1 /********************************************************************
3 * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
4 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
5 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
6 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
8 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2001 *
9 * by the Xiph.Org Foundation http://www.xiph.org/ *
11 ********************************************************************
13 function: metrics and quantization code for LSP VQ codebooks
16 ********************************************************************/
25 char *vqext_booktype="LSPdata";
26 quant_meta q={0,0,0,1}; /* set sequence data */
29 float global_maxdel=M_PI;
30 float global_mindel=M_PI;
32 void vqext_quantize(vqgen *v,quant_meta *q){
34 float maxquant=((1<<q->quant)-1);
37 /* first find the basic delta amount from the maximum span to be
38 encoded. Loosen the delta slightly to allow for additional error
39 during sequence quantization */
41 delta=(global_maxdel-global_mindel)/((1<<q->quant)-1.5f);
43 q->min=_float32_pack(global_mindel);
44 q->delta=_float32_pack(delta);
46 mindel=_float32_unpack(q->min);
47 delta=_float32_unpack(q->delta);
49 for(j=0;j<v->entries;j++){
51 for(k=0;k<v->elements;k++){
52 float val=_now(v,j)[k];
53 float now=rint((val-last-mindel)/delta);
57 /* be paranoid; this should be impossible */
58 fprintf(stderr,"fault; quantized value<0\n");
63 /* be paranoid; this should be impossible */
64 fprintf(stderr,"fault; quantized value>max\n");
67 last=(now*delta)+mindel+last;
73 void vqext_quantize(vqgen *v,quant_meta *q){
80 /* LSP training metric. We weight error proportional to distance
81 *between* LSP vector values. The idea of this metric is not to set
82 final cells, but get the midpoint spacing into a form conducive to
83 what we want, which is weighting toward preserving narrower
86 #define FUDGE (global_maxdel-weight[i])
88 float *vqext_weight(vqgen *v,float *p){
93 float predist=(p[i]-lastp);
94 float postdist=(p[i+1]-p[i]);
95 weight[i]=(predist<postdist?predist:postdist);
102 float *vqext_weight(vqgen *v,float *p){
107 /* candidate,actual */
108 float vqext_metric(vqgen *v,float *e, float *p){
113 float val=(p[i]-e[i])*FUDGE;
116 return sqrt(acc/v->elements);
119 /* Data files are line-vectors, now just deltas. The codebook entries
120 want to be monotonically increasing, so we adjust */
122 /* assume vqext_aux==1 */
123 void vqext_addpoint_adj(vqgen *v,float *b,int start,int dim,int cols,int num){
124 float *a=alloca(sizeof(float)*(dim+1)); /* +aux */
129 base=a[i]=b[i+start]+base;
131 if(start+dim+1>cols) /* +aux */
134 a[i]=b[i+start]+base;
136 vqgen_addpoint(v,a,a+dim);
139 /* we just need to calc the global_maxdel from the training set */
140 void vqext_preprocess(vqgen *v){
145 for(j=0;j<v->points;j++){
147 for(k=0;k<v->elements+v->aux;k++){
148 float p=_point(v,j)[k];
149 if(p-last>global_maxdel)global_maxdel=p-last;
150 if(p-last<global_mindel)global_mindel=p-last;
155 weight=_ogg_malloc(sizeof(float)*v->elements);