lib/mapping0.c

   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 1994-2001             *
   9  * by the XIPHOPHORUS Company http://www.xiph.org/                  *
  10  *                                                                  *
  11  ********************************************************************
  12
  13  function: channel mapping 0 implementation
  14  last mod: $Id: mapping0.c,v 1.35 2001/08/13 11:33:39 xiphmont Exp $
  15
  16  ********************************************************************/
  17
  18 #include <stdlib.h>
  19 #include <stdio.h>
  20 #include <string.h>
  21 #include <math.h>
  22 #include <ogg/ogg.h>
  23 #include "vorbis/codec.h"
  24 #include "codec_internal.h"
  25 #include "codebook.h"
  26 #include "bitbuffer.h"
  27 #include "registry.h"
  28 #include "psy.h"
  29 #include "misc.h"
  30
  31 /* simplistic, wasteful way of doing this (unique lookup for each
  32    mode/submapping); there should be a central repository for
  33    identical lookups.  That will require minor work, so I'm putting it
  34    off as low priority.
  35
  36    Why a lookup for each backend in a given mode?  Because the
  37    blocksize is set by the mode, and low backend lookups may require
  38    parameters from other areas of the mode/mapping */
  39
  40 extern int analysis_noisy;
  41
  42 typedef struct {
  43   drft_lookup fft_look;
  44   vorbis_info_mode *mode;
  45   vorbis_info_mapping0 *map;
  46
  47   vorbis_look_time **time_look;
  48   vorbis_look_floor **floor_look;
  49
  50   vorbis_look_residue **residue_look;
  51   vorbis_look_psy *psy_look[2];
  52
  53   vorbis_func_time **time_func;
  54   vorbis_func_floor **floor_func;
  55   vorbis_func_residue **residue_func;
  56
  57   int ch;
  58   long lastframe; /* if a different mode is called, we need to
  59                      invalidate decay */
  60 } vorbis_look_mapping0;
  61
  62 static vorbis_info_mapping *mapping0_copy_info(vorbis_info_mapping *vm){
  63   vorbis_info_mapping0 *info=(vorbis_info_mapping0 *)vm;
  64   vorbis_info_mapping0 *ret=_ogg_malloc(sizeof(vorbis_info_mapping0));
  65   memcpy(ret,info,sizeof(vorbis_info_mapping0));
  66   return(ret);
  67 }
  68
  69 static void mapping0_free_info(vorbis_info_mapping *i){
  70   if(i){
  71     memset(i,0,sizeof(vorbis_info_mapping0));
  72     _ogg_free(i);
  73   }
  74 }
  75
  76 static void mapping0_free_look(vorbis_look_mapping *look){
  77   int i;
  78   vorbis_look_mapping0 *l=(vorbis_look_mapping0 *)look;
  79   if(l){
  80     drft_clear(&l->fft_look);
  81
  82     for(i=0;i<l->map->submaps;i++){
  83       l->time_func[i]->free_look(l->time_look[i]);
  84       l->floor_func[i]->free_look(l->floor_look[i]);
  85       l->residue_func[i]->free_look(l->residue_look[i]);
  86     }
  87     if(l->psy_look[1] && l->psy_look[1]!=l->psy_look[0]){
  88       _vp_psy_clear(l->psy_look[1]);
  89       _ogg_free(l->psy_look[1]);
  90     }
  91     if(l->psy_look[0]){
  92       _vp_psy_clear(l->psy_look[0]);
  93       _ogg_free(l->psy_look[0]);
  94     }
  95     _ogg_free(l->time_func);
  96     _ogg_free(l->floor_func);
  97     _ogg_free(l->residue_func);
  98     _ogg_free(l->time_look);
  99     _ogg_free(l->floor_look);
 100     _ogg_free(l->residue_look);
 101     memset(l,0,sizeof(vorbis_look_mapping0));
 102     _ogg_free(l);
 103   }
 104 }
 105
 106 static vorbis_look_mapping *mapping0_look(vorbis_dsp_state *vd,vorbis_info_mode *vm,
 107                           vorbis_info_mapping *m){
 108   int i;
 109   vorbis_info          *vi=vd->vi;
 110   codec_setup_info     *ci=vi->codec_setup;
 111   vorbis_look_mapping0 *look=_ogg_calloc(1,sizeof(vorbis_look_mapping0));
 112   vorbis_info_mapping0 *info=look->map=(vorbis_info_mapping0 *)m;
 113   look->mode=vm;
 114
 115   look->time_look=_ogg_calloc(info->submaps,sizeof(vorbis_look_time *));
 116   look->floor_look=_ogg_calloc(info->submaps,sizeof(vorbis_look_floor *));
 117
 118   look->residue_look=_ogg_calloc(info->submaps,sizeof(vorbis_look_residue *));
 119
 120   look->time_func=_ogg_calloc(info->submaps,sizeof(vorbis_func_time *));
 121   look->floor_func=_ogg_calloc(info->submaps,sizeof(vorbis_func_floor *));
 122   look->residue_func=_ogg_calloc(info->submaps,sizeof(vorbis_func_residue *));
 123
 124   for(i=0;i<info->submaps;i++){
 125     int timenum=info->timesubmap[i];
 126     int floornum=info->floorsubmap[i];
 127     int resnum=info->residuesubmap[i];
 128
 129     look->time_func[i]=_time_P[ci->time_type[timenum]];
 130     look->time_look[i]=look->time_func[i]->
 131       look(vd,vm,ci->time_param[timenum]);
 132     look->floor_func[i]=_floor_P[ci->floor_type[floornum]];
 133     look->floor_look[i]=look->floor_func[i]->
 134       look(vd,vm,ci->floor_param[floornum]);
 135     look->residue_func[i]=_residue_P[ci->residue_type[resnum]];
 136     look->residue_look[i]=look->residue_func[i]->
 137       look(vd,vm,ci->residue_param[resnum]);
 138
 139   }
 140   if(ci->psys && vd->analysisp){
 141     if(info->psy[0] != info->psy[1]){
 142
 143       int psynum=info->psy[0];
 144       look->psy_look[0]=_ogg_calloc(1,sizeof(vorbis_look_psy));
 145       _vp_psy_init(look->psy_look[0],ci->psy_param[psynum],
 146                    ci->psy_g_param,
 147                    ci->blocksizes[vm->blockflag]/2,vi->rate);
 148
 149       psynum=info->psy[1];
 150       look->psy_look[1]=_ogg_calloc(1,sizeof(vorbis_look_psy));
 151       _vp_psy_init(look->psy_look[1],ci->psy_param[psynum],
 152                    ci->psy_g_param,
 153                    ci->blocksizes[vm->blockflag]/2,vi->rate);
 154     }else{
 155
 156       int psynum=info->psy[0];
 157       look->psy_look[0]=_ogg_calloc(1,sizeof(vorbis_look_psy));
 158       look->psy_look[1]=look->psy_look[0];
 159       _vp_psy_init(look->psy_look[0],ci->psy_param[psynum],
 160                    ci->psy_g_param,
 161                    ci->blocksizes[vm->blockflag]/2,vi->rate);
 162
 163     }
 164   }
 165
 166   look->ch=vi->channels;
 167
 168   if(vd->analysisp)drft_init(&look->fft_look,ci->blocksizes[vm->blockflag]);
 169   return(look);
 170 }
 171
 172 static int ilog2(unsigned int v){
 173   int ret=0;
 174   while(v>1){
 175     ret++;
 176     v>>=1;
 177   }
 178   return(ret);
 179 }
 180
 181 static void mapping0_pack(vorbis_info *vi,vorbis_info_mapping *vm,oggpack_buffer *opb){
 182   int i;
 183   vorbis_info_mapping0 *info=(vorbis_info_mapping0 *)vm;
 184
 185   /* another 'we meant to do it this way' hack...  up to beta 4, we
 186      packed 4 binary zeros here to signify one submapping in use.  We
 187      now redefine that to mean four bitflags that indicate use of
 188      deeper features; bit0:submappings, bit1:coupling,
 189      bit2,3:reserved. This is backward compatable with all actual uses
 190      of the beta code. */
 191
 192   if(info->submaps>1){
 193     oggpack_write(opb,1,1);
 194     oggpack_write(opb,info->submaps-1,4);
 195   }else
 196     oggpack_write(opb,0,1);
 197
 198   if(info->coupling_steps>0){
 199     oggpack_write(opb,1,1);
 200     oggpack_write(opb,info->coupling_steps-1,8);
 201
 202     for(i=0;i<info->coupling_steps;i++){
 203       oggpack_write(opb,info->coupling_mag[i],ilog2(vi->channels));
 204       oggpack_write(opb,info->coupling_ang[i],ilog2(vi->channels));
 205     }
 206   }else
 207     oggpack_write(opb,0,1);
 208
 209   oggpack_write(opb,0,2); /* 2,3:reserved */
 210
 211   /* we don't write the channel submappings if we only have one... */
 212   if(info->submaps>1){
 213     for(i=0;i<vi->channels;i++)
 214       oggpack_write(opb,info->chmuxlist[i],4);
 215   }
 216   for(i=0;i<info->submaps;i++){
 217     oggpack_write(opb,info->timesubmap[i],8);
 218     oggpack_write(opb,info->floorsubmap[i],8);
 219     oggpack_write(opb,info->residuesubmap[i],8);
 220   }
 221 }
 222
 223 /* also responsible for range checking */
 224 static vorbis_info_mapping *mapping0_unpack(vorbis_info *vi,oggpack_buffer *opb){
 225   int i;
 226   vorbis_info_mapping0 *info=_ogg_calloc(1,sizeof(vorbis_info_mapping0));
 227   codec_setup_info     *ci=vi->codec_setup;
 228   memset(info,0,sizeof(vorbis_info_mapping0));
 229
 230   if(oggpack_read(opb,1))
 231     info->submaps=oggpack_read(opb,4)+1;
 232   else
 233     info->submaps=1;
 234
 235   if(oggpack_read(opb,1)){
 236     info->coupling_steps=oggpack_read(opb,8)+1;
 237
 238     for(i=0;i<info->coupling_steps;i++){
 239       int testM=info->coupling_mag[i]=oggpack_read(opb,ilog2(vi->channels));
 240       int testA=info->coupling_ang[i]=oggpack_read(opb,ilog2(vi->channels));
 241
 242       if(testM<0 ||
 243          testA<0 ||
 244          testM==testA ||
 245          testM>=vi->channels ||
 246          testA>=vi->channels) goto err_out;
 247     }
 248
 249   }
 250
 251   if(oggpack_read(opb,2)>0)goto err_out; /* 2,3:reserved */
 252
 253   if(info->submaps>1){
 254     for(i=0;i<vi->channels;i++){
 255       info->chmuxlist[i]=oggpack_read(opb,4);
 256       if(info->chmuxlist[i]>=info->submaps)goto err_out;
 257     }
 258   }
 259   for(i=0;i<info->submaps;i++){
 260     info->timesubmap[i]=oggpack_read(opb,8);
 261     if(info->timesubmap[i]>=ci->times)goto err_out;
 262     info->floorsubmap[i]=oggpack_read(opb,8);
 263     if(info->floorsubmap[i]>=ci->floors)goto err_out;
 264     info->residuesubmap[i]=oggpack_read(opb,8);
 265     if(info->residuesubmap[i]>=ci->residues)goto err_out;
 266   }
 267
 268   return info;
 269
 270  err_out:
 271   mapping0_free_info(info);
 272   return(NULL);
 273 }
 274
 275 #include "os.h"
 276 #include "lpc.h"
 277 #include "lsp.h"
 278 #include "envelope.h"
 279 #include "mdct.h"
 280 #include "psy.h"
 281 #include "scales.h"
 282
 283 /* no time mapping implementation for now */
 284 static long seq=0;
 285 static int mapping0_forward(vorbis_block *vb,vorbis_look_mapping *l){
 286   vorbis_dsp_state      *vd=vb->vd;
 287   vorbis_info           *vi=vd->vi;
 288   codec_setup_info      *ci=vi->codec_setup;
 289   backend_lookup_state  *b=vb->vd->backend_state;
 290   vorbis_look_mapping0  *look=(vorbis_look_mapping0 *)l;
 291   vorbis_info_mapping0  *info=look->map;
 292   vorbis_info_mode      *mode=look->mode;
 293   vorbis_block_internal *vbi=(vorbis_block_internal *)vb->internal;
 294   int                    n=vb->pcmend;
 295   int i,j;
 296   float *window=b->window[vb->W][vb->lW][vb->nW][mode->windowtype];
 297   int   *nonzero=alloca(sizeof(int)*vi->channels);
 298
 299   float *work=_vorbis_block_alloc(vb,n*sizeof(float));
 300
 301   float global_ampmax=vbi->ampmax;
 302   float *local_ampmax=alloca(sizeof(float)*vi->channels);
 303   int blocktype;
 304
 305   /* we differentiate between short and long block types to help the
 306      masking engine; the window shapes also matter.
 307      impulse block (a short block in which an impulse occurs)
 308      padding block (a short block that pads between a transitional
 309           long block and an impulse block, or vice versa)
 310      transition block (the wqeird one; a long block with the transition
 311           window; affects bass/midrange response and that must be
 312           accounted for in masking)
 313      long block (run of the mill long block)
 314   */
 315
 316   if(vb->W){
 317     if(!vb->lW || !vb->nW)
 318       blocktype=BLOCKTYPE_TRANSITION;
 319     else
 320       blocktype=BLOCKTYPE_LONG;
 321   }else{
 322     /* right now we're missing the infrastructure to distingush the
 323        two short types */
 324     blocktype=BLOCKTYPE_IMPULSE;
 325   }
 326
 327   for(i=0;i<vi->channels;i++){
 328     float scale=4.f/n;
 329
 330     /* the following makes things clearer to *me* anyway */
 331     float *pcm     =vb->pcm[i];
 332     float *fft     =work;
 333     float *logfft  =pcm+n/2;
 334
 335     /*float *res     =pcm;
 336     float *mdct    =pcm;
 337     float *codedflr=pcm+n/2;
 338     float *logmax  =work;
 339     float *logmask =work+n/2;*/
 340
 341     /* window the PCM data */
 342     for(j=0;j<n;j++)
 343       fft[j]=pcm[j]*=window[j];
 344
 345     /* transform the PCM data */
 346     /* only MDCT right now.... */
 347     mdct_forward(b->transform[vb->W][0],pcm,pcm);
 348
 349     /* FFT yields more accurate tonal estimation (not phase sensitive) */
 350     drft_forward(&look->fft_look,fft);
 351     fft[0]*=scale;
 352     logfft[0]=todB(fft);
 353     local_ampmax[i]=logfft[0];
 354     for(j=1;j<n-1;j+=2){
 355       float temp=scale*FAST_HYPOT(fft[j],fft[j+1]);
 356       temp=logfft[(j+1)>>1]=todB(&temp);
 357       if(temp>local_ampmax[i])local_ampmax[i]=temp;
 358     }
 359     if(local_ampmax[i]>global_ampmax)global_ampmax=local_ampmax[i];
 360
 361     _analysis_output("fft",seq+i,logfft,n/2,1,0);
 362   }
 363
 364   for(i=0;i<vi->channels;i++){
 365     int submap=info->chmuxlist[i];
 366
 367     /* the following makes things clearer to *me* anyway */
 368     float *mdct    =vb->pcm[i];
 369     float *res     =mdct;
 370     float *codedflr=mdct+n/2;
 371     float *logfft  =mdct+n/2;
 372
 373     float *logmdct =work;
 374     float *logmax  =mdct+n/2;
 375     float *logmask =work+n/2;
 376
 377     for(j=0;j<n/2;j++)
 378       logmdct[j]=todB(mdct+j);
 379     _analysis_output("mdct",seq+i,logmdct,n/2,1,0);
 380
 381
 382     /* perform psychoacoustics; do masking */
 383     _vp_compute_mask(look->psy_look[blocktype],
 384                      b->psy_g_look,
 385                      i,
 386                      logfft, /* -> logmax */
 387                      logmdct,
 388                      logmask,
 389                      global_ampmax,
 390                      local_ampmax[i],
 391                      ci->blocksizes[vb->lW]/2);
 392
 393     _analysis_output("mask",seq+i,logmask,n/2,1,0);
 394
 395     /* perform floor encoding */
 396     nonzero[i]=look->floor_func[submap]->
 397       forward(vb,look->floor_look[submap],
 398               mdct,
 399               logmdct,
 400               logmask,
 401               logmax,
 402
 403               codedflr);
 404
 405
 406     _analysis_output("mdct2",seq+i,mdct,n/2,1,1);
 407     _vp_remove_floor(look->psy_look[blocktype],
 408                      b->psy_g_look,
 409                      logmdct,
 410                      mdct,
 411                      codedflr,
 412                      res,
 413                      local_ampmax[i]);
 414
 415     /*for(j=0;j<n/2;j++)
 416       if(fabs(res[j])>1200){
 417         analysis_noisy=1;
 418         fprintf(stderr,"%ld ",seq+i);
 419         }*/
 420
 421     _analysis_output("res",seq+i,res,n/2,1,0);
 422     _analysis_output("codedflr",seq+i,codedflr,n/2,1,1);
 423
 424   }
 425
 426   vbi->ampmax=global_ampmax;
 427
 428   /* partition based prequantization and channel coupling */
 429   /* Steps in prequant and coupling:
 430
 431      down-couple/down-quantize from perfect residue ->  quantized vector
 432      classify by this first quantized vector
 433
 434      do{
 435         encode quantized vector; add encoded values to 'so-far' vector
 436         more? [not yet at bitrate/not yet at target]
 437           yes{
 438               down-couple/down-quantize from perfect-'so-far' ->
 439                 quantized vector; when subtracting coupling,
 440                 account for +/- out-of-phase component
 441           }no{
 442               break
 443           }
 444      }
 445      done.
 446
 447      quantization in each iteration is done (after circular normalization
 448      in coupling) using a by-iteration quantization granule value.
 449   */
 450
 451   {
 452     float  **pcm=vb->pcm;
 453     float  **quantized=alloca(sizeof(float*)*vi->channels);
 454     float  **sofar=alloca(sizeof(float*)*vi->channels);
 455
 456     long  ***classifications=alloca(sizeof(long**)*info->submaps);
 457     float ***pcmbundle=alloca(sizeof(float **)*info->submaps);
 458     float ***sobundle=alloca(sizeof(float **)*info->submaps);
 459     int    **zerobundle=alloca(sizeof(int *)*info->submaps);
 460     int     *chbundle=alloca(sizeof(int)*info->submaps);
 461     int      chcounter=0;
 462
 463     /* play a little loose with this abstraction */
 464     int   quant_passes=look->psy_look[blocktype]->vi->coupling_passes;
 465     int   stopflag=0;
 466
 467     for(i=0;i<vi->channels;i++){
 468       quantized[i]=pcm[i]+n/2;
 469       sofar[i]=_vorbis_block_alloc(vb,n/2*sizeof(float));
 470       memset(sofar[i],0,sizeof(float)*n/2);
 471     }
 472
 473     pcmbundle[0]=alloca(sizeof(float *)*vi->channels);
 474     sobundle[0]=alloca(sizeof(float *)*vi->channels);
 475     zerobundle[0]=alloca(sizeof(int)*vi->channels);
 476
 477     /* initial down-quantized coupling */
 478
 479     if(info->coupling_steps==0){
 480       /* this assumes all or nothing coupling right now.  it should pass
 481          through any channels left uncoupled, but it doesn't do that now */
 482       for(i=0;i<vi->channels;i++){
 483         float *lpcm=pcm[i];
 484         float *lqua=quantized[i];
 485         for(j=0;j<n/2;j++)
 486           lqua[j]=lpcm[j];
 487       }
 488     }else{
 489       _vp_quantize_couple(look->psy_look[blocktype],
 490                           info,
 491                           pcm,
 492                           sofar,
 493                           quantized,
 494                           nonzero,
 495                           0);
 496     }
 497
 498     for(i=0;i<vi->channels;i++)
 499       _analysis_output("quant",seq+i,quantized[i],n/2,1,0);
 500
 501
 502     /* classify, by submap */
 503
 504     for(i=0;i<info->submaps;i++){
 505       int ch_in_bundle=0;
 506       pcmbundle[i]=pcmbundle[0]+chcounter;
 507       sobundle[i]=sobundle[0]+chcounter;
 508       zerobundle[i]=zerobundle[0]+chcounter;
 509
 510       for(j=0;j<vi->channels;j++){
 511         if(info->chmuxlist[j]==i){
 512           if(nonzero[j])
 513             zerobundle[i][ch_in_bundle]=1;
 514           else
 515             zerobundle[i][ch_in_bundle]=0;
 516           pcmbundle[i][ch_in_bundle]=quantized[j];
 517           sobundle[i][ch_in_bundle++]=sofar[j];
 518         }
 519       }
 520       chbundle[i]=ch_in_bundle;
 521       chcounter+=ch_in_bundle;
 522
 523       classifications[i]=look->residue_func[i]->
 524         class(vb,look->residue_look[i],pcmbundle[i],zerobundle[i],chbundle[i]);
 525     }
 526
 527     /* actual encoding loop */
 528     for(i=0;!stopflag;){
 529
 530       /* perform residue encoding of this pass's quantized residue
 531          vector, according residue mapping */
 532
 533       for(j=0;j<info->submaps;j++)
 534         look->residue_func[j]->
 535           forward(vb,look->residue_look[j],
 536                   pcmbundle[j],sobundle[j],zerobundle[j],chbundle[j],
 537                   i,classifications[j]);
 538       i++;
 539
 540       /* bitrate management decision hook; the following if() is where
 541          we tell progressive encoding to halt, right now it just
 542          avoids falling off the edge */
 543       if(i>=quant_passes /* || yadda yadda */)stopflag=1;
 544
 545       if(!stopflag){
 546         /* down-couple/down-quantize from perfect-'so-far' ->
 547            new quantized vector */
 548         if(info->coupling_steps==0){
 549           /* this assumes all or nothing coupling right now.  it should pass
 550              through any channels left uncoupled, but it doesn't do that now */
 551           for(i=0;i<vi->channels;i++){
 552             float *lpcm=pcm[i];
 553             float *lsof=sofar[i];
 554             float *lqua=quantized[i];
 555             for(j=0;j<n/2;j++)
 556               lqua[j]=lpcm[j]-lsof[j];
 557           }
 558         }else{
 559           _vp_quantize_couple(look->psy_look[blocktype],
 560                               info,
 561                               pcm,
 562                               sofar,
 563                               quantized,
 564                               nonzero,
 565                               i);
 566         }
 567       }
 568       /* steady as she goes */
 569     }
 570     seq+=vi->channels;
 571   }
 572
 573   look->lastframe=vb->sequence;
 574   return(0);
 575 }
 576
 577 static int mapping0_inverse(vorbis_block *vb,vorbis_look_mapping *l){
 578   vorbis_dsp_state     *vd=vb->vd;
 579   vorbis_info          *vi=vd->vi;
 580   codec_setup_info     *ci=vi->codec_setup;
 581   backend_lookup_state *b=vd->backend_state;
 582   vorbis_look_mapping0 *look=(vorbis_look_mapping0 *)l;
 583   vorbis_info_mapping0 *info=look->map;
 584   vorbis_info_mode     *mode=look->mode;
 585   int                   i,j;
 586   long                  n=vb->pcmend=ci->blocksizes[vb->W];
 587
 588   float *window=b->window[vb->W][vb->lW][vb->nW][mode->windowtype];
 589   float **pcmbundle=alloca(sizeof(float *)*vi->channels);
 590   int    *zerobundle=alloca(sizeof(int)*vi->channels);
 591
 592   int   *nonzero  =alloca(sizeof(int)*vi->channels);
 593   void **floormemo=alloca(sizeof(void *)*vi->channels);
 594
 595   /* time domain information decode (note that applying the
 596      information would have to happen later; we'll probably add a
 597      function entry to the harness for that later */
 598   /* NOT IMPLEMENTED */
 599
 600   /* recover the spectral envelope; store it in the PCM vector for now */
 601   for(i=0;i<vi->channels;i++){
 602     int submap=info->chmuxlist[i];
 603     floormemo[i]=look->floor_func[submap]->
 604       inverse1(vb,look->floor_look[submap]);
 605     if(floormemo[i])
 606       nonzero[i]=1;
 607     else
 608       nonzero[i]=0;
 609     memset(vb->pcm[i],0,sizeof(float)*n/2);
 610   }
 611
 612   /* channel coupling can 'dirty' the nonzero listing */
 613   for(i=0;i<info->coupling_steps;i++){
 614     if(nonzero[info->coupling_mag[i]] ||
 615        nonzero[info->coupling_ang[i]]){
 616       nonzero[info->coupling_mag[i]]=1;
 617       nonzero[info->coupling_ang[i]]=1;
 618     }
 619   }
 620
 621   /* recover the residue into our working vectors */
 622   for(i=0;i<info->submaps;i++){
 623     int ch_in_bundle=0;
 624     for(j=0;j<vi->channels;j++){
 625       if(info->chmuxlist[j]==i){
 626         if(nonzero[j])
 627           zerobundle[ch_in_bundle]=1;
 628         else
 629           zerobundle[ch_in_bundle]=0;
 630         pcmbundle[ch_in_bundle++]=vb->pcm[j];
 631       }
 632     }
 633
 634     look->residue_func[i]->inverse(vb,look->residue_look[i],
 635                                    pcmbundle,zerobundle,ch_in_bundle);
 636   }
 637
 638   /* channel coupling */
 639   for(i=info->coupling_steps-1;i>=0;i--){
 640     float *pcmM=vb->pcm[info->coupling_mag[i]];
 641     float *pcmA=vb->pcm[info->coupling_ang[i]];
 642
 643     for(j=0;j<n/2;j++){
 644       float mag=pcmM[j];
 645       float ang=pcmA[j];
 646
 647       if(mag>0)
 648         if(ang>0){
 649           pcmM[j]=mag;
 650           pcmA[j]=mag-ang;
 651         }else{
 652           pcmA[j]=mag;
 653           pcmM[j]=mag+ang;
 654         }
 655       else
 656         if(ang>0){
 657           pcmM[j]=mag;
 658           pcmA[j]=mag+ang;
 659         }else{
 660           pcmA[j]=mag;
 661           pcmM[j]=mag-ang;
 662         }
 663     }
 664   }
 665
 666   /* compute and apply spectral envelope */
 667   for(i=0;i<vi->channels;i++){
 668     float *pcm=vb->pcm[i];
 669     int submap=info->chmuxlist[i];
 670     look->floor_func[submap]->
 671       inverse2(vb,look->floor_look[submap],floormemo[i],pcm);
 672   }
 673
 674   /* transform the PCM data; takes PCM vector, vb; modifies PCM vector */
 675   /* only MDCT right now.... */
 676   for(i=0;i<vi->channels;i++){
 677     float *pcm=vb->pcm[i];
 678     _analysis_output("out",seq+i,pcm,n/2,1,1);
 679     mdct_backward(b->transform[vb->W][0],pcm,pcm);
 680   }
 681
 682   /* window the data */
 683   for(i=0;i<vi->channels;i++){
 684     float *pcm=vb->pcm[i];
 685     if(nonzero[i])
 686       for(j=0;j<n;j++)
 687         pcm[j]*=window[j];
 688     else
 689       for(j=0;j<n;j++)
 690         pcm[j]=0.f;
 691     _analysis_output("final",seq++,pcm,n,0,0);
 692   }
 693
 694   /* now apply the decoded post-window time information */
 695   /* NOT IMPLEMENTED */
 696
 697   /* all done! */
 698   return(0);
 699 }
 700
 701 /* export hooks */
 702 vorbis_func_mapping mapping0_exportbundle={
 703   &mapping0_pack,
 704   &mapping0_unpack,
 705   &mapping0_look,
 706   &mapping0_copy_info,
 707   &mapping0_free_info,
 708   &mapping0_free_look,
 709   &mapping0_forward,
 710   &mapping0_inverse
 711 };