floor0.c (6643B)
1 /******************************************************************** 2 * * 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. * 7 * * 8 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2002 * 9 * by the XIPHOPHORUS Company http://www.xiph.org/ * 10 * * 11 ******************************************************************** 12 13 function: floor backend 0 implementation 14 last mod: $Id: floor0.c 1919 2005-07-24 14:18:04Z baford $ 15 16 ********************************************************************/ 17 18 #include <stdlib.h> 19 #include <string.h> 20 #include <math.h> 21 #include <ogg/ogg.h> 22 #include "vorbis/codec.h" 23 #include "codec_internal.h" 24 #include "registry.h" 25 #include "lpc.h" 26 #include "lsp.h" 27 #include "codebook.h" 28 #include "scales.h" 29 #include "misc.h" 30 #include "os.h" 31 32 #include "misc.h" 33 #include <stdio.h> 34 35 typedef struct { 36 int ln; 37 int m; 38 int **linearmap; 39 int n[2]; 40 41 vorbis_info_floor0 *vi; 42 43 long bits; 44 long frames; 45 } vorbis_look_floor0; 46 47 48 /***********************************************/ 49 50 static void floor0_free_info(vorbis_info_floor *i){ 51 vorbis_info_floor0 *info=(vorbis_info_floor0 *)i; 52 if(info){ 53 memset(info,0,sizeof(*info)); 54 _ogg_free(info); 55 } 56 } 57 58 static void floor0_free_look(vorbis_look_floor *i){ 59 vorbis_look_floor0 *look=(vorbis_look_floor0 *)i; 60 if(look){ 61 62 if(look->linearmap){ 63 64 if(look->linearmap[0])_ogg_free(look->linearmap[0]); 65 if(look->linearmap[1])_ogg_free(look->linearmap[1]); 66 67 _ogg_free(look->linearmap); 68 } 69 memset(look,0,sizeof(*look)); 70 _ogg_free(look); 71 } 72 } 73 74 static vorbis_info_floor *floor0_unpack (vorbis_info *vi,oggpack_buffer *opb){ 75 codec_setup_info *ci=vi->codec_setup; 76 int j; 77 78 vorbis_info_floor0 *info=_ogg_malloc(sizeof(*info)); 79 info->order=oggpack_read(opb,8); 80 info->rate=oggpack_read(opb,16); 81 info->barkmap=oggpack_read(opb,16); 82 info->ampbits=oggpack_read(opb,6); 83 info->ampdB=oggpack_read(opb,8); 84 info->numbooks=oggpack_read(opb,4)+1; 85 86 if(info->order<1)goto err_out; 87 if(info->rate<1)goto err_out; 88 if(info->barkmap<1)goto err_out; 89 if(info->numbooks<1)goto err_out; 90 91 for(j=0;j<info->numbooks;j++){ 92 info->books[j]=oggpack_read(opb,8); 93 if(info->books[j]<0 || info->books[j]>=ci->books)goto err_out; 94 } 95 return(info); 96 97 err_out: 98 floor0_free_info(info); 99 return(NULL); 100 } 101 102 /* initialize Bark scale and normalization lookups. We could do this 103 with static tables, but Vorbis allows a number of possible 104 combinations, so it's best to do it computationally. 105 106 The below is authoritative in terms of defining scale mapping. 107 Note that the scale depends on the sampling rate as well as the 108 linear block and mapping sizes */ 109 110 static void floor0_map_lazy_init(vorbis_block *vb, 111 vorbis_info_floor *infoX, 112 vorbis_look_floor0 *look){ 113 if(!look->linearmap[vb->W]){ 114 vorbis_dsp_state *vd=vb->vd; 115 vorbis_info *vi=vd->vi; 116 codec_setup_info *ci=vi->codec_setup; 117 vorbis_info_floor0 *info=(vorbis_info_floor0 *)infoX; 118 int W=vb->W; 119 int n=ci->blocksizes[W]/2,j; 120 121 /* we choose a scaling constant so that: 122 floor(bark(rate/2-1)*C)=mapped-1 123 floor(bark(rate/2)*C)=mapped */ 124 float scale=look->ln/toBARK(info->rate/2.f); 125 126 /* the mapping from a linear scale to a smaller bark scale is 127 straightforward. We do *not* make sure that the linear mapping 128 does not skip bark-scale bins; the decoder simply skips them and 129 the encoder may do what it wishes in filling them. They're 130 necessary in some mapping combinations to keep the scale spacing 131 accurate */ 132 look->linearmap[W]=_ogg_malloc((n+1)*sizeof(**look->linearmap)); 133 for(j=0;j<n;j++){ 134 int val=floor( toBARK((info->rate/2.f)/n*j) 135 *scale); /* bark numbers represent band edges */ 136 if(val>=look->ln)val=look->ln-1; /* guard against the approximation */ 137 look->linearmap[W][j]=val; 138 } 139 look->linearmap[W][j]=-1; 140 look->n[W]=n; 141 } 142 } 143 144 static vorbis_look_floor *floor0_look(vorbis_dsp_state *vd, 145 vorbis_info_floor *i){ 146 vorbis_info_floor0 *info=(vorbis_info_floor0 *)i; 147 vorbis_look_floor0 *look=_ogg_calloc(1,sizeof(*look)); 148 look->m=info->order; 149 look->ln=info->barkmap; 150 look->vi=info; 151 152 look->linearmap=_ogg_calloc(2,sizeof(*look->linearmap)); 153 154 return look; 155 } 156 157 static void *floor0_inverse1(vorbis_block *vb,vorbis_look_floor *i){ 158 vorbis_look_floor0 *look=(vorbis_look_floor0 *)i; 159 vorbis_info_floor0 *info=look->vi; 160 int j,k; 161 162 int ampraw=oggpack_read(&vb->opb,info->ampbits); 163 if(ampraw>0){ /* also handles the -1 out of data case */ 164 long maxval=(1<<info->ampbits)-1; 165 float amp=(float)ampraw/maxval*info->ampdB; 166 int booknum=oggpack_read(&vb->opb,_ilog(info->numbooks)); 167 168 if(booknum!=-1 && booknum<info->numbooks){ /* be paranoid */ 169 codec_setup_info *ci=vb->vd->vi->codec_setup; 170 codebook *b=ci->fullbooks+info->books[booknum]; 171 float last=0.f; 172 173 /* the additional b->dim is a guard against any possible stack 174 smash; b->dim is provably more than we can overflow the 175 vector */ 176 float *lsp=_vorbis_block_alloc(vb,sizeof(*lsp)*(look->m+b->dim+1)); 177 178 for(j=0;j<look->m;j+=b->dim) 179 if(vorbis_book_decodev_set(b,lsp+j,&vb->opb,b->dim)==-1)goto eop; 180 for(j=0;j<look->m;){ 181 for(k=0;k<b->dim;k++,j++)lsp[j]+=last; 182 last=lsp[j-1]; 183 } 184 185 lsp[look->m]=amp; 186 return(lsp); 187 } 188 } 189 eop: 190 return(NULL); 191 } 192 193 static int floor0_inverse2(vorbis_block *vb,vorbis_look_floor *i, 194 void *memo,float *out){ 195 vorbis_look_floor0 *look=(vorbis_look_floor0 *)i; 196 vorbis_info_floor0 *info=look->vi; 197 198 floor0_map_lazy_init(vb,info,look); 199 200 if(memo){ 201 float *lsp=(float *)memo; 202 float amp=lsp[look->m]; 203 204 /* take the coefficients back to a spectral envelope curve */ 205 vorbis_lsp_to_curve(out, 206 look->linearmap[vb->W], 207 look->n[vb->W], 208 look->ln, 209 lsp,look->m,amp,(float)info->ampdB); 210 return(1); 211 } 212 memset(out,0,sizeof(*out)*look->n[vb->W]); 213 return(0); 214 } 215 216 /* export hooks */ 217 vorbis_func_floor floor0_exportbundle={ 218 NULL,&floor0_unpack,&floor0_look,&floor0_free_info, 219 &floor0_free_look,&floor0_inverse1,&floor0_inverse2 220 }; 221 222 223