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 1994-2000 *
9 * by Monty <monty@xiph.org> and The XIPHOPHORUS Company *
10 * http://www.xiph.org/ *
12 ********************************************************************
14 function: floor backend 0 implementation
15 last mod: $Id: floor0.c,v 1.8 2000/02/09 22:04:12 xiphmont Exp $
17 ********************************************************************/
22 #include "vorbis/codec.h"
27 #include "bookinternal.h"
37 vorbis_info_floor0 *vi;
41 static void free_info(vorbis_info_floor *i){
43 memset(i,0,sizeof(vorbis_info_floor0));
48 static void free_look(vorbis_look_floor *i){
49 vorbis_look_floor0 *f=(vorbis_look_floor0 *)i;
51 lpc_clear(&f->lpclook);
52 memset(f,0,sizeof(vorbis_look_floor0));
57 static void pack (vorbis_info_floor *i,oggpack_buffer *opb){
58 vorbis_info_floor0 *d=(vorbis_info_floor0 *)i;
60 _oggpack_write(opb,d->order,8);
61 _oggpack_write(opb,d->rate,16);
62 _oggpack_write(opb,d->barkmap,16);
63 _oggpack_write(opb,d->ampbits,6);
64 _oggpack_write(opb,d->ampdB,8);
65 _oggpack_write(opb,d->stages-1,4);
66 for(j=0;j<d->stages;j++)
67 _oggpack_write(opb,d->books[j],8);
70 static vorbis_info_floor *unpack (vorbis_info *vi,oggpack_buffer *opb){
72 vorbis_info_floor0 *d=malloc(sizeof(vorbis_info_floor0));
73 d->order=_oggpack_read(opb,8);
74 d->rate=_oggpack_read(opb,16);
75 d->barkmap=_oggpack_read(opb,16);
76 d->ampbits=_oggpack_read(opb,6);
77 d->ampdB=_oggpack_read(opb,8);
78 d->stages=_oggpack_read(opb,4)+1;
80 if(d->order<1)goto err_out;
81 if(d->rate<1)goto err_out;
82 if(d->barkmap<1)goto err_out;
83 if(d->stages<1)goto err_out;
85 for(j=0;j<d->stages;j++){
86 d->books[j]=_oggpack_read(opb,8);
87 if(d->books[j]<0 || d->books[j]>=vi->books)goto err_out;
95 static vorbis_look_floor *look (vorbis_info *vi,vorbis_info_mode *mi,
96 vorbis_info_floor *i){
97 vorbis_info_floor0 *d=(vorbis_info_floor0 *)i;
98 vorbis_look_floor0 *ret=malloc(sizeof(vorbis_look_floor0));
100 ret->n=vi->blocksizes[mi->blockflag]/2;
102 lpc_init(&ret->lpclook,ret->n,d->barkmap,d->rate,ret->m);
109 static int forward(vorbis_block *vb,vorbis_look_floor *i,
110 double *in,double *out){
112 vorbis_look_floor0 *look=(vorbis_look_floor0 *)i;
113 vorbis_info_floor0 *info=look->vi;
115 /* use 'out' as temp storage */
116 /* Convert our floor to a set of lpc coefficients */
117 double amp=sqrt(vorbis_curve_to_lpc(in,out,&look->lpclook));
119 /* amp is in the range 0. to 1. (well, more like .7). Log scale it */
122 (1<<ampbits)-1 == amp dB = 1. amp */
124 long ampscale=fromdB(info->ampdB);
125 long maxval=(1<<info->ampbits)-1;
127 long val=todB(amp*ampscale)/info->ampdB*maxval+1;
129 if(val<0)val=0; /* likely */
130 if(val>maxval)val=maxval; /* not bloody likely */
132 _oggpack_write(&vb->opb,val,info->ampbits);
134 amp=fromdB((val-.5)/maxval*info->ampdB)/ampscale;
140 double *work=alloca(sizeof(double)*look->m);
142 /* LSP <-> LPC is orthogonal and LSP quantizes more stably */
143 vorbis_lpc_to_lsp(out,out,look->m);
144 memcpy(work,out,sizeof(double)*look->m);
146 /* code the spectral envelope, and keep track of the actual
147 quantized values; we don't want creeping error as each block is
148 nailed to the last quantized value of the previous block. */
150 /* first stage is a bit different because quantization error must be
152 for(stage=0;stage<info->stages;stage++){
153 codebook *b=vb->vd->fullbooks+info->books[stage];
158 for(k=0;k<b->dim;k++)out[j+k]-=last;
159 vorbis_book_encodev(b,out+j,&vb->opb);
160 for(k=0;k<b->dim;k++,j++){
167 memcpy(out,work,sizeof(double)*look->m);
169 vorbis_book_encodev(b,out+j,&vb->opb);
170 for(k=0;k<b->dim;k++,j++)work[j]-=out[j];
174 /* take the coefficients back to a spectral envelope curve */
175 vorbis_lsp_to_lpc(out,out,look->m);
176 vorbis_lpc_to_curve(out,out,amp,&look->lpclook);
180 memset(out,0,sizeof(double)*look->n);
184 static int inverse(vorbis_block *vb,vorbis_look_floor *i,double *out){
185 vorbis_look_floor0 *look=(vorbis_look_floor0 *)i;
186 vorbis_info_floor0 *info=look->vi;
189 long ampraw=_oggpack_read(&vb->opb,info->ampbits);
191 long ampscale=fromdB(info->ampdB);
192 long maxval=(1<<info->ampbits)-1;
193 double amp=fromdB((ampraw-.5)/maxval*info->ampdB)/ampscale;
195 memset(out,0,sizeof(double)*look->m);
196 for(stage=0;stage<info->stages;stage++){
197 codebook *b=vb->vd->fullbooks+info->books[stage];
198 for(j=0;j<look->m;j+=b->dim)
199 vorbis_book_decodev(b,out+j,&vb->opb);
203 for(k=0;k<b->dim;k++,j++)out[j]+=last;
210 /* take the coefficients back to a spectral envelope curve */
211 vorbis_lsp_to_lpc(out,out,look->m);
212 vorbis_lpc_to_curve(out,out,amp,&look->lpclook);
215 memset(out,0,sizeof(double)*look->n);
220 vorbis_func_floor floor0_exportbundle={
221 &pack,&unpack,&look,&free_info,&free_look,&forward,&inverse