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 1.42 2001/12/19 01:08:14 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 "registry.h"
  27 #include "psy.h"
  28 #include "misc.h"
  29
  30 /* simplistic, wasteful way of doing this (unique lookup for each
  31    mode/submapping); there should be a central repository for
  32    identical lookups.  That will require minor work, so I'm putting it
  33    off as low priority.
  34
  35    Why a lookup for each backend in a given mode?  Because the
  36    blocksize is set by the mode, and low backend lookups may require
  37    parameters from other areas of the mode/mapping */
  38
  39 extern int analysis_noisy;
  40
  41 typedef struct {
  42   drft_lookup fft_look;
  43   vorbis_info_mode *mode;
  44   vorbis_info_mapping0 *map;
  45
  46   vorbis_look_time **time_look;
  47   vorbis_look_floor **floor_look;
  48
  49   vorbis_look_residue **residue_look;
  50   vorbis_look_psy *psy_look[2];
  51
  52   vorbis_func_time **time_func;
  53   vorbis_func_floor **floor_func;
  54   vorbis_func_residue **residue_func;
  55
  56   int ch;
  57   long lastframe; /* if a different mode is called, we need to
  58                      invalidate decay */
  59 } vorbis_look_mapping0;
  60
  61 static vorbis_info_mapping *mapping0_copy_info(vorbis_info_mapping *vm){
  62   vorbis_info_mapping0 *info=(vorbis_info_mapping0 *)vm;
  63   vorbis_info_mapping0 *ret=_ogg_malloc(sizeof(*ret));
  64   memcpy(ret,info,sizeof(*ret));
  65   return(ret);
  66 }
  67
  68 static void mapping0_free_info(vorbis_info_mapping *i){
  69   vorbis_info_mapping0 *info=(vorbis_info_mapping0 *)i;
  70   if(info){
  71     memset(info,0,sizeof(*info));
  72     _ogg_free(info);
  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(*l));
 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(*look));
 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(*look->time_look));
 116   look->floor_look=_ogg_calloc(info->submaps,sizeof(*look->floor_look));
 117
 118   look->residue_look=_ogg_calloc(info->submaps,sizeof(*look->residue_look));
 119
 120   look->time_func=_ogg_calloc(info->submaps,sizeof(*look->time_func));
 121   look->floor_func=_ogg_calloc(info->submaps,sizeof(*look->floor_func));
 122   look->residue_func=_ogg_calloc(info->submaps,sizeof(*look->residue_func));
 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(*look->psy_look[0]));
 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(*look->psy_look[1]));
 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(*look->psy_look[0]));
 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,
 182                           oggpack_buffer *opb){
 183   int i;
 184   vorbis_info_mapping0 *info=(vorbis_info_mapping0 *)vm;
 185
 186   /* another 'we meant to do it this way' hack...  up to beta 4, we
 187      packed 4 binary zeros here to signify one submapping in use.  We
 188      now redefine that to mean four bitflags that indicate use of
 189      deeper features; bit0:submappings, bit1:coupling,
 190      bit2,3:reserved. This is backward compatable with all actual uses
 191      of the beta code. */
 192
 193   if(info->submaps>1){
 194     oggpack_write(opb,1,1);
 195     oggpack_write(opb,info->submaps-1,4);
 196   }else
 197     oggpack_write(opb,0,1);
 198
 199   if(info->coupling_steps>0){
 200     oggpack_write(opb,1,1);
 201     oggpack_write(opb,info->coupling_steps-1,8);
 202
 203     for(i=0;i<info->coupling_steps;i++){
 204       oggpack_write(opb,info->coupling_mag[i],ilog2(vi->channels));
 205       oggpack_write(opb,info->coupling_ang[i],ilog2(vi->channels));
 206     }
 207   }else
 208     oggpack_write(opb,0,1);
 209
 210   oggpack_write(opb,0,2); /* 2,3:reserved */
 211
 212   /* we don't write the channel submappings if we only have one... */
 213   if(info->submaps>1){
 214     for(i=0;i<vi->channels;i++)
 215       oggpack_write(opb,info->chmuxlist[i],4);
 216   }
 217   for(i=0;i<info->submaps;i++){
 218     oggpack_write(opb,info->timesubmap[i],8);
 219     oggpack_write(opb,info->floorsubmap[i],8);
 220     oggpack_write(opb,info->residuesubmap[i],8);
 221   }
 222 }
 223
 224 /* also responsible for range checking */
 225 static vorbis_info_mapping *mapping0_unpack(vorbis_info *vi,oggpack_buffer *opb){
 226   int i;
 227   vorbis_info_mapping0 *info=_ogg_calloc(1,sizeof(*info));
 228   codec_setup_info     *ci=vi->codec_setup;
 229   memset(info,0,sizeof(*info));
 230
 231   if(oggpack_read(opb,1))
 232     info->submaps=oggpack_read(opb,4)+1;
 233   else
 234     info->submaps=1;
 235
 236   if(oggpack_read(opb,1)){
 237     info->coupling_steps=oggpack_read(opb,8)+1;
 238
 239     for(i=0;i<info->coupling_steps;i++){
 240       int testM=info->coupling_mag[i]=oggpack_read(opb,ilog2(vi->channels));
 241       int testA=info->coupling_ang[i]=oggpack_read(opb,ilog2(vi->channels));
 242
 243       if(testM<0 ||
 244          testA<0 ||
 245          testM==testA ||
 246          testM>=vi->channels ||
 247          testA>=vi->channels) goto err_out;
 248     }
 249
 250   }
 251
 252   if(oggpack_read(opb,2)>0)goto err_out; /* 2,3:reserved */
 253
 254   if(info->submaps>1){
 255     for(i=0;i<vi->channels;i++){
 256       info->chmuxlist[i]=oggpack_read(opb,4);
 257       if(info->chmuxlist[i]>=info->submaps)goto err_out;
 258     }
 259   }
 260   for(i=0;i<info->submaps;i++){
 261     info->timesubmap[i]=oggpack_read(opb,8);
 262     if(info->timesubmap[i]>=ci->times)goto err_out;
 263     info->floorsubmap[i]=oggpack_read(opb,8);
 264     if(info->floorsubmap[i]>=ci->floors)goto err_out;
 265     info->residuesubmap[i]=oggpack_read(opb,8);
 266     if(info->residuesubmap[i]>=ci->residues)goto err_out;
 267   }
 268
 269   return info;
 270
 271  err_out:
 272   mapping0_free_info(info);
 273   return(NULL);
 274 }
 275
 276 #include "os.h"
 277 #include "lpc.h"
 278 #include "lsp.h"
 279 #include "envelope.h"
 280 #include "mdct.h"
 281 #include "psy.h"
 282 #include "scales.h"
 283
 284 /* no time mapping implementation for now */
 285 static long seq=0;
 286 static int mapping0_forward(vorbis_block *vb,vorbis_look_mapping *l){
 287   vorbis_dsp_state      *vd=vb->vd;
 288   vorbis_info           *vi=vd->vi;
 289   codec_setup_info      *ci=vi->codec_setup;
 290   backend_lookup_state  *b=vb->vd->backend_state;
 291   bitrate_manager_state *bm=&b->bms;
 292   vorbis_look_mapping0  *look=(vorbis_look_mapping0 *)l;
 293   vorbis_info_mapping0  *info=look->map;
 294   vorbis_info_mode      *mode=look->mode;
 295   vorbis_block_internal *vbi=(vorbis_block_internal *)vb->internal;
 296   int                    n=vb->pcmend;
 297   int i,j;
 298   float *window=b->window[vb->W][vb->lW][vb->nW][mode->windowtype];
 299   int   *nonzero=alloca(sizeof(*nonzero)*vi->channels);
 300
 301   float *work=_vorbis_block_alloc(vb,n*sizeof(*work));
 302
 303   float global_ampmax=vbi->ampmax;
 304   float *local_ampmax=alloca(sizeof(*local_ampmax)*vi->channels);
 305   int blocktype=vbi->blocktype;
 306
 307   /* we differentiate between short and long block types to help the
 308      masking engine; the window shapes also matter.
 309      impulse block (a short block in which an impulse occurs)
 310      padding block (a short block that pads between a transitional
 311           long block and an impulse block, or vice versa)
 312      transition block (the wqeird one; a long block with the transition
 313           window; affects bass/midrange response and that must be
 314           accounted for in masking)
 315      long block (run of the mill long block)
 316   */
 317
 318   for(i=0;i<vi->channels;i++){
 319     float scale=4.f/n;
 320     float scale_dB;
 321
 322     /* the following makes things clearer to *me* anyway */
 323     float *pcm     =vb->pcm[i];
 324     float *fft     =work;
 325     float *logfft  =pcm+n/2;
 326
 327     /*float *res     =pcm;
 328     float *mdct    =pcm;
 329     float *codedflr=pcm+n/2;
 330     float *logmax  =work;
 331     float *logmask =work+n/2;*/
 332
 333     scale_dB=todB(&scale);
 334     _analysis_output("pcm",seq+i,pcm,n,0,0);
 335
 336     /* window the PCM data */
 337     for(j=0;j<n;j++)
 338       fft[j]=pcm[j]*=window[j];
 339
 340     //_analysis_output("windowed",seq+i,pcm,n,0,0);
 341
 342     /* transform the PCM data */
 343     /* only MDCT right now.... */
 344     mdct_forward(b->transform[vb->W][0],pcm,pcm);
 345
 346     /* FFT yields more accurate tonal estimation (not phase sensitive) */
 347     drft_forward(&look->fft_look,fft);
 348     fft[0]*=scale;
 349     logfft[0]=todB(fft);
 350     local_ampmax[i]=logfft[0];
 351     for(j=1;j<n-1;j+=2){
 352       float temp=fft[j]*fft[j]+fft[j+1]*fft[j+1];
 353       temp=logfft[(j+1)>>1]=scale_dB+.5f*todB(&temp);
 354       if(temp>local_ampmax[i])local_ampmax[i]=temp;
 355     }
 356
 357     if(local_ampmax[i]>0.f)local_ampmax[i]=0.f;
 358     if(local_ampmax[i]>global_ampmax)global_ampmax=local_ampmax[i];
 359
 360     _analysis_output("fft",seq+i,logfft,n/2,1,0);
 361   }
 362
 363   for(i=0;i<vi->channels;i++){
 364     int submap=info->chmuxlist[i];
 365
 366     /* the following makes things clearer to *me* anyway */
 367     float *mdct    =vb->pcm[i];
 368     float *res     =mdct;
 369     float *codedflr=mdct+n/2;
 370     float *logfft  =mdct+n/2;
 371
 372     float *logmdct =work;
 373     float *logmax  =mdct+n/2;
 374     float *logmask =work+n/2;
 375
 376     for(j=0;j<n/2;j++)
 377       logmdct[j]=todB(mdct+j);
 378     _analysis_output("mdct",seq+i,logmdct,n/2,1,0);
 379
 380
 381     /* perform psychoacoustics; do masking */
 382     _vp_compute_mask(look->psy_look[blocktype],
 383                      logfft, /* -> logmax */
 384                      logmdct,
 385                      logmask,
 386                      global_ampmax,
 387                      local_ampmax[i],
 388                      bm->avgnoise);
 389
 390     _analysis_output("mask",seq+i,logmask,n/2,1,0);
 391     /* perform floor encoding */
 392     nonzero[i]=look->floor_func[submap]->
 393       forward(vb,look->floor_look[submap],
 394               mdct,
 395               logmdct,
 396               logmask,
 397               logmax,
 398
 399               codedflr);
 400
 401
 402     _vp_remove_floor(look->psy_look[blocktype],
 403                      mdct,
 404                      codedflr,
 405                      res);
 406
 407     /*for(j=0;j<n/2;j++)
 408       if(fabs(res[j])>1200){
 409         analysis_noisy=1;
 410         fprintf(stderr,"%ld ",seq+i);
 411         }*/
 412
 413     _analysis_output("codedflr",seq+i,codedflr,n/2,1,1);
 414
 415   }
 416
 417   vbi->ampmax=global_ampmax;
 418
 419   /* partition based prequantization and channel coupling */
 420   /* Steps in prequant and coupling:
 421
 422      classify by |mag| across all pcm vectors
 423
 424      down-couple/down-quantize from perfect residue ->  quantized vector
 425
 426      do{
 427         encode quantized vector; add encoded values to 'so-far' vector
 428         more? [not yet at bitrate/not yet at target]
 429           yes{
 430               down-couple/down-quantize from perfect-'so-far' ->
 431                 quantized vector; when subtracting coupling,
 432                 account for +/- out-of-phase component
 433           }no{
 434               break
 435           }
 436      }
 437      done.
 438
 439      quantization in each iteration is done (after circular normalization
 440      in coupling) using a by-iteration quantization granule value.
 441   */
 442
 443   {
 444     float  **pcm=vb->pcm;
 445     float  **quantized=alloca(sizeof(*quantized)*vi->channels);
 446     float  **sofar=alloca(sizeof(*sofar)*vi->channels);
 447
 448     long  ***classifications=alloca(sizeof(*classifications)*info->submaps);
 449     float ***qbundle=alloca(sizeof(*qbundle)*info->submaps);
 450     float ***pcmbundle=alloca(sizeof(*pcmbundle)*info->submaps);
 451     float ***sobundle=alloca(sizeof(*sobundle)*info->submaps);
 452     int    **zerobundle=alloca(sizeof(*zerobundle)*info->submaps);
 453     int     *chbundle=alloca(sizeof(*chbundle)*info->submaps);
 454     int      chcounter=0;
 455
 456     /* play a little loose with this abstraction */
 457     int   quant_passes=ci->coupling_passes;
 458
 459     for(i=0;i<vi->channels;i++){
 460       quantized[i]=_vorbis_block_alloc(vb,n*sizeof(*sofar[i]));
 461       sofar[i]=quantized[i]+n/2;
 462       memset(sofar[i],0,sizeof(*sofar[i])*n/2);
 463     }
 464
 465     qbundle[0]=alloca(sizeof(*qbundle[0])*vi->channels);
 466     pcmbundle[0]=alloca(sizeof(*pcmbundle[0])*vi->channels);
 467     sobundle[0]=alloca(sizeof(*sobundle[0])*vi->channels);
 468     zerobundle[0]=alloca(sizeof(*zerobundle[0])*vi->channels);
 469
 470     /* initial down-quantized coupling */
 471
 472     if(info->coupling_steps==0){
 473       /* this assumes all or nothing coupling right now.  it should pass
 474          through any channels left uncoupled, but it doesn't do that now */
 475       for(i=0;i<vi->channels;i++){
 476         float *lpcm=pcm[i];
 477         float *lqua=quantized[i];
 478         for(j=0;j<n/2;j++)
 479           lqua[j]=lpcm[j];
 480       }
 481     }else{
 482       _vp_quantize_couple(look->psy_look[blocktype],
 483                           info,
 484                           pcm,
 485                           sofar,
 486                           quantized,
 487                           nonzero,
 488                           0);
 489     }
 490
 491     for(i=0;i<vi->channels;i++)
 492       _analysis_output("quant",seq+i,quantized[i],n/2,1,0);
 493
 494
 495     /* classify, by submap */
 496
 497     for(i=0;i<info->submaps;i++){
 498       int ch_in_bundle=0;
 499       qbundle[i]=qbundle[0]+chcounter;
 500       sobundle[i]=sobundle[0]+chcounter;
 501       zerobundle[i]=zerobundle[0]+chcounter;
 502
 503       for(j=0;j<vi->channels;j++){
 504         if(info->chmuxlist[j]==i){
 505           if(nonzero[j])
 506             zerobundle[i][ch_in_bundle]=1;
 507           else
 508             zerobundle[i][ch_in_bundle]=0;
 509           qbundle[i][ch_in_bundle]=quantized[j];
 510           pcmbundle[i][ch_in_bundle]=pcm[j];
 511           sobundle[i][ch_in_bundle++]=sofar[j];
 512         }
 513       }
 514       chbundle[i]=ch_in_bundle;
 515       chcounter+=ch_in_bundle;
 516
 517       classifications[i]=look->residue_func[i]->
 518         class(vb,look->residue_look[i],pcmbundle[i],zerobundle[i],chbundle[i]);
 519     }
 520
 521     /* actual encoding loop; we pack all the iterations to collect
 522        management data */
 523
 524     for(i=0;i<quant_passes;){
 525
 526       /* perform residue encoding of this pass's quantized residue
 527          vector, according residue mapping */
 528
 529       for(j=0;j<info->submaps;j++){
 530         look->residue_func[j]->
 531           forward(vb,look->residue_look[j],
 532                   qbundle[j],sobundle[j],zerobundle[j],chbundle[j],
 533                   i,classifications[j],vbi->packet_markers);
 534
 535       }
 536       i++;
 537
 538       if(i<quant_passes){
 539         /* down-couple/down-quantize from perfect-'so-far' ->
 540          new quantized vector */
 541         if(info->coupling_steps==0){
 542           /* this assumes all or nothing coupling right now.  it should pass
 543              through any channels left uncoupled, but it doesn't do that now */
 544           int k;
 545           for(k=0;k<vi->channels;k++){
 546             float *lpcm=pcm[k];
 547             float *lsof=sofar[k];
 548             float *lqua=quantized[k];
 549             for(j=0;j<n/2;j++)
 550               lqua[j]=lpcm[j]-lsof[j];
 551           }
 552         }else{
 553
 554           _vp_quantize_couple(look->psy_look[blocktype],
 555                               info,
 556                               pcm,
 557                               sofar,
 558                               quantized,
 559                               nonzero,
 560                               i);
 561         }
 562       }
 563     }
 564     seq+=vi->channels;
 565   }
 566
 567   look->lastframe=vb->sequence;
 568   return(0);
 569 }
 570
 571 static int mapping0_inverse(vorbis_block *vb,vorbis_look_mapping *l){
 572   vorbis_dsp_state     *vd=vb->vd;
 573   vorbis_info          *vi=vd->vi;
 574   codec_setup_info     *ci=vi->codec_setup;
 575   backend_lookup_state *b=vd->backend_state;
 576   vorbis_look_mapping0 *look=(vorbis_look_mapping0 *)l;
 577   vorbis_info_mapping0 *info=look->map;
 578   vorbis_info_mode     *mode=look->mode;
 579   int                   i,j;
 580   long                  n=vb->pcmend=ci->blocksizes[vb->W];
 581
 582   float *window=b->window[vb->W][vb->lW][vb->nW][mode->windowtype];
 583   float **pcmbundle=alloca(sizeof(*pcmbundle)*vi->channels);
 584   int    *zerobundle=alloca(sizeof(*zerobundle)*vi->channels);
 585
 586   int   *nonzero  =alloca(sizeof(*nonzero)*vi->channels);
 587   void **floormemo=alloca(sizeof(*floormemo)*vi->channels);
 588
 589   /* time domain information decode (note that applying the
 590      information would have to happen later; we'll probably add a
 591      function entry to the harness for that later */
 592   /* NOT IMPLEMENTED */
 593
 594   /* recover the spectral envelope; store it in the PCM vector for now */
 595   for(i=0;i<vi->channels;i++){
 596     int submap=info->chmuxlist[i];
 597     floormemo[i]=look->floor_func[submap]->
 598       inverse1(vb,look->floor_look[submap]);
 599     if(floormemo[i])
 600       nonzero[i]=1;
 601     else
 602       nonzero[i]=0;
 603     memset(vb->pcm[i],0,sizeof(*vb->pcm[i])*n/2);
 604   }
 605
 606   /* channel coupling can 'dirty' the nonzero listing */
 607   for(i=0;i<info->coupling_steps;i++){
 608     if(nonzero[info->coupling_mag[i]] ||
 609        nonzero[info->coupling_ang[i]]){
 610       nonzero[info->coupling_mag[i]]=1;
 611       nonzero[info->coupling_ang[i]]=1;
 612     }
 613   }
 614
 615   /* recover the residue into our working vectors */
 616   for(i=0;i<info->submaps;i++){
 617     int ch_in_bundle=0;
 618     for(j=0;j<vi->channels;j++){
 619       if(info->chmuxlist[j]==i){
 620         if(nonzero[j])
 621           zerobundle[ch_in_bundle]=1;
 622         else
 623           zerobundle[ch_in_bundle]=0;
 624         pcmbundle[ch_in_bundle++]=vb->pcm[j];
 625       }
 626     }
 627
 628     look->residue_func[i]->inverse(vb,look->residue_look[i],
 629                                    pcmbundle,zerobundle,ch_in_bundle);
 630   }
 631
 632   /* channel coupling */
 633   for(i=info->coupling_steps-1;i>=0;i--){
 634     float *pcmM=vb->pcm[info->coupling_mag[i]];
 635     float *pcmA=vb->pcm[info->coupling_ang[i]];
 636
 637     for(j=0;j<n/2;j++){
 638       float mag=pcmM[j];
 639       float ang=pcmA[j];
 640
 641       if(mag>0)
 642         if(ang>0){
 643           pcmM[j]=mag;
 644           pcmA[j]=mag-ang;
 645         }else{
 646           pcmA[j]=mag;
 647           pcmM[j]=mag+ang;
 648         }
 649       else
 650         if(ang>0){
 651           pcmM[j]=mag;
 652           pcmA[j]=mag+ang;
 653         }else{
 654           pcmA[j]=mag;
 655           pcmM[j]=mag-ang;
 656         }
 657     }
 658   }
 659
 660   /* compute and apply spectral envelope */
 661   for(i=0;i<vi->channels;i++){
 662     float *pcm=vb->pcm[i];
 663     int submap=info->chmuxlist[i];
 664     look->floor_func[submap]->
 665       inverse2(vb,look->floor_look[submap],floormemo[i],pcm);
 666   }
 667
 668   /* transform the PCM data; takes PCM vector, vb; modifies PCM vector */
 669   /* only MDCT right now.... */
 670   for(i=0;i<vi->channels;i++){
 671     float *pcm=vb->pcm[i];
 672     mdct_backward(b->transform[vb->W][0],pcm,pcm);
 673   }
 674
 675   /* window the data */
 676   for(i=0;i<vi->channels;i++){
 677     float *pcm=vb->pcm[i];
 678     if(nonzero[i])
 679       for(j=0;j<n;j++)
 680         pcm[j]*=window[j];
 681     else
 682       for(j=0;j<n;j++)
 683         pcm[j]=0.f;
 684
 685   }
 686
 687   /* all done! */
 688   return(0);
 689 }
 690
 691 /* export hooks */
 692 vorbis_func_mapping mapping0_exportbundle={
 693   &mapping0_pack,
 694   &mapping0_unpack,
 695   &mapping0_look,
 696   &mapping0_copy_info,
 697   &mapping0_free_info,
 698   &mapping0_free_look,
 699   &mapping0_forward,
 700   &mapping0_inverse
 701 };