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vorbis_res0.c (24915B)


      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 1994-2010             *
      9 * by the Xiph.Org Foundation https://xiph.org/                     *
     10 *                                                                  *
     11 ********************************************************************
     12 
     13 function: residue backend 0, 1 and 2 implementation
     14 
     15 ********************************************************************/
     16 
     17 /* Slow, slow, slow, simpleminded and did I mention it was slow?  The
     18   encode/decode loops are coded for clarity and performance is not
     19   yet even a nagging little idea lurking in the shadows.  Oh and BTW,
     20   it's slow. */
     21 
     22 #include <stdlib.h>
     23 #include <string.h>
     24 #include <math.h>
     25 #include <ogg/ogg.h>
     26 #include "vorbis/codec.h"
     27 #include "codec_internal.h"
     28 #include "registry.h"
     29 #include "codebook.h"
     30 #include "misc.h"
     31 #include "os.h"
     32 
     33 #if defined(TRAIN_RES) || defined (TRAIN_RESAUX)
     34 #include <stdio.h>
     35 #endif
     36 
     37 typedef struct {
     38  vorbis_info_residue0 *info;
     39 
     40  int         parts;
     41  int         stages;
     42  codebook   *fullbooks;
     43  codebook   *phrasebook;
     44  codebook ***partbooks;
     45 
     46  int         partvals;
     47  int       **decodemap;
     48 
     49  long      postbits;
     50  long      phrasebits;
     51  long      frames;
     52 
     53 #if defined(TRAIN_RES) || defined(TRAIN_RESAUX)
     54  int        train_seq;
     55  long      *training_data[8][64];
     56  float      training_max[8][64];
     57  float      training_min[8][64];
     58  float     tmin;
     59  float     tmax;
     60  int       submap;
     61 #endif
     62 
     63 } vorbis_look_residue0;
     64 
     65 void res0_free_info(vorbis_info_residue *i){
     66  vorbis_info_residue0 *info=(vorbis_info_residue0 *)i;
     67  if(info){
     68    memset(info,0,sizeof(*info));
     69    _ogg_free(info);
     70  }
     71 }
     72 
     73 void res0_free_look(vorbis_look_residue *i){
     74  int j;
     75  if(i){
     76 
     77    vorbis_look_residue0 *look=(vorbis_look_residue0 *)i;
     78 
     79 #ifdef TRAIN_RES
     80    {
     81      int j,k,l;
     82      for(j=0;j<look->parts;j++){
     83        /*fprintf(stderr,"partition %d: ",j);*/
     84        for(k=0;k<8;k++)
     85          if(look->training_data[k][j]){
     86            char buffer[80];
     87            FILE *of;
     88            codebook *statebook=look->partbooks[j][k];
     89 
     90            /* long and short into the same bucket by current convention */
     91            sprintf(buffer,"res_sub%d_part%d_pass%d.vqd",look->submap,j,k);
     92            of=fopen(buffer,"a");
     93 
     94            for(l=0;l<statebook->entries;l++)
     95              fprintf(of,"%d:%ld\n",l,look->training_data[k][j][l]);
     96 
     97            fclose(of);
     98 
     99            /*fprintf(stderr,"%d(%.2f|%.2f) ",k,
    100              look->training_min[k][j],look->training_max[k][j]);*/
    101 
    102            _ogg_free(look->training_data[k][j]);
    103            look->training_data[k][j]=NULL;
    104          }
    105        /*fprintf(stderr,"\n");*/
    106      }
    107    }
    108    fprintf(stderr,"min/max residue: %g::%g\n",look->tmin,look->tmax);
    109 
    110    /*fprintf(stderr,"residue bit usage %f:%f (%f total)\n",
    111            (float)look->phrasebits/look->frames,
    112            (float)look->postbits/look->frames,
    113            (float)(look->postbits+look->phrasebits)/look->frames);*/
    114 #endif
    115 
    116 
    117    /*vorbis_info_residue0 *info=look->info;
    118 
    119    fprintf(stderr,
    120            "%ld frames encoded in %ld phrasebits and %ld residue bits "
    121            "(%g/frame) \n",look->frames,look->phrasebits,
    122            look->resbitsflat,
    123            (look->phrasebits+look->resbitsflat)/(float)look->frames);
    124 
    125    for(j=0;j<look->parts;j++){
    126      long acc=0;
    127      fprintf(stderr,"\t[%d] == ",j);
    128      for(k=0;k<look->stages;k++)
    129        if((info->secondstages[j]>>k)&1){
    130          fprintf(stderr,"%ld,",look->resbits[j][k]);
    131          acc+=look->resbits[j][k];
    132        }
    133 
    134      fprintf(stderr,":: (%ld vals) %1.2fbits/sample\n",look->resvals[j],
    135              acc?(float)acc/(look->resvals[j]*info->grouping):0);
    136    }
    137    fprintf(stderr,"\n");*/
    138 
    139    for(j=0;j<look->parts;j++)
    140      if(look->partbooks[j])_ogg_free(look->partbooks[j]);
    141    _ogg_free(look->partbooks);
    142    for(j=0;j<look->partvals;j++)
    143      _ogg_free(look->decodemap[j]);
    144    _ogg_free(look->decodemap);
    145 
    146    memset(look,0,sizeof(*look));
    147    _ogg_free(look);
    148  }
    149 }
    150 
    151 static int icount(unsigned int v){
    152  int ret=0;
    153  while(v){
    154    ret+=v&1;
    155    v>>=1;
    156  }
    157  return(ret);
    158 }
    159 
    160 
    161 void res0_pack(vorbis_info_residue *vr,oggpack_buffer *opb){
    162  vorbis_info_residue0 *info=(vorbis_info_residue0 *)vr;
    163  int j,acc=0;
    164  oggpack_write(opb,info->begin,24);
    165  oggpack_write(opb,info->end,24);
    166 
    167  oggpack_write(opb,info->grouping-1,24);  /* residue vectors to group and
    168                                             code with a partitioned book */
    169  oggpack_write(opb,info->partitions-1,6); /* possible partition choices */
    170  oggpack_write(opb,info->groupbook,8);  /* group huffman book */
    171 
    172  /* secondstages is a bitmask; as encoding progresses pass by pass, a
    173     bitmask of one indicates this partition class has bits to write
    174     this pass */
    175  for(j=0;j<info->partitions;j++){
    176    if(ov_ilog(info->secondstages[j])>3){
    177      /* yes, this is a minor hack due to not thinking ahead */
    178      oggpack_write(opb,info->secondstages[j],3);
    179      oggpack_write(opb,1,1);
    180      oggpack_write(opb,info->secondstages[j]>>3,5);
    181    }else
    182      oggpack_write(opb,info->secondstages[j],4); /* trailing zero */
    183    acc+=icount(info->secondstages[j]);
    184  }
    185  for(j=0;j<acc;j++)
    186    oggpack_write(opb,info->booklist[j],8);
    187 
    188 }
    189 
    190 /* vorbis_info is for range checking */
    191 vorbis_info_residue *res0_unpack(vorbis_info *vi,oggpack_buffer *opb){
    192  int j,acc=0;
    193  vorbis_info_residue0 *info=_ogg_calloc(1,sizeof(*info));
    194  codec_setup_info     *ci=vi->codec_setup;
    195 
    196  info->begin=oggpack_read(opb,24);
    197  info->end=oggpack_read(opb,24);
    198  info->grouping=oggpack_read(opb,24)+1;
    199  info->partitions=oggpack_read(opb,6)+1;
    200  info->groupbook=oggpack_read(opb,8);
    201 
    202  /* check for premature EOP */
    203  if(info->groupbook<0)goto errout;
    204 
    205  for(j=0;j<info->partitions;j++){
    206    int cascade=oggpack_read(opb,3);
    207    int cflag=oggpack_read(opb,1);
    208    if(cflag<0) goto errout;
    209    if(cflag){
    210      int c=oggpack_read(opb,5);
    211      if(c<0) goto errout;
    212      cascade|=(c<<3);
    213    }
    214    info->secondstages[j]=cascade;
    215 
    216    acc+=icount(cascade);
    217  }
    218  for(j=0;j<acc;j++){
    219    int book=oggpack_read(opb,8);
    220    if(book<0) goto errout;
    221    info->booklist[j]=book;
    222  }
    223 
    224  if(info->groupbook>=ci->books)goto errout;
    225  for(j=0;j<acc;j++){
    226    if(info->booklist[j]>=ci->books)goto errout;
    227    if(ci->book_param[info->booklist[j]]->maptype==0)goto errout;
    228  }
    229 
    230  /* verify the phrasebook is not specifying an impossible or
    231     inconsistent partitioning scheme. */
    232  /* modify the phrasebook ranging check from r16327; an early beta
    233     encoder had a bug where it used an oversized phrasebook by
    234     accident.  These files should continue to be playable, but don't
    235     allow an exploit */
    236  {
    237    int entries = ci->book_param[info->groupbook]->entries;
    238    int dim = ci->book_param[info->groupbook]->dim;
    239    int partvals = 1;
    240    if (dim<1) goto errout;
    241    while(dim>0){
    242      partvals *= info->partitions;
    243      if(partvals > entries) goto errout;
    244      dim--;
    245    }
    246    info->partvals = partvals;
    247  }
    248 
    249  return(info);
    250 errout:
    251  res0_free_info(info);
    252  return(NULL);
    253 }
    254 
    255 vorbis_look_residue *res0_look(vorbis_dsp_state *vd,
    256                               vorbis_info_residue *vr){
    257  vorbis_info_residue0 *info=(vorbis_info_residue0 *)vr;
    258  vorbis_look_residue0 *look=_ogg_calloc(1,sizeof(*look));
    259  codec_setup_info     *ci=vd->vi->codec_setup;
    260 
    261  int j,k,acc=0;
    262  int dim;
    263  int maxstage=0;
    264  look->info=info;
    265 
    266  look->parts=info->partitions;
    267  look->fullbooks=ci->fullbooks;
    268  look->phrasebook=ci->fullbooks+info->groupbook;
    269  dim=look->phrasebook->dim;
    270 
    271  look->partbooks=_ogg_calloc(look->parts,sizeof(*look->partbooks));
    272 
    273  for(j=0;j<look->parts;j++){
    274    int stages=ov_ilog(info->secondstages[j]);
    275    if(stages){
    276      if(stages>maxstage)maxstage=stages;
    277      look->partbooks[j]=_ogg_calloc(stages,sizeof(*look->partbooks[j]));
    278      for(k=0;k<stages;k++)
    279        if(info->secondstages[j]&(1<<k)){
    280          look->partbooks[j][k]=ci->fullbooks+info->booklist[acc++];
    281 #ifdef TRAIN_RES
    282          look->training_data[k][j]=_ogg_calloc(look->partbooks[j][k]->entries,
    283                                           sizeof(***look->training_data));
    284 #endif
    285        }
    286    }
    287  }
    288 
    289  look->partvals=1;
    290  for(j=0;j<dim;j++)
    291      look->partvals*=look->parts;
    292 
    293  look->stages=maxstage;
    294  look->decodemap=_ogg_malloc(look->partvals*sizeof(*look->decodemap));
    295  for(j=0;j<look->partvals;j++){
    296    long val=j;
    297    long mult=look->partvals/look->parts;
    298    look->decodemap[j]=_ogg_malloc(dim*sizeof(*look->decodemap[j]));
    299    for(k=0;k<dim;k++){
    300      long deco=val/mult;
    301      val-=deco*mult;
    302      mult/=look->parts;
    303      look->decodemap[j][k]=deco;
    304    }
    305  }
    306 #if defined(TRAIN_RES) || defined (TRAIN_RESAUX)
    307  {
    308    static int train_seq=0;
    309    look->train_seq=train_seq++;
    310  }
    311 #endif
    312  return(look);
    313 }
    314 
    315 /* break an abstraction and copy some code for performance purposes */
    316 static int local_book_besterror(codebook *book,int *a){
    317  int dim=book->dim;
    318  int i,j,o;
    319  int minval=book->minval;
    320  int del=book->delta;
    321  int qv=book->quantvals;
    322  int ze=(qv>>1);
    323  int index=0;
    324  /* assumes integer/centered encoder codebook maptype 1 no more than dim 8 */
    325  int p[8]={0,0,0,0,0,0,0,0};
    326 
    327  if(del!=1){
    328    for(i=0,o=dim;i<dim;i++){
    329      int v = (a[--o]-minval+(del>>1))/del;
    330      int m = (v<ze ? ((ze-v)<<1)-1 : ((v-ze)<<1));
    331      index = index*qv+ (m<0?0:(m>=qv?qv-1:m));
    332      p[o]=v*del+minval;
    333    }
    334  }else{
    335    for(i=0,o=dim;i<dim;i++){
    336      int v = a[--o]-minval;
    337      int m = (v<ze ? ((ze-v)<<1)-1 : ((v-ze)<<1));
    338      index = index*qv+ (m<0?0:(m>=qv?qv-1:m));
    339      p[o]=v*del+minval;
    340    }
    341  }
    342 
    343  if(book->c->lengthlist[index]<=0){
    344    const static_codebook *c=book->c;
    345    int best=-1;
    346    /* assumes integer/centered encoder codebook maptype 1 no more than dim 8 */
    347    int e[8]={0,0,0,0,0,0,0,0};
    348    int maxval = book->minval + book->delta*(book->quantvals-1);
    349    for(i=0;i<book->entries;i++){
    350      if(c->lengthlist[i]>0){
    351        int this=0;
    352        for(j=0;j<dim;j++){
    353          int val=(e[j]-a[j]);
    354          this+=val*val;
    355        }
    356        if(best==-1 || this<best){
    357          memcpy(p,e,sizeof(p));
    358          best=this;
    359          index=i;
    360        }
    361      }
    362      /* assumes the value patterning created by the tools in vq/ */
    363      j=0;
    364      while(e[j]>=maxval)
    365        e[j++]=0;
    366      if(e[j]>=0)
    367        e[j]+=book->delta;
    368      e[j]= -e[j];
    369    }
    370  }
    371 
    372  if(index>-1){
    373    for(i=0;i<dim;i++)
    374      *a++ -= p[i];
    375  }
    376 
    377  return(index);
    378 }
    379 
    380 #ifdef TRAIN_RES
    381 static int _encodepart(oggpack_buffer *opb,int *vec, int n,
    382                       codebook *book,long *acc){
    383 #else
    384 static int _encodepart(oggpack_buffer *opb,int *vec, int n,
    385                       codebook *book){
    386 #endif
    387  int i,bits=0;
    388  int dim=book->dim;
    389  int step=n/dim;
    390 
    391  for(i=0;i<step;i++){
    392    int entry=local_book_besterror(book,vec+i*dim);
    393 
    394 #ifdef TRAIN_RES
    395    if(entry>=0)
    396      acc[entry]++;
    397 #endif
    398 
    399    bits+=vorbis_book_encode(book,entry,opb);
    400 
    401  }
    402 
    403  return(bits);
    404 }
    405 
    406 static long **_01class(vorbis_block *vb,vorbis_look_residue *vl,
    407                       int **in,int ch){
    408  long i,j,k;
    409  vorbis_look_residue0 *look=(vorbis_look_residue0 *)vl;
    410  vorbis_info_residue0 *info=look->info;
    411 
    412  /* move all this setup out later */
    413  int samples_per_partition=info->grouping;
    414  int possible_partitions=info->partitions;
    415  int n=info->end-info->begin;
    416 
    417  int partvals=n/samples_per_partition;
    418  long **partword=_vorbis_block_alloc(vb,ch*sizeof(*partword));
    419  float scale=100./samples_per_partition;
    420 
    421  /* we find the partition type for each partition of each
    422     channel.  We'll go back and do the interleaved encoding in a
    423     bit.  For now, clarity */
    424 
    425  for(i=0;i<ch;i++){
    426    partword[i]=_vorbis_block_alloc(vb,n/samples_per_partition*sizeof(*partword[i]));
    427    memset(partword[i],0,n/samples_per_partition*sizeof(*partword[i]));
    428  }
    429 
    430  for(i=0;i<partvals;i++){
    431    int offset=i*samples_per_partition+info->begin;
    432    for(j=0;j<ch;j++){
    433      int max=0;
    434      int ent=0;
    435      for(k=0;k<samples_per_partition;k++){
    436        if(abs(in[j][offset+k])>max)max=abs(in[j][offset+k]);
    437        ent+=abs(in[j][offset+k]);
    438      }
    439      ent*=scale;
    440 
    441      for(k=0;k<possible_partitions-1;k++)
    442        if(max<=info->classmetric1[k] &&
    443           (info->classmetric2[k]<0 || ent<info->classmetric2[k]))
    444          break;
    445 
    446      partword[j][i]=k;
    447    }
    448  }
    449 
    450 #ifdef TRAIN_RESAUX
    451  {
    452    FILE *of;
    453    char buffer[80];
    454 
    455    for(i=0;i<ch;i++){
    456      sprintf(buffer,"resaux_%d.vqd",look->train_seq);
    457      of=fopen(buffer,"a");
    458      for(j=0;j<partvals;j++)
    459        fprintf(of,"%ld, ",partword[i][j]);
    460      fprintf(of,"\n");
    461      fclose(of);
    462    }
    463  }
    464 #endif
    465  look->frames++;
    466 
    467  return(partword);
    468 }
    469 
    470 /* designed for stereo or other modes where the partition size is an
    471   integer multiple of the number of channels encoded in the current
    472   submap */
    473 static long **_2class(vorbis_block *vb,vorbis_look_residue *vl,int **in,
    474                      int ch){
    475  long i,j,k,l;
    476  vorbis_look_residue0 *look=(vorbis_look_residue0 *)vl;
    477  vorbis_info_residue0 *info=look->info;
    478 
    479  /* move all this setup out later */
    480  int samples_per_partition=info->grouping;
    481  int possible_partitions=info->partitions;
    482  int n=info->end-info->begin;
    483 
    484  int partvals=n/samples_per_partition;
    485  long **partword=_vorbis_block_alloc(vb,sizeof(*partword));
    486 
    487 #if defined(TRAIN_RES) || defined (TRAIN_RESAUX)
    488  FILE *of;
    489  char buffer[80];
    490 #endif
    491 
    492  partword[0]=_vorbis_block_alloc(vb,partvals*sizeof(*partword[0]));
    493  memset(partword[0],0,partvals*sizeof(*partword[0]));
    494 
    495  for(i=0,l=info->begin/ch;i<partvals;i++){
    496    int magmax=0;
    497    int angmax=0;
    498    for(j=0;j<samples_per_partition;j+=ch){
    499      if(abs(in[0][l])>magmax)magmax=abs(in[0][l]);
    500      for(k=1;k<ch;k++)
    501        if(abs(in[k][l])>angmax)angmax=abs(in[k][l]);
    502      l++;
    503    }
    504 
    505    for(j=0;j<possible_partitions-1;j++)
    506      if(magmax<=info->classmetric1[j] &&
    507         angmax<=info->classmetric2[j])
    508        break;
    509 
    510    partword[0][i]=j;
    511 
    512  }
    513 
    514 #ifdef TRAIN_RESAUX
    515  sprintf(buffer,"resaux_%d.vqd",look->train_seq);
    516  of=fopen(buffer,"a");
    517  for(i=0;i<partvals;i++)
    518    fprintf(of,"%ld, ",partword[0][i]);
    519  fprintf(of,"\n");
    520  fclose(of);
    521 #endif
    522 
    523  look->frames++;
    524 
    525  return(partword);
    526 }
    527 
    528 static int _01forward(oggpack_buffer *opb,
    529                      vorbis_look_residue *vl,
    530                      int **in,int ch,
    531                      long **partword,
    532 #ifdef TRAIN_RES
    533                      int (*encode)(oggpack_buffer *,int *,int,
    534                                    codebook *,long *),
    535                      int submap
    536 #else
    537                      int (*encode)(oggpack_buffer *,int *,int,
    538                                    codebook *)
    539 #endif
    540 ){
    541  long i,j,k,s;
    542  vorbis_look_residue0 *look=(vorbis_look_residue0 *)vl;
    543  vorbis_info_residue0 *info=look->info;
    544 
    545 #ifdef TRAIN_RES
    546  look->submap=submap;
    547 #endif
    548 
    549  /* move all this setup out later */
    550  int samples_per_partition=info->grouping;
    551  int possible_partitions=info->partitions;
    552  int partitions_per_word=look->phrasebook->dim;
    553  int n=info->end-info->begin;
    554 
    555  int partvals=n/samples_per_partition;
    556  long resbits[128];
    557  long resvals[128];
    558 
    559 #ifdef TRAIN_RES
    560  for(i=0;i<ch;i++)
    561    for(j=info->begin;j<info->end;j++){
    562      if(in[i][j]>look->tmax)look->tmax=in[i][j];
    563      if(in[i][j]<look->tmin)look->tmin=in[i][j];
    564    }
    565 #endif
    566 
    567  memset(resbits,0,sizeof(resbits));
    568  memset(resvals,0,sizeof(resvals));
    569 
    570  /* we code the partition words for each channel, then the residual
    571     words for a partition per channel until we've written all the
    572     residual words for that partition word.  Then write the next
    573     partition channel words... */
    574 
    575  for(s=0;s<look->stages;s++){
    576 
    577    for(i=0;i<partvals;){
    578 
    579      /* first we encode a partition codeword for each channel */
    580      if(s==0){
    581        for(j=0;j<ch;j++){
    582          long val=partword[j][i];
    583          for(k=1;k<partitions_per_word;k++){
    584            val*=possible_partitions;
    585            if(i+k<partvals)
    586              val+=partword[j][i+k];
    587          }
    588 
    589          /* training hack */
    590          if(val<look->phrasebook->entries)
    591            look->phrasebits+=vorbis_book_encode(look->phrasebook,val,opb);
    592 #if 0 /*def TRAIN_RES*/
    593          else
    594            fprintf(stderr,"!");
    595 #endif
    596 
    597        }
    598      }
    599 
    600      /* now we encode interleaved residual values for the partitions */
    601      for(k=0;k<partitions_per_word && i<partvals;k++,i++){
    602        long offset=i*samples_per_partition+info->begin;
    603 
    604        for(j=0;j<ch;j++){
    605          if(s==0)resvals[partword[j][i]]+=samples_per_partition;
    606          if(info->secondstages[partword[j][i]]&(1<<s)){
    607            codebook *statebook=look->partbooks[partword[j][i]][s];
    608            if(statebook){
    609              int ret;
    610 #ifdef TRAIN_RES
    611              long *accumulator=NULL;
    612              accumulator=look->training_data[s][partword[j][i]];
    613              {
    614                int l;
    615                int *samples=in[j]+offset;
    616                for(l=0;l<samples_per_partition;l++){
    617                  if(samples[l]<look->training_min[s][partword[j][i]])
    618                    look->training_min[s][partword[j][i]]=samples[l];
    619                  if(samples[l]>look->training_max[s][partword[j][i]])
    620                    look->training_max[s][partword[j][i]]=samples[l];
    621                }
    622              }
    623              ret=encode(opb,in[j]+offset,samples_per_partition,
    624                         statebook,accumulator);
    625 #else
    626              ret=encode(opb,in[j]+offset,samples_per_partition,
    627                         statebook);
    628 #endif
    629 
    630              look->postbits+=ret;
    631              resbits[partword[j][i]]+=ret;
    632            }
    633          }
    634        }
    635      }
    636    }
    637  }
    638 
    639  return(0);
    640 }
    641 
    642 /* a truncated packet here just means 'stop working'; it's not an error */
    643 static int _01inverse(vorbis_block *vb,vorbis_look_residue *vl,
    644                      float **in,int ch,
    645                      long (*decodepart)(codebook *, float *,
    646                                         oggpack_buffer *,int)){
    647 
    648  long i,j,k,l,s;
    649  vorbis_look_residue0 *look=(vorbis_look_residue0 *)vl;
    650  vorbis_info_residue0 *info=look->info;
    651 
    652  /* move all this setup out later */
    653  int samples_per_partition=info->grouping;
    654  int partitions_per_word=look->phrasebook->dim;
    655  int max=vb->pcmend>>1;
    656  int end=(info->end<max?info->end:max);
    657  int n=end-info->begin;
    658 
    659  if(n>0){
    660    int partvals=n/samples_per_partition;
    661    int partwords=(partvals+partitions_per_word-1)/partitions_per_word;
    662    int ***partword=alloca(ch*sizeof(*partword));
    663 
    664    for(j=0;j<ch;j++)
    665      partword[j]=_vorbis_block_alloc(vb,partwords*sizeof(*partword[j]));
    666 
    667    for(s=0;s<look->stages;s++){
    668 
    669      /* each loop decodes on partition codeword containing
    670         partitions_per_word partitions */
    671      for(i=0,l=0;i<partvals;l++){
    672        if(s==0){
    673          /* fetch the partition word for each channel */
    674          for(j=0;j<ch;j++){
    675            int temp=vorbis_book_decode(look->phrasebook,&vb->opb);
    676 
    677            if(temp==-1 || temp>=info->partvals)goto eopbreak;
    678            partword[j][l]=look->decodemap[temp];
    679            if(partword[j][l]==NULL)goto errout;
    680          }
    681        }
    682 
    683        /* now we decode residual values for the partitions */
    684        for(k=0;k<partitions_per_word && i<partvals;k++,i++)
    685          for(j=0;j<ch;j++){
    686            long offset=info->begin+i*samples_per_partition;
    687            if(info->secondstages[partword[j][l][k]]&(1<<s)){
    688              codebook *stagebook=look->partbooks[partword[j][l][k]][s];
    689              if(stagebook){
    690                if(decodepart(stagebook,in[j]+offset,&vb->opb,
    691                              samples_per_partition)==-1)goto eopbreak;
    692              }
    693            }
    694          }
    695      }
    696    }
    697  }
    698 errout:
    699 eopbreak:
    700  return(0);
    701 }
    702 
    703 int res0_inverse(vorbis_block *vb,vorbis_look_residue *vl,
    704                 float **in,int *nonzero,int ch){
    705  int i,used=0;
    706  for(i=0;i<ch;i++)
    707    if(nonzero[i])
    708      in[used++]=in[i];
    709  if(used)
    710    return(_01inverse(vb,vl,in,used,vorbis_book_decodevs_add));
    711  else
    712    return(0);
    713 }
    714 
    715 int res1_forward(oggpack_buffer *opb,vorbis_block *vb,vorbis_look_residue *vl,
    716                 int **in,int *nonzero,int ch, long **partword, int submap){
    717  int i,used=0;
    718  (void)vb;
    719  for(i=0;i<ch;i++)
    720    if(nonzero[i])
    721      in[used++]=in[i];
    722 
    723  if(used){
    724 #ifdef TRAIN_RES
    725    return _01forward(opb,vl,in,used,partword,_encodepart,submap);
    726 #else
    727    (void)submap;
    728    return _01forward(opb,vl,in,used,partword,_encodepart);
    729 #endif
    730  }else{
    731    return(0);
    732  }
    733 }
    734 
    735 long **res1_class(vorbis_block *vb,vorbis_look_residue *vl,
    736                  int **in,int *nonzero,int ch){
    737  int i,used=0;
    738  for(i=0;i<ch;i++)
    739    if(nonzero[i])
    740      in[used++]=in[i];
    741  if(used)
    742    return(_01class(vb,vl,in,used));
    743  else
    744    return(0);
    745 }
    746 
    747 int res1_inverse(vorbis_block *vb,vorbis_look_residue *vl,
    748                 float **in,int *nonzero,int ch){
    749  int i,used=0;
    750  for(i=0;i<ch;i++)
    751    if(nonzero[i])
    752      in[used++]=in[i];
    753  if(used)
    754    return(_01inverse(vb,vl,in,used,vorbis_book_decodev_add));
    755  else
    756    return(0);
    757 }
    758 
    759 long **res2_class(vorbis_block *vb,vorbis_look_residue *vl,
    760                  int **in,int *nonzero,int ch){
    761  int i,used=0;
    762  for(i=0;i<ch;i++)
    763    if(nonzero[i])used++;
    764  if(used)
    765    return(_2class(vb,vl,in,ch));
    766  else
    767    return(0);
    768 }
    769 
    770 /* res2 is slightly more different; all the channels are interleaved
    771   into a single vector and encoded. */
    772 
    773 int res2_forward(oggpack_buffer *opb,
    774                 vorbis_block *vb,vorbis_look_residue *vl,
    775                 int **in,int *nonzero,int ch, long **partword,int submap){
    776  long i,j,k,n=vb->pcmend/2,used=0;
    777 
    778  /* don't duplicate the code; use a working vector hack for now and
    779     reshape ourselves into a single channel res1 */
    780  /* ugly; reallocs for each coupling pass :-( */
    781  int *work=_vorbis_block_alloc(vb,ch*n*sizeof(*work));
    782  for(i=0;i<ch;i++){
    783    int *pcm=in[i];
    784    if(nonzero[i])used++;
    785    for(j=0,k=i;j<n;j++,k+=ch)
    786      work[k]=pcm[j];
    787  }
    788 
    789  if(used){
    790 #ifdef TRAIN_RES
    791    return _01forward(opb,vl,&work,1,partword,_encodepart,submap);
    792 #else
    793    (void)submap;
    794    return _01forward(opb,vl,&work,1,partword,_encodepart);
    795 #endif
    796  }else{
    797    return(0);
    798  }
    799 }
    800 
    801 /* duplicate code here as speed is somewhat more important */
    802 int res2_inverse(vorbis_block *vb,vorbis_look_residue *vl,
    803                 float **in,int *nonzero,int ch){
    804  long i,k,l,s;
    805  vorbis_look_residue0 *look=(vorbis_look_residue0 *)vl;
    806  vorbis_info_residue0 *info=look->info;
    807 
    808  /* move all this setup out later */
    809  int samples_per_partition=info->grouping;
    810  int partitions_per_word=look->phrasebook->dim;
    811  int max=(vb->pcmend*ch)>>1;
    812  int end=(info->end<max?info->end:max);
    813  int n=end-info->begin;
    814 
    815  if(n>0){
    816    int partvals=n/samples_per_partition;
    817    int partwords=(partvals+partitions_per_word-1)/partitions_per_word;
    818    int **partword=_vorbis_block_alloc(vb,partwords*sizeof(*partword));
    819 
    820    for(i=0;i<ch;i++)if(nonzero[i])break;
    821    if(i==ch)return(0); /* no nonzero vectors */
    822 
    823    for(s=0;s<look->stages;s++){
    824      for(i=0,l=0;i<partvals;l++){
    825 
    826        if(s==0){
    827          /* fetch the partition word */
    828          int temp=vorbis_book_decode(look->phrasebook,&vb->opb);
    829          if(temp==-1 || temp>=info->partvals)goto eopbreak;
    830          partword[l]=look->decodemap[temp];
    831          if(partword[l]==NULL)goto errout;
    832        }
    833 
    834        /* now we decode residual values for the partitions */
    835        for(k=0;k<partitions_per_word && i<partvals;k++,i++)
    836          if(info->secondstages[partword[l][k]]&(1<<s)){
    837            codebook *stagebook=look->partbooks[partword[l][k]][s];
    838 
    839            if(stagebook){
    840              if(vorbis_book_decodevv_add(stagebook,in,
    841                                          i*samples_per_partition+info->begin,ch,
    842                                          &vb->opb,samples_per_partition)==-1)
    843                goto eopbreak;
    844            }
    845          }
    846      }
    847    }
    848  }
    849 errout:
    850 eopbreak:
    851  return(0);
    852 }
    853 
    854 
    855 const vorbis_func_residue residue0_exportbundle={
    856  NULL,
    857  &res0_unpack,
    858  &res0_look,
    859  &res0_free_info,
    860  &res0_free_look,
    861  NULL,
    862  NULL,
    863  &res0_inverse
    864 };
    865 
    866 const vorbis_func_residue residue1_exportbundle={
    867  &res0_pack,
    868  &res0_unpack,
    869  &res0_look,
    870  &res0_free_info,
    871  &res0_free_look,
    872  &res1_class,
    873  &res1_forward,
    874  &res1_inverse
    875 };
    876 
    877 const vorbis_func_residue residue2_exportbundle={
    878  &res0_pack,
    879  &res0_unpack,
    880  &res0_look,
    881  &res0_free_info,
    882  &res0_free_look,
    883  &res2_class,
    884  &res2_forward,
    885  &res2_inverse
    886 };