen=samples_per;
39 e->window=malloc(e->winlen*sizeof(double));
40 mdct_init(&e->mdct,e->winlen);
42 /* We just use a straight sin(x) window for this */
43 for(i=0;i<e->winlen;i++)
44 e->window[i]=sin((i+.5)/e->winlen*M_PI);
48 void _ve_envelope_clear(envelope_lookup *e){
49 if(e->window)free(e->window);
51 memset(e,0,sizeof(envelope_lookup));
54 /* use MDCT for spectral power estimation */
56 static void _ve_deltas(double *deltas,double *pcm,int n,double *window,
57 int winsize,mdct_lookup *m){
59 double *out=alloca(sizeof(double)*winsize/2);
64 mdct_forward(m,pcm+j*winsize,out,window);
65 for(i=winsize/10;i<winsize/2;i++)
67 if(deltas[j]<acc)deltas[j]=acc;
71 void _ve_envelope_deltas(vorbis_dsp_state *v){
72 vorbis_info *vi=v->vi;
73 int step=vi->envelopesa;
75 int dtotal=v->pcm_current/vi->envelopesa;
76 int dcurr=v->envelope_current;
80 double *mult=v->multipliers+dcurr;
81 memset(mult,0,sizeof(double)*(dtotal-dcurr));
83 for(pch=0;pch<vi->channels;pch++){
84 double *pcm=v->pcm[pch]+dcurr*step;
85 _ve_deltas(mult,pcm,dtotal-dcurr,v->ve.window,v->ve.winlen,&v->ve.mdct);
87 v->envelope_current=dtotal;
96 sprintf(buffer,"delt%d.m",frameno);
97 out=fopen(buffer,"w+");
98 for(j=0;j<v->envelope_current;j++)
99 fprintf(out,"%d %g\n",j*vi->envelopesa+vi->envelopesa/2,v->multipliers[j]);
102 sprintf(buffer,"deltpcm%d.m",frameno++);
103 out=fopen(buffer,"w+");
104 for(k=0;k<vi->channels;k++){
105 for(j=0;j<v->pcm_current;j++)
106 fprintf(out,"%d %g\n",j,v->pcm[k][j]);