#!/bin/bash
  
  # Copyright 2012  Johns Hopkins University (Author: Daniel Povey).  Apache 2.0.
  
  # This script does decoding with an SGMM system, by rescoring lattices
  # generated from a previous SGMM system.  This version does the "predictive"
  # SGMM, where we subtract some constant times the log-prob of the left
  # few spliced frames, and the same for the right few.
  # The directory with the lattices
  # is assumed to contain any speaker vectors, if used.  This script just
  # adds into the acoustic scores, (some constant, default -0.25) times
  # the acoustic score of the left model, and the same for the right model.
  
  # the lattices one final time, using the same setup as the final decoding
  # pass of the source dir.  The assumption is that the model may have
  # been discriminatively trained.
  
  # If the system was built on top of fMLLR transforms from a conventional system,
  # you should provide the --transform-dir option.
  
  # Begin configuration section.
  stage=0
  transform_dir=    # dir to find fMLLR transforms.
  cmd=run.pl
  iter=final
  prob_scale=-0.25
  dimensions=0:13:104:117
  # End configuration section.
  
  echo "$0 $@"  # Print the command line for logging
  
  [ -f ./path.sh ] && . ./path.sh; # source the path.
  . parse_options.sh || exit 1;
  
  if [ $# -ne 5 ]; then
    echo "Usage: steps/decode_sgmm_rescore_project.sh [options] <full-lda-mat> <graph-dir|lang-dir> <data-dir> <old-decode-dir> <decode-dir>"
    echo " e.g.: steps/decode_sgmm_rescore_project.sh --transform-dir exp/tri3b/decode_dev93_tgpr \\"
    echo "     exp/tri2b/full.mat exp/sgmm3a/graph_tgpr data/test_dev93 exp/sgmm3a/decode_dev93_tgpr exp/sgmm3a/decode_dev93_tgpr_predict"
    echo "main options (for others, see top of script file)"
    echo "  --transform-dir <decoding-dir>           # directory of previous decoding"
    echo "                                           # where we can find transforms for SAT systems."
    echo "  --config <config-file>                   # config containing options"
    echo "  --cmd <cmd>                              # Command to run in parallel with"
    echo "  --prob-scale <scale>                     # Default -0.25, scale on left and right models."
    exit 1;
  fi
  
  full_lda_mat=$1
  graphdir=$2
  data=$3
  olddir=$4
  dir=$5
  srcdir=`dirname $dir`; # Assume model directory one level up from decoding directory.
  
  for f in $full_lda_mat $graphdir/words.txt $data/feats.scp $olddir/lat.1.gz \
     $olddir/gselect.1.gz $srcdir/$iter.mdl; do
    [ ! -f $f ] && echo "$0: no such file $f" && exit 1;
  done
  
  nj=`cat $olddir/num_jobs` || exit 1;
  sdata=$data/split$nj;
  splice_opts=`cat $srcdir/splice_opts 2>/dev/null`
  
  mkdir -p $dir/log
  [[ -d $sdata && $data/feats.scp -ot $sdata ]] || split_data.sh $data $nj || exit 1;
  echo $nj > $dir/num_jobs
  
  if [ -f $olddir/vecs.1 ]; then
    echo "$0: using speaker vectors from $olddir"
    spkvecs_opt="--spk-vecs=ark:$olddir/vecs.JOB --utt2spk=ark:$sdata/JOB/utt2spk"
  else
    echo "$0: no speaker vectors found."
    spkvecs_opt=
  fi
  
  if [ $stage -le 0 ]; then
    # Get full LDA+MLLT mat and its inverse.  Note: the full LDA+MLLT mat is
    # the LDA+MLLT mat, plus the "rejected" rows of the LDA matrix.
    $cmd $dir/log/get_full_lda.log \
      get-full-lda-mat $srcdir/final.mat $full_lda_mat $dir/full.mat $dir/full_inv.mat || exit 1;
  fi
  
  if [ $stage -le 1 ]; then
    left_start=`echo $dimensions | cut '-d:' -f 1`;
    left_end=`echo $dimensions | cut '-d:' -f 2`;
    right_start=`echo $dimensions | cut '-d:' -f 3`;
    right_end=`echo $dimensions | cut '-d:' -f 4`;
  
    # Prepare left and right models.  For now, the dimensions are hardwired (e.g., 13 MFCCs and splice 9 frames).
    # Note: the choice of dividing by the prob of the left 4 and the right 4 frames is a bit arbitrary and
    # we could investigate different configurations.
    $cmd $dir/log/left.log \
      sgmm2-project --start-dim=$left_start --end-dim=$left_end $srcdir/final.mdl $dir/full.mat $dir/left.mdl $dir/left.mat || exit 1;
    $cmd $dir/log/right.log \
      sgmm2-project --start-dim=$right_start --end-dim=$right_end $srcdir/final.mdl $dir/full.mat $dir/right.mdl $dir/right.mat || exit 1;
  fi
  
  
  # we apply the scaling on the new acoustic probs by adding the inverse
  # of that to the old acoustic probs, and then later inverting again.
  # this has to do with limitations in sgmm2-rescore-lattice: we can only
  # scale the *old* acoustic probs, not the new ones.
  inverse_prob_scale=`perl -e "print (1.0 / $prob_scale);"`
  cur_lats="ark:gunzip -c $olddir/lat.JOB.gz | lattice-scale --acoustic-scale=$inverse_prob_scale ark:- ark:- |"
  
  ## Set up features.  Note: we only support LDA+MLLT features, this
  ## is inherent in the method, we could not support deltas.
  
  for model_type in left right; do
  
    feats="ark,s,cs:apply-cmvn --norm-vars=false --utt2spk=ark:$sdata/JOB/utt2spk scp:$sdata/JOB/cmvn.scp scp:$sdata/JOB/feats.scp ark:- | splice-feats $splice_opts ark:- ark:- |" # spliced features.
    if [ ! -z "$transform_dir" ]; then  # using speaker-specific transforms.
       # we want to transform in the sequence: $dir/full.mat, then the result of
       # (extend-transform-dim $transform_dir/trans.JOB), then $dir/full_inv.mat to
       # get back to the spliced space, then the left.mat or right.mat.  But
       # note that compose-transforms operates in matrix-multiplication order,
       # which is opposite from the "order of applying the transforms" order.
       new_dim=$[`copy-matrix --binary=false $dir/full.mat - | wc -l` - 1]; # 117 in normal case.
       feats="$feats transform-feats --utt2spk=ark:$sdata/JOB/utt2spk 'ark:extend-transform-dim --new-dimension=$new_dim ark:$transform_dir/trans.JOB ark:- | compose-transforms ark:- $dir/full.mat ark:- | compose-transforms $dir/full_inv.mat ark:- ark:- | compose-transforms $dir/${model_type}.mat ark:- ark:- |' ark:- ark:- |"
    else  # else, we transform with the "left" or "right" matrix; these transform from the
          # spliced space.
       feats="$feats transform-feats $dir/${model_type}.mat |"
       # If we don't have the --transform-dir option, make sure the model was
       # trained in the same way.
       if grep 'transform-feats --utt2spk' $srcdir/log/acc.0.1.log 2>/dev/null; then
         echo "$0: **WARNING**: you seem to be using an SGMM system trained with transforms,"
         echo "  but you are not providing the --transform-dir option in test time."
       fi
    fi
    if [ -f $olddir/trans.1 ]; then
       echo "$0: warning: not using transforms in $olddir (this is just a "
       echo " limitation of the script right now, and could be fixed)."
    fi
    
    if [ $stage -le 2 ]; then
      echo "Getting gselect info for $model_type model."
      $cmd JOB=1:$nj $dir/log/gselect.$model_type.JOB.log \
         sgmm2-gselect $dir/$model_type.mdl "$feats" \
         "ark,t:|gzip -c >$dir/gselect.$model_type.JOB.gz" || exit 1;
    fi
    gselect_opt="--gselect=ark,s,cs:gunzip -c $dir/gselect.$model_type.JOB.gz|"
  
  
    # Rescore the state-level lattices with the model provided.  Just
    # one command in this script.
    # The --old-acoustic-scale=1.0 option means we just add the scores
    # to the old scores.
    if [ $stage -le 3 ]; then
      echo "$0: rescoring lattices with $model_type model"
      $cmd JOB=1:$nj $dir/log/rescore.${model_type}.JOB.log \
        sgmm2-rescore-lattice --old-acoustic-scale=1.0 "$gselect_opt" $spkvecs_opt \
        $dir/$model_type.mdl "$cur_lats" "$feats" \
        "ark:|gzip -c > $dir/lat.${model_type}.JOB.gz" || exit 1;
    fi
    cur_lats="ark:gunzip -c $dir/lat.${model_type}.JOB.gz |"
  done
  
  if [ $stage -le 4 ]; then
    echo "$0: getting final lattices."
    $cmd JOB=1:$nj $dir/log/scale_lats.JOB.log \
      lattice-scale --acoustic-scale=$prob_scale "$cur_lats" "ark:|gzip -c >$dir/lat.JOB.gz" \
     || exit 1;
  fi
  
  rm $dir/lat.{left,right}.*.gz 2>/dev/null  # note: if these still exist, it will
   # confuse the scoring script.
  
  [ ! -x local/score.sh ] && \
    echo "Not scoring because local/score.sh does not exist or not executable." && exit 1;
  local/score.sh --cmd "$cmd" $data $graphdir $dir
  
  exit 0;