#!/bin/bash
  
  # Copyright 2012  Johns Hopkins University (Author: Daniel Povey).  Apache 2.0.
  
  # This script does decoding with an SGMM system, with speaker vectors. 
  # If the SGMM system was
  # built on top of fMLLR transforms from a conventional system, you should
  # provide the --transform-dir option.
  
  # Begin configuration section.
  stage=1
  transform_dir=    # dir to find fMLLR transforms.
  nj=4 # number of decoding jobs.
  acwt=0.1  # Just a default value, used for adaptation and beam-pruning..
  cmd=run.pl
  beam=13.0
  gselect=15  # Number of Gaussian-selection indices for SGMMs.  [Note:
              # the first_pass_gselect variable is used for the 1st pass of
              # decoding and can be tighter.
  first_pass_gselect=3 # Use a smaller number of Gaussian-selection indices in 
              # the 1st pass of decoding (lattice generation).
  max_active=7000
  max_arcs=-1
  lat_beam=6.0 # Beam we use in lattice generation.
  vecs_beam=4.0 # Beam we use to prune lattices while getting posteriors for 
      # speaker-vector computation.  Can be quite tight (actually we could
      # probably just do best-path.
  use_fmllr=false
  fmllr_iters=10
  fmllr_min_count=1000
  num_threads=1 # if >1, will use gmm-latgen-faster-parallel
  parallel_opts=  # If you supply num-threads, you should supply this too.
  skip_scoring=false
  scoring_opts=
  # note: there are no more min-lmwt and max-lmwt options, instead use
  # e.g. --scoring-opts "--min-lmwt 1 --max-lmwt 20"
  # 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 3 ]; then
    echo "Usage: steps/decode_sgmm2.sh [options] <graph-dir> <data-dir> <decode-dir>"
    echo " e.g.: steps/decode_sgmm2.sh --transform-dir exp/tri3b/decode_dev93_tgpr \\"
    echo "      exp/sgmm3a/graph_tgpr data/test_dev93 exp/sgmm3a/decode_dev93_tgpr"
    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 "  --nj <nj>                                # number of parallel jobs"
    echo "  --cmd <cmd>                              # Command to run in parallel with"
    echo "  --beam <beam>                            # Decoding beam; default 13.0"
    exit 1;
  fi
  
  graphdir=$1
  data=$2
  dir=$3
  srcdir=`dirname $dir`; # Assume model directory one level up from decoding directory.
  
  for f in $graphdir/HCLG.fst $data/feats.scp $srcdir/final.mdl; do
    [ ! -f $f ] && echo "$0: no such file $f" && exit 1;
  done
  
  sdata=$data/split$nj;
  silphonelist=`cat $graphdir/phones/silence.csl` || exit 1
  gselect_opt="--gselect=ark,s,cs:gunzip -c $dir/gselect.JOB.gz|"
  gselect_opt_1stpass="$gselect_opt copy-gselect --n=$first_pass_gselect ark:- ark:- |"
  
  mkdir -p $dir/log
  [[ -d $sdata && $data/feats.scp -ot $sdata ]] || split_data.sh $data $nj || exit 1;
  echo $nj > $dir/num_jobs
  splice_opts=`cat $srcdir/splice_opts 2>/dev/null` # frame-splicing options.
  thread_string=
  [ $num_threads -gt 1 ] && thread_string="-parallel --num-threads=$num_threads"
  
  ## Set up features.
  if [ -f $srcdir/final.mat ]; then feat_type=lda; else feat_type=delta; fi
  echo "$0: feature type is $feat_type"
  
  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 "$0: invalid feature type $feat_type" && exit 1;
  esac
  if [ ! -z "$transform_dir" ]; then
    echo "$0: using transforms from $transform_dir"
    [ ! -f $transform_dir/trans.1 ] && echo "$0: no such file $transform_dir/trans.1" && exit 1;
    [ "$nj" -ne "`cat $transform_dir/num_jobs`" ] \
      && echo "$0: #jobs mismatch with transform-dir." && exit 1;
    feats="$feats transform-feats --utt2spk=ark:$sdata/JOB/utt2spk ark,s,cs:$transform_dir/trans.JOB ark:- ark:- |"
  elif 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
  ##
  
  ## Save Gaussian-selection info to disk.
  # Note: we can use final.mdl regardless of whether there is an alignment model--
  # they use the same UBM.
  
  if [ $stage -le 1 ]; then
    $cmd JOB=1:$nj $dir/log/gselect.JOB.log \
      sgmm2-gselect --full-gmm-nbest=$gselect $srcdir/final.mdl \
      "$feats" "ark:|gzip -c >$dir/gselect.JOB.gz" || exit 1;
  fi
  
  # Generate state-level lattice which we can rescore.  This is done with the alignment
  # model and no speaker-vectors.
  if [ $stage -le 2 ]; then
    $cmd $parallel_opts JOB=1:$nj $dir/log/decode_pass1.JOB.log \
      sgmm2-latgen-faster$thread_string --max-active=$max_active --beam=$beam --lattice-beam=$lat_beam \
      --max-arcs=$max_arcs --acoustic-scale=$acwt --determinize-lattice=false --allow-partial=true \
      --word-symbol-table=$graphdir/words.txt "$gselect_opt_1stpass" $srcdir/final.alimdl \
      $graphdir/HCLG.fst "$feats" "ark:|gzip -c > $dir/pre_lat.JOB.gz" || exit 1;
  fi
  
  # Estimate speaker vectors (1st pass).  Prune before determinizing
  # because determinization can take a while on un-pruned lattices.
  # Note: the sgmm2-post-to-gpost stage is necessary because we have
  # a separate alignment-model and final model, otherwise we'd skip it 
  # and use sgmm2-est-spkvecs.
  if [ $stage -le 3 ]; then
    $cmd JOB=1:$nj $dir/log/vecs_pass1.JOB.log \
      gunzip -c $dir/pre_lat.JOB.gz \| \
      lattice-prune --acoustic-scale=$acwt --beam=$vecs_beam ark:- ark:- \| \
      lattice-determinize-pruned --acoustic-scale=$acwt --beam=$vecs_beam ark:- ark:- \| \
      lattice-to-post --acoustic-scale=$acwt ark:- ark:- \| \
      weight-silence-post 0.0 $silphonelist $srcdir/final.alimdl ark:- ark:- \| \
      sgmm2-post-to-gpost "$gselect_opt" $srcdir/final.alimdl "$feats" ark:- ark:- \| \
      sgmm2-est-spkvecs-gpost --spk2utt=ark:$sdata/JOB/spk2utt \
       $srcdir/final.mdl "$feats" ark,s,cs:- "ark:$dir/pre_vecs.JOB" || exit 1;
  fi
  
  # Estimate speaker vectors (2nd pass).  Since we already have spk vectors,
  # at this point we need to rescore the lattice to get the correct posteriors.
  if [ $stage -le 4 ]; then
    $cmd JOB=1:$nj $dir/log/vecs_pass2.JOB.log \
      gunzip -c $dir/pre_lat.JOB.gz \| \
      sgmm2-rescore-lattice --spk-vecs=ark:$dir/pre_vecs.JOB --utt2spk=ark:$sdata/JOB/utt2spk \
        "$gselect_opt" $srcdir/final.mdl ark:- "$feats" ark:- \| \
      lattice-prune --acoustic-scale=$acwt --beam=$vecs_beam ark:- ark:- \| \
      lattice-determinize-pruned --acoustic-scale=$acwt --beam=$vecs_beam ark:- ark:- \| \
      lattice-to-post --acoustic-scale=$acwt ark:- ark:- \| \
      weight-silence-post 0.0 $silphonelist $srcdir/final.mdl ark:- ark:- \| \
      sgmm2-est-spkvecs --spk2utt=ark:$sdata/JOB/spk2utt "$gselect_opt" --spk-vecs=ark:$dir/pre_vecs.JOB \
       $srcdir/final.mdl "$feats" ark,s,cs:- "ark:$dir/vecs.JOB" || exit 1;
  fi
  rm $dir/pre_vecs.*
  
  if $use_fmllr; then
    # Estimate fMLLR transforms (note: these may be on top of any
    # fMLLR transforms estimated with the baseline GMM system.
    if [ $stage -le 5 ]; then # compute fMLLR transforms.
      echo "$0: computing fMLLR transforms."
      if [ ! -f $srcdir/final.fmllr_mdl ] || [ $srcdir/final.fmllr_mdl -ot $srcdir/final.mdl ]; then
        echo "$0: computing pre-transform for fMLLR computation."
        sgmm2-comp-prexform $srcdir/final.mdl $srcdir/final.occs $srcdir/final.fmllr_mdl || exit 1;
      fi
      $cmd JOB=1:$nj $dir/log/fmllr.JOB.log \
        gunzip -c $dir/pre_lat.JOB.gz \| \
        sgmm2-rescore-lattice --spk-vecs=ark:$dir/vecs.JOB --utt2spk=ark:$sdata/JOB/utt2spk \
        "$gselect_opt" $srcdir/final.mdl ark:- "$feats" ark:- \| \
        lattice-prune --acoustic-scale=$acwt --beam=$vecs_beam ark:- ark:- \| \
        lattice-determinize-pruned --acoustic-scale=$acwt --beam=$vecs_beam ark:- ark:- \| \
        lattice-to-post --acoustic-scale=$acwt ark:- ark:- \| \
        weight-silence-post 0.0 $silphonelist $srcdir/final.mdl ark:- ark:- \| \
        sgmm2-est-fmllr --spk2utt=ark:$sdata/JOB/spk2utt "$gselect_opt" --spk-vecs=ark:$dir/vecs.JOB \
         --fmllr-iters=$fmllr_iters --fmllr-min-count=$fmllr_min_count \
        $srcdir/final.fmllr_mdl "$feats" ark,s,cs:- "ark:$dir/trans.JOB" || exit 1;
    fi
    feats="$feats transform-feats --utt2spk=ark:$sdata/JOB/utt2spk ark,s,cs:$dir/trans.JOB ark:- ark:- |"  
  fi
  
  # Now rescore the state-level lattices with the adapted features and the
  # corresponding model.  Prune and determinize the lattices to limit
  # their size.
  if [ $stage -le 6 ]; then
    $cmd $parallel_opts JOB=1:$nj $dir/log/rescore.JOB.log \
      sgmm2-rescore-lattice "$gselect_opt" --utt2spk=ark:$sdata/JOB/utt2spk --spk-vecs=ark:$dir/vecs.JOB \
      $srcdir/final.mdl "ark:gunzip -c $dir/pre_lat.JOB.gz|" "$feats" ark:- \| \
      lattice-determinize-pruned$thread_string --acoustic-scale=$acwt --beam=$lat_beam ark:- \
      "ark:|gzip -c > $dir/lat.JOB.gz" || exit 1;
  fi
  rm $dir/pre_lat.*.gz
  
  # The output of this script is the files "lat.*.gz"-- we'll rescore this at different
  # acoustic scales to get the final output.
  
  
  if [ $stage -le 7 ]; then
    if ! $skip_scoring ; then
      [ ! -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" $data $graphdir $dir
    fi
  fi
  
  exit 0;