• res0.c
  • /********************************************************************
     *                                                                  *
     * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
     * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
     * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
     * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
     *                                                                  *
     * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2010             *
     * by the Xiph.Org Foundation https://xiph.org/                     *
     *                                                                  *
     ********************************************************************
    
     function: residue backend 0, 1 and 2 implementation
    
     ********************************************************************/
    
    /* Slow, slow, slow, simpleminded and did I mention it was slow?  The
       encode/decode loops are coded for clarity and performance is not
       yet even a nagging little idea lurking in the shadows.  Oh and BTW,
       it's slow. */
    
    #include <stdlib.h>
    #include <string.h>
    #include <math.h>
    #include <ogg/ogg.h>
    #include "vorbis/codec.h"
    #include "codec_internal.h"
    #include "registry.h"
    #include "codebook.h"
    #include "misc.h"
    #include "os.h"
    
    #if defined(TRAIN_RES) || defined (TRAIN_RESAUX)
    #include <stdio.h>
    #endif
    
    typedef struct {
      vorbis_info_residue0 *info;
    
      int         parts;
      int         stages;
      codebook   *fullbooks;
      codebook   *phrasebook;
      codebook ***partbooks;
    
      int         partvals;
      int       **decodemap;
    
      long      postbits;
      long      phrasebits;
      long      frames;
    
    #if defined(TRAIN_RES) || defined(TRAIN_RESAUX)
      int        train_seq;
      long      *training_data[8][64];
      float      training_max[8][64];
      float      training_min[8][64];
      float     tmin;
      float     tmax;
      int       submap;
    #endif
    
    } vorbis_look_residue0;
    
    void res0_free_info(vorbis_info_residue *i){
      vorbis_info_residue0 *info=(vorbis_info_residue0 *)i;
      if(info){
        memset(info,0,sizeof(*info));
        _ogg_free(info);
      }
    }
    
    void res0_free_look(vorbis_look_residue *i){
      int j;
      if(i){
    
        vorbis_look_residue0 *look=(vorbis_look_residue0 *)i;
    
    #ifdef TRAIN_RES
        {
          int j,k,l;
          for(j=0;j<look->parts;j++){
            /*fprintf(stderr,"partition %d: ",j);*/
            for(k=0;k<8;k++)
              if(look->training_data[k][j]){
                char buffer[80];
                FILE *of;
                codebook *statebook=look->partbooks[j][k];
    
                /* long and short into the same bucket by current convention */
                sprintf(buffer,"res_sub%d_part%d_pass%d.vqd",look->submap,j,k);
                of=fopen(buffer,"a");
    
                for(l=0;l<statebook->entries;l++)
                  fprintf(of,"%d:%ld\n",l,look->training_data[k][j][l]);
    
                fclose(of);
    
                /*fprintf(stderr,"%d(%.2f|%.2f) ",k,
                  look->training_min[k][j],look->training_max[k][j]);*/
    
                _ogg_free(look->training_data[k][j]);
                look->training_data[k][j]=NULL;
              }
            /*fprintf(stderr,"\n");*/
          }
        }
        fprintf(stderr,"min/max residue: %g::%g\n",look->tmin,look->tmax);
    
        /*fprintf(stderr,"residue bit usage %f:%f (%f total)\n",
                (float)look->phrasebits/look->frames,
                (float)look->postbits/look->frames,
                (float)(look->postbits+look->phrasebits)/look->frames);*/
    #endif
    
    
        /*vorbis_info_residue0 *info=look->info;
    
        fprintf(stderr,
                "%ld frames encoded in %ld phrasebits and %ld residue bits "
                "(%g/frame) \n",look->frames,look->phrasebits,
                look->resbitsflat,
                (look->phrasebits+look->resbitsflat)/(float)look->frames);
    
        for(j=0;j<look->parts;j++){
          long acc=0;
          fprintf(stderr,"\t[%d] == ",j);
          for(k=0;k<look->stages;k++)
            if((info->secondstages[j]>>k)&1){
              fprintf(stderr,"%ld,",look->resbits[j][k]);
              acc+=look->resbits[j][k];
            }
    
          fprintf(stderr,":: (%ld vals) %1.2fbits/sample\n",look->resvals[j],
                  acc?(float)acc/(look->resvals[j]*info->grouping):0);
        }
        fprintf(stderr,"\n");*/
    
        for(j=0;j<look->parts;j++)
          if(look->partbooks[j])_ogg_free(look->partbooks[j]);
        _ogg_free(look->partbooks);
        for(j=0;j<look->partvals;j++)
          _ogg_free(look->decodemap[j]);
        _ogg_free(look->decodemap);
    
        memset(look,0,sizeof(*look));
        _ogg_free(look);
      }
    }
    
    static int icount(unsigned int v){
      int ret=0;
      while(v){
        ret+=v&1;
        v>>=1;
      }
      return(ret);
    }
    
    
    void res0_pack(vorbis_info_residue *vr,oggpack_buffer *opb){
      vorbis_info_residue0 *info=(vorbis_info_residue0 *)vr;
      int j,acc=0;
      oggpack_write(opb,info->begin,24);
      oggpack_write(opb,info->end,24);
    
      oggpack_write(opb,info->grouping-1,24);  /* residue vectors to group and
                                                 code with a partitioned book */
      oggpack_write(opb,info->partitions-1,6); /* possible partition choices */
      oggpack_write(opb,info->groupbook,8);  /* group huffman book */
    
      /* secondstages is a bitmask; as encoding progresses pass by pass, a
         bitmask of one indicates this partition class has bits to write
         this pass */
      for(j=0;j<info->partitions;j++){
        if(ov_ilog(info->secondstages[j])>3){
          /* yes, this is a minor hack due to not thinking ahead */
          oggpack_write(opb,info->secondstages[j],3);
          oggpack_write(opb,1,1);
          oggpack_write(opb,info->secondstages[j]>>3,5);
        }else
          oggpack_write(opb,info->secondstages[j],4); /* trailing zero */
        acc+=icount(info->secondstages[j]);
      }
      for(j=0;j<acc;j++)
        oggpack_write(opb,info->booklist[j],8);
    
    }
    
    /* vorbis_info is for range checking */
    vorbis_info_residue *res0_unpack(vorbis_info *vi,oggpack_buffer *opb){
      int j,acc=0;
      vorbis_info_residue0 *info=_ogg_calloc(1,sizeof(*info));
      codec_setup_info     *ci=vi->codec_setup;
    
      info->begin=oggpack_read(opb,24);
      info->end=oggpack_read(opb,24);
      info->grouping=oggpack_read(opb,24)+1;
      info->partitions=oggpack_read(opb,6)+1;
      info->groupbook=oggpack_read(opb,8);
    
      /* check for premature EOP */
      if(info->groupbook<0)goto errout;
    
      for(j=0;j<info->partitions;j++){
        int cascade=oggpack_read(opb,3);
        int cflag=oggpack_read(opb,1);
        if(cflag<0) goto errout;
        if(cflag){
          int c=oggpack_read(opb,5);
          if(c<0) goto errout;
          cascade|=(c<<3);
        }
        info->secondstages[j]=cascade;
    
        acc+=icount(cascade);
      }
      for(j=0;j<acc;j++){
        int book=oggpack_read(opb,8);
        if(book<0) goto errout;
        info->booklist[j]=book;
      }
    
      if(info->groupbook>=ci->books)goto errout;
      for(j=0;j<acc;j++){
        if(info->booklist[j]>=ci->books)goto errout;
        if(ci->book_param[info->booklist[j]]->maptype==0)goto errout;
      }
    
      /* verify the phrasebook is not specifying an impossible or
         inconsistent partitioning scheme. */
      /* modify the phrasebook ranging check from r16327; an early beta
         encoder had a bug where it used an oversized phrasebook by
         accident.  These files should continue to be playable, but don't
         allow an exploit */
      {
        int entries = ci->book_param[info->groupbook]->entries;
        int dim = ci->book_param[info->groupbook]->dim;
        int partvals = 1;
        if (dim<1) goto errout;
        while(dim>0){
          partvals *= info->partitions;
          if(partvals > entries) goto errout;
          dim--;
        }
        info->partvals = partvals;
      }
    
      return(info);
     errout:
      res0_free_info(info);
      return(NULL);
    }
    
    vorbis_look_residue *res0_look(vorbis_dsp_state *vd,
                                   vorbis_info_residue *vr){
      vorbis_info_residue0 *info=(vorbis_info_residue0 *)vr;
      vorbis_look_residue0 *look=_ogg_calloc(1,sizeof(*look));
      codec_setup_info     *ci=vd->vi->codec_setup;
    
      int j,k,acc=0;
      int dim;
      int maxstage=0;
      look->info=info;
    
      look->parts=info->partitions;
      look->fullbooks=ci->fullbooks;
      look->phrasebook=ci->fullbooks+info->groupbook;
      dim=look->phrasebook->dim;
    
      look->partbooks=_ogg_calloc(look->parts,sizeof(*look->partbooks));
    
      for(j=0;j<look->parts;j++){
        int stages=ov_ilog(info->secondstages[j]);
        if(stages){
          if(stages>maxstage)maxstage=stages;
          look->partbooks[j]=_ogg_calloc(stages,sizeof(*look->partbooks[j]));
          for(k=0;k<stages;k++)
            if(info->secondstages[j]&(1<<k)){
              look->partbooks[j][k]=ci->fullbooks+info->booklist[acc++];
    #ifdef TRAIN_RES
              look->training_data[k][j]=_ogg_calloc(look->partbooks[j][k]->entries,
                                               sizeof(***look->training_data));
    #endif
            }
        }
      }
    
      look->partvals=1;
      for(j=0;j<dim;j++)
          look->partvals*=look->parts;
    
      look->stages=maxstage;
      look->decodemap=_ogg_malloc(look->partvals*sizeof(*look->decodemap));
      for(j=0;j<look->partvals;j++){
        long val=j;
        long mult=look->partvals/look->parts;
        look->decodemap[j]=_ogg_malloc(dim*sizeof(*look->decodemap[j]));
        for(k=0;k<dim;k++){
          long deco=val/mult;
          val-=deco*mult;
          mult/=look->parts;
          look->decodemap[j][k]=deco;
        }
      }
    #if defined(TRAIN_RES) || defined (TRAIN_RESAUX)
      {
        static int train_seq=0;
        look->train_seq=train_seq++;
      }
    #endif
      return(look);
    }
    
    /* break an abstraction and copy some code for performance purposes */
    static int local_book_besterror(codebook *book,int *a){
      int dim=book->dim;
      int i,j,o;
      int minval=book->minval;
      int del=book->delta;
      int qv=book->quantvals;
      int ze=(qv>>1);
      int index=0;
      /* assumes integer/centered encoder codebook maptype 1 no more than dim 8 */
      int p[8]={0,0,0,0,0,0,0,0};
    
      if(del!=1){
        for(i=0,o=dim;i<dim;i++){
          int v = (a[--o]-minval+(del>>1))/del;
          int m = (v<ze ? ((ze-v)<<1)-1 : ((v-ze)<<1));
          index = index*qv+ (m<0?0:(m>=qv?qv-1:m));
          p[o]=v*del+minval;
        }
      }else{
        for(i=0,o=dim;i<dim;i++){
          int v = a[--o]-minval;
          int m = (v<ze ? ((ze-v)<<1)-1 : ((v-ze)<<1));
          index = index*qv+ (m<0?0:(m>=qv?qv-1:m));
          p[o]=v*del+minval;
        }
      }
    
      if(book->c->lengthlist[index]<=0){
        const static_codebook *c=book->c;
        int best=-1;
        /* assumes integer/centered encoder codebook maptype 1 no more than dim 8 */
        int e[8]={0,0,0,0,0,0,0,0};
        int maxval = book->minval + book->delta*(book->quantvals-1);
        for(i=0;i<book->entries;i++){
          if(c->lengthlist[i]>0){
            int this=0;
            for(j=0;j<dim;j++){
              int val=(e[j]-a[j]);
              this+=val*val;
            }
            if(best==-1 || this<best){
              memcpy(p,e,sizeof(p));
              best=this;
              index=i;
            }
          }
          /* assumes the value patterning created by the tools in vq/ */
          j=0;
          while(e[j]>=maxval)
            e[j++]=0;
          if(e[j]>=0)
            e[j]+=book->delta;
          e[j]= -e[j];
        }
      }
    
      if(index>-1){
        for(i=0;i<dim;i++)
          *a++ -= p[i];
      }
    
      return(index);
    }
    
    #ifdef TRAIN_RES
    static int _encodepart(oggpack_buffer *opb,int *vec, int n,
                           codebook *book,long *acc){
    #else
    static int _encodepart(oggpack_buffer *opb,int *vec, int n,
                           codebook *book){
    #endif
      int i,bits=0;
      int dim=book->dim;
      int step=n/dim;
    
      for(i=0;i<step;i++){
        int entry=local_book_besterror(book,vec+i*dim);
    
    #ifdef TRAIN_RES
        if(entry>=0)
          acc[entry]++;
    #endif
    
        bits+=vorbis_book_encode(book,entry,opb);
    
      }
    
      return(bits);
    }
    
    static long **_01class(vorbis_block *vb,vorbis_look_residue *vl,
                           int **in,int ch){
      long i,j,k;
      vorbis_look_residue0 *look=(vorbis_look_residue0 *)vl;
      vorbis_info_residue0 *info=look->info;
    
      /* move all this setup out later */
      int samples_per_partition=info->grouping;
      int possible_partitions=info->partitions;
      int n=info->end-info->begin;
    
      int partvals=n/samples_per_partition;
      long **partword=_vorbis_block_alloc(vb,ch*sizeof(*partword));
      float scale=100./samples_per_partition;
    
      /* we find the partition type for each partition of each
         channel.  We'll go back and do the interleaved encoding in a
         bit.  For now, clarity */
    
      for(i=0;i<ch;i++){
        partword[i]=_vorbis_block_alloc(vb,n/samples_per_partition*sizeof(*partword[i]));
        memset(partword[i],0,n/samples_per_partition*sizeof(*partword[i]));
      }
    
      for(i=0;i<partvals;i++){
        int offset=i*samples_per_partition+info->begin;
        for(j=0;j<ch;j++){
          int max=0;
          int ent=0;
          for(k=0;k<samples_per_partition;k++){
            if(abs(in[j][offset+k])>max)max=abs(in[j][offset+k]);
            ent+=abs(in[j][offset+k]);
          }
          ent*=scale;
    
          for(k=0;k<possible_partitions-1;k++)
            if(max<=info->classmetric1[k] &&
               (info->classmetric2[k]<0 || ent<info->classmetric2[k]))
              break;
    
          partword[j][i]=k;
        }
      }
    
    #ifdef TRAIN_RESAUX
      {
        FILE *of;
        char buffer[80];
    
        for(i=0;i<ch;i++){
          sprintf(buffer,"resaux_%d.vqd",look->train_seq);
          of=fopen(buffer,"a");
          for(j=0;j<partvals;j++)
            fprintf(of,"%ld, ",partword[i][j]);
          fprintf(of,"\n");
          fclose(of);
        }
      }
    #endif
      look->frames++;
    
      return(partword);
    }
    
    /* designed for stereo or other modes where the partition size is an
       integer multiple of the number of channels encoded in the current
       submap */
    static long **_2class(vorbis_block *vb,vorbis_look_residue *vl,int **in,
                          int ch){
      long i,j,k,l;
      vorbis_look_residue0 *look=(vorbis_look_residue0 *)vl;
      vorbis_info_residue0 *info=look->info;
    
      /* move all this setup out later */
      int samples_per_partition=info->grouping;
      int possible_partitions=info->partitions;
      int n=info->end-info->begin;
    
      int partvals=n/samples_per_partition;
      long **partword=_vorbis_block_alloc(vb,sizeof(*partword));
    
    #if defined(TRAIN_RES) || defined (TRAIN_RESAUX)
      FILE *of;
      char buffer[80];
    #endif
    
      partword[0]=_vorbis_block_alloc(vb,partvals*sizeof(*partword[0]));
      memset(partword[0],0,partvals*sizeof(*partword[0]));
    
      for(i=0,l=info->begin/ch;i<partvals;i++){
        int magmax=0;
        int angmax=0;
        for(j=0;j<samples_per_partition;j+=ch){
          if(abs(in[0][l])>magmax)magmax=abs(in[0][l]);
          for(k=1;k<ch;k++)
            if(abs(in[k][l])>angmax)angmax=abs(in[k][l]);
          l++;
        }
    
        for(j=0;j<possible_partitions-1;j++)
          if(magmax<=info->classmetric1[j] &&
             angmax<=info->classmetric2[j])
            break;
    
        partword[0][i]=j;
    
      }
    
    #ifdef TRAIN_RESAUX
      sprintf(buffer,"resaux_%d.vqd",look->train_seq);
      of=fopen(buffer,"a");
      for(i=0;i<partvals;i++)
        fprintf(of,"%ld, ",partword[0][i]);
      fprintf(of,"\n");
      fclose(of);
    #endif
    
      look->frames++;
    
      return(partword);
    }
    
    static int _01forward(oggpack_buffer *opb,
                          vorbis_look_residue *vl,
                          int **in,int ch,
                          long **partword,
    #ifdef TRAIN_RES
                          int (*encode)(oggpack_buffer *,int *,int,
                                        codebook *,long *),
                          int submap
    #else
                          int (*encode)(oggpack_buffer *,int *,int,
                                        codebook *)
    #endif
    ){
      long i,j,k,s;
      vorbis_look_residue0 *look=(vorbis_look_residue0 *)vl;
      vorbis_info_residue0 *info=look->info;
    
    #ifdef TRAIN_RES
      look->submap=submap;
    #endif
    
      /* move all this setup out later */
      int samples_per_partition=info->grouping;
      int possible_partitions=info->partitions;
      int partitions_per_word=look->phrasebook->dim;
      int n=info->end-info->begin;
    
      int partvals=n/samples_per_partition;
      long resbits[128];
      long resvals[128];
    
    #ifdef TRAIN_RES
      for(i=0;i<ch;i++)
        for(j=info->begin;j<info->end;j++){
          if(in[i][j]>look->tmax)look->tmax=in[i][j];
          if(in[i][j]<look->tmin)look->tmin=in[i][j];
        }
    #endif
    
      memset(resbits,0,sizeof(resbits));
      memset(resvals,0,sizeof(resvals));
    
      /* we code the partition words for each channel, then the residual
         words for a partition per channel until we've written all the
         residual words for that partition word.  Then write the next
         partition channel words... */
    
      for(s=0;s<look->stages;s++){
    
        for(i=0;i<partvals;){
    
          /* first we encode a partition codeword for each channel */
          if(s==0){
            for(j=0;j<ch;j++){
              long val=partword[j][i];
              for(k=1;k<partitions_per_word;k++){
                val*=possible_partitions;
                if(i+k<partvals)
                  val+=partword[j][i+k];
              }
    
              /* training hack */
              if(val<look->phrasebook->entries)
                look->phrasebits+=vorbis_book_encode(look->phrasebook,val,opb);
    #if 0 /*def TRAIN_RES*/
              else
                fprintf(stderr,"!");
    #endif
    
            }
          }
    
          /* now we encode interleaved residual values for the partitions */
          for(k=0;k<partitions_per_word && i<partvals;k++,i++){
            long offset=i*samples_per_partition+info->begin;
    
            for(j=0;j<ch;j++){
              if(s==0)resvals[partword[j][i]]+=samples_per_partition;
              if(info->secondstages[partword[j][i]]&(1<<s)){
                codebook *statebook=look->partbooks[partword[j][i]][s];
                if(statebook){
                  int ret;
    #ifdef TRAIN_RES
                  long *accumulator=NULL;
                  accumulator=look->training_data[s][partword[j][i]];
                  {
                    int l;
                    int *samples=in[j]+offset;
                    for(l=0;l<samples_per_partition;l++){
                      if(samples[l]<look->training_min[s][partword[j][i]])
                        look->training_min[s][partword[j][i]]=samples[l];
                      if(samples[l]>look->training_max[s][partword[j][i]])
                        look->training_max[s][partword[j][i]]=samples[l];
                    }
                  }
                  ret=encode(opb,in[j]+offset,samples_per_partition,
                             statebook,accumulator);
    #else
                  ret=encode(opb,in[j]+offset,samples_per_partition,
                             statebook);
    #endif
    
                  look->postbits+=ret;
                  resbits[partword[j][i]]+=ret;
                }
              }
            }
          }
        }
      }
    
      return(0);
    }
    
    /* a truncated packet here just means 'stop working'; it's not an error */
    static int _01inverse(vorbis_block *vb,vorbis_look_residue *vl,
                          float **in,int ch,
                          long (*decodepart)(codebook *, float *,
                                             oggpack_buffer *,int)){
    
      long i,j,k,l,s;
      vorbis_look_residue0 *look=(vorbis_look_residue0 *)vl;
      vorbis_info_residue0 *info=look->info;
    
      /* move all this setup out later */
      int samples_per_partition=info->grouping;
      int partitions_per_word=look->phrasebook->dim;
      int max=vb->pcmend>>1;
      int end=(info->end<max?info->end:max);
      int n=end-info->begin;
    
      if(n>0){
        int partvals=n/samples_per_partition;
        int partwords=(partvals+partitions_per_word-1)/partitions_per_word;
        int ***partword=alloca(ch*sizeof(*partword));
    
        for(j=0;j<ch;j++)
          partword[j]=_vorbis_block_alloc(vb,partwords*sizeof(*partword[j]));
    
        for(s=0;s<look->stages;s++){
    
          /* each loop decodes on partition codeword containing
             partitions_per_word partitions */
          for(i=0,l=0;i<partvals;l++){
            if(s==0){
              /* fetch the partition word for each channel */
              for(j=0;j<ch;j++){
                int temp=vorbis_book_decode(look->phrasebook,&vb->opb);
    
                if(temp==-1 || temp>=info->partvals)goto eopbreak;
                partword[j][l]=look->decodemap[temp];
                if(partword[j][l]==NULL)goto errout;
              }
            }
    
            /* now we decode residual values for the partitions */
            for(k=0;k<partitions_per_word && i<partvals;k++,i++)
              for(j=0;j<ch;j++){
                long offset=info->begin+i*samples_per_partition;
                if(info->secondstages[partword[j][l][k]]&(1<<s)){
                  codebook *stagebook=look->partbooks[partword[j][l][k]][s];
                  if(stagebook){
                    if(decodepart(stagebook,in[j]+offset,&vb->opb,
                                  samples_per_partition)==-1)goto eopbreak;
                  }
                }
              }
          }
        }
      }
     errout:
     eopbreak:
      return(0);
    }
    
    int res0_inverse(vorbis_block *vb,vorbis_look_residue *vl,
                     float **in,int *nonzero,int ch){
      int i,used=0;
      for(i=0;i<ch;i++)
        if(nonzero[i])
          in[used++]=in[i];
      if(used)
        return(_01inverse(vb,vl,in,used,vorbis_book_decodevs_add));
      else
        return(0);
    }
    
    int res1_forward(oggpack_buffer *opb,vorbis_block *vb,vorbis_look_residue *vl,
                     int **in,int *nonzero,int ch, long **partword, int submap){
      int i,used=0;
      (void)vb;
      for(i=0;i<ch;i++)
        if(nonzero[i])
          in[used++]=in[i];
    
      if(used){
    #ifdef TRAIN_RES
        return _01forward(opb,vl,in,used,partword,_encodepart,submap);
    #else
        (void)submap;
        return _01forward(opb,vl,in,used,partword,_encodepart);
    #endif
      }else{
        return(0);
      }
    }
    
    long **res1_class(vorbis_block *vb,vorbis_look_residue *vl,
                      int **in,int *nonzero,int ch){
      int i,used=0;
      for(i=0;i<ch;i++)
        if(nonzero[i])
          in[used++]=in[i];
      if(used)
        return(_01class(vb,vl,in,used));
      else
        return(0);
    }
    
    int res1_inverse(vorbis_block *vb,vorbis_look_residue *vl,
                     float **in,int *nonzero,int ch){
      int i,used=0;
      for(i=0;i<ch;i++)
        if(nonzero[i])
          in[used++]=in[i];
      if(used)
        return(_01inverse(vb,vl,in,used,vorbis_book_decodev_add));
      else
        return(0);
    }
    
    long **res2_class(vorbis_block *vb,vorbis_look_residue *vl,
                      int **in,int *nonzero,int ch){
      int i,used=0;
      for(i=0;i<ch;i++)
        if(nonzero[i])used++;
      if(used)
        return(_2class(vb,vl,in,ch));
      else
        return(0);
    }
    
    /* res2 is slightly more different; all the channels are interleaved
       into a single vector and encoded. */
    
    int res2_forward(oggpack_buffer *opb,
                     vorbis_block *vb,vorbis_look_residue *vl,
                     int **in,int *nonzero,int ch, long **partword,int submap){
      long i,j,k,n=vb->pcmend/2,used=0;
    
      /* don't duplicate the code; use a working vector hack for now and
         reshape ourselves into a single channel res1 */
      /* ugly; reallocs for each coupling pass :-( */
      int *work=_vorbis_block_alloc(vb,ch*n*sizeof(*work));
      for(i=0;i<ch;i++){
        int *pcm=in[i];
        if(nonzero[i])used++;
        for(j=0,k=i;j<n;j++,k+=ch)
          work[k]=pcm[j];
      }
    
      if(used){
    #ifdef TRAIN_RES
        return _01forward(opb,vl,&work,1,partword,_encodepart,submap);
    #else
        (void)submap;
        return _01forward(opb,vl,&work,1,partword,_encodepart);
    #endif
      }else{
        return(0);
      }
    }
    
    /* duplicate code here as speed is somewhat more important */
    int res2_inverse(vorbis_block *vb,vorbis_look_residue *vl,
                     float **in,int *nonzero,int ch){
      long i,k,l,s;
      vorbis_look_residue0 *look=(vorbis_look_residue0 *)vl;
      vorbis_info_residue0 *info=look->info;
    
      /* move all this setup out later */
      int samples_per_partition=info->grouping;
      int partitions_per_word=look->phrasebook->dim;
      int max=(vb->pcmend*ch)>>1;
      int end=(info->end<max?info->end:max);
      int n=end-info->begin;
    
      if(n>0){
        int partvals=n/samples_per_partition;
        int partwords=(partvals+partitions_per_word-1)/partitions_per_word;
        int **partword=_vorbis_block_alloc(vb,partwords*sizeof(*partword));
    
        for(i=0;i<ch;i++)if(nonzero[i])break;
        if(i==ch)return(0); /* no nonzero vectors */
    
        for(s=0;s<look->stages;s++){
          for(i=0,l=0;i<partvals;l++){
    
            if(s==0){
              /* fetch the partition word */
              int temp=vorbis_book_decode(look->phrasebook,&vb->opb);
              if(temp==-1 || temp>=info->partvals)goto eopbreak;
              partword[l]=look->decodemap[temp];
              if(partword[l]==NULL)goto errout;
            }
    
            /* now we decode residual values for the partitions */
            for(k=0;k<partitions_per_word && i<partvals;k++,i++)
              if(info->secondstages[partword[l][k]]&(1<<s)){
                codebook *stagebook=look->partbooks[partword[l][k]][s];
    
                if(stagebook){
                  if(vorbis_book_decodevv_add(stagebook,in,
                                              i*samples_per_partition+info->begin,ch,
                                              &vb->opb,samples_per_partition)==-1)
                    goto eopbreak;
                }
              }
          }
        }
      }
     errout:
     eopbreak:
      return(0);
    }
    
    
    const vorbis_func_residue residue0_exportbundle={
      NULL,
      &res0_unpack,
      &res0_look,
      &res0_free_info,
      &res0_free_look,
      NULL,
      NULL,
      &res0_inverse
    };
    
    const vorbis_func_residue residue1_exportbundle={
      &res0_pack,
      &res0_unpack,
      &res0_look,
      &res0_free_info,
      &res0_free_look,
      &res1_class,
      &res1_forward,
      &res1_inverse
    };
    
    const vorbis_func_residue residue2_exportbundle={
      &res0_pack,
      &res0_unpack,
      &res0_look,
      &res0_free_info,
      &res0_free_look,
      &res2_class,
      &res2_forward,
      &res2_inverse
    };