#!/bin/bash
  
  # Copyright 2012  Johns Hopkins University (Author: Daniel Povey), BUT (Author: Mirko Hannemann)
  # Apache 2.0
  
  # Begin configuration section.  
  transform_dir=
  first_pass=
  iter=
  model= # You can specify the model to use (e.g. if you want to use the .alimdl)
  nj=4
  reverse=false
  cmd=run.pl
  max_active=7000
  beam=13.0
  latbeam=6.0
  acwt=0.083333 # note: only really affects pruning (scoring is on lattices).
  extra_beam=0.0 # small additional beam over varying beam
  max_beam=100.0 # maximum of varying beam
  scoring_opts=
  # 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 [ $# != 3 ]; then
     echo "Usage: steps/decode_fwdbwd.sh [options] <graph-dir> <data-dir> <decode-dir>"
     echo "... where <decode-dir> is assumed to be a sub-directory of the directory"
     echo " where the model is."
     echo "e.g.: steps/decode.sh exp/mono/graph_tgpr data/test_dev93 exp/mono/decode_dev93_tgpr"
     echo ""
     echo "This script works on CMN + (delta+delta-delta | LDA+MLLT) features; it works out"
     echo "what type of features you used (assuming it's one of these two)"
     echo ""
     echo "main options (for others, see top of script file)"
     echo "  --config <config-file>                           # config containing options"
     echo "  --first_pass <decode-dir>                        # decoding dir of first pass"
     echo "  --nj <nj>                                        # number of parallel jobs"
     echo "  --iter <iter>                                    # Iteration of model to test."
     echo "  --model <model>                                  # which model to use (e.g. to"
     echo "                                                   # specify the final.alimdl)"
     echo "  --cmd (utils/run.pl|utils/queue.pl <queue opts>) # how to run jobs."
     echo "  --transform_dir <trans-dir>                      # dir to find fMLLR transforms "
     echo "                                                   # speaker-adapted decoding"
     echo "  --scoring-opts <string>                          # options to local/score.sh"
     echo "  --reverse [true/false]                           # time reversal of features"
     exit 1;
  fi
  
  
  graphdir=$1
  data=$2
  dir=$3
  srcdir=`dirname $dir`; # The model directory is one level up from decoding directory.
  sdata=$data/split$nj;
  
  mkdir -p $dir/log
  [[ -d $sdata && $data/feats.scp -ot $sdata ]] || split_data.sh $data $nj || exit 1;
  echo $nj > $dir/num_jobs
  
  if [ -z "$model" ]; then # if --model <mdl> was not specified on the command line...
    if [ -z $iter ]; then model=$srcdir/final.mdl; 
    else model=$srcdir/$iter.mdl; fi
  fi
  
  for f in $sdata/1/feats.scp $sdata/1/cmvn.scp $model $graphdir/HCLG.fst $graphdir/words.txt; do
    [ ! -f $f ] && echo "decode_fwdbwd.sh: no such file $f" && exit 1;
  done
  
  if [ -f $srcdir/final.mat ]; then feat_type=lda; else feat_type=delta; fi
  echo "decode_fwdbwd.sh: feature type is $feat_type";
  
  splice_opts=`cat $srcdir/splice_opts 2>/dev/null`
  
  case $feat_type in
    delta) feats="ark,s,cs:apply-cmvn --norm-vars=false --utt2spk=ark:$sdata/JOB/utt2spk scp:$sdata/JOB/cmvn.scp scp:$sdata/JOB/feats.scp ark:- | add-deltas ark:- ark:- |";;
    lda) 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:- | transform-feats $srcdir/final.mat ark:- ark:- |";;
    *) echo "Invalid feature type $feat_type" && exit 1;
  esac
  if [ ! -z "$transform_dir" ]; then # add transforms to features...
    echo "Using fMLLR transforms from $transform_dir"
    [ ! -f $transform_dir/trans.1 ] && echo "Expected $transform_dir/trans.1 to exist."
    [ "`cat $transform_dir/num_jobs`" -ne $nj ] && \
       echo "Mismatch in number of jobs with $transform_dir";
    feats="$feats transform-feats --utt2spk=ark:$sdata/JOB/utt2spk ark:$transform_dir/trans.JOB ark:- ark:- |"
  fi
  if $reverse; then
    feats="$feats reverse-feats ark:- ark:- |"
  fi
  
  if [ -f $first_pass/lat.1.gz ]; then
    echo "converting first pass lattice to graph arc acceptor"
    $cmd JOB=1:$nj $dir/log/arc_graph.JOB.log \
      time lattice-arcgraph $model $graphdir/HCLG.fst \
      "ark:gunzip -c $first_pass/lat.JOB.gz|" ark,t:$dir/lat.JOB.arcs || exit 1;
      #  --write-lattices=ark,t:$dir/lat.det
      #  --acoustic-scale=$acwt --lattice-beam=$latbeam --prune=false \
  
    echo "decode with tracking first pass lattice"
    $cmd JOB=1:$nj $dir/log/decode_fwdbwd.JOB.log \
      gmm-latgen-tracking --max-active=$max_active --beam=$beam --lattice-beam=$latbeam \
        --acoustic-scale=$acwt --allow-partial=true \
        --extra-beam=$extra_beam --max-beam=$max_beam \
        --word-symbol-table=$graphdir/words.txt  --verbose=2 \
        $model $graphdir/HCLG.fst "$feats" ark:$dir/lat.JOB.arcs "ark:|gzip -c > $dir/lat.JOB.gz" || exit 1;
  
  else
    $cmd JOB=1:$nj $dir/log/decode.JOB.log \
     gmm-latgen-faster --max-active=$max_active --beam=$beam --lattice-beam=$latbeam \
       --acoustic-scale=$acwt --allow-partial=true \
       --word-symbol-table=$graphdir/words.txt \
       $model $graphdir/HCLG.fst "$feats" "ark:|gzip -c > $dir/lat.JOB.gz" || exit 1;
  fi
  
  [ ! -x local/score.sh ] && \
    echo "Not scoring because local/score.sh does not exist or not executable." && exit 1;
  local/score.sh $scoring_opts --cmd "$cmd" --reverse $reverse $scoring_opts $data $graphdir $dir
  
  echo "Decoding done."
  exit 0;