#!/bin/bash
  # Copyright 2012  Johns Hopkins University (Author: Daniel Povey)
  #           2019  Xiaohui Zhang
  # Apache 2.0
  
  
  # To be run from ..
  # Flat start and monophone training, with delta-delta features.
  # This script applies cepstral mean normalization (per speaker).
  
  # Begin configuration section.
  nj=4
  cmd=run.pl
  scale_opts="--transition-scale=1.0 --acoustic-scale=0.1 --self-loop-scale=0.1"
  num_iters=40    # Number of iterations of training
  max_iter_inc=30 # Last iter to increase #Gauss on.
  initial_beam=6 # beam used in the first iteration (set smaller to speed up initialization)
  regular_beam=10 # beam used after the first iteration
  retry_beam=40
  totgauss=1000 # Target #Gaussians.
  careful=false
  boost_silence=1.0 # Factor by which to boost silence likelihoods in alignment
  realign_iters="1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 23 26 29 32 35 38";
  config= # name of config file.
  stage=-4
  power=0.25 # exponent to determine number of gaussians from occurrence counts
  norm_vars=false # deprecated, prefer --cmvn-opts "--norm-vars=false"
  cmvn_opts=  # can be used to add extra options to cmvn.
  delta_opts= # can be used to add extra options to add-deltas
  # End configuration section.
  
  echo "$0 $@"  # Print the command line for logging
  
  if [ -f path.sh ]; then . ./path.sh; fi
  . parse_options.sh || exit 1;
  
  if [ $# != 3 ]; then
    echo "Usage: steps/train_mono.sh [options] <data-dir> <lang-dir> <exp-dir>"
    echo " e.g.: steps/train_mono.sh data/train.1k data/lang exp/mono"
    echo "main options (for others, see top of script file)"
    echo "  --config <config-file>                           # config containing options"
    echo "  --nj <nj>                                        # number of parallel jobs"
    echo "  --cmd (utils/run.pl|utils/queue.pl <queue opts>) # how to run jobs."
    exit 1;
  fi
  
  data=$1
  lang=$2
  dir=$3
  
  oov_sym=`cat $lang/oov.int` || exit 1;
  
  mkdir -p $dir/log
  echo $nj > $dir/num_jobs
  sdata=$data/split$nj;
  [[ -d $sdata && $data/feats.scp -ot $sdata ]] || split_data.sh $data $nj || exit 1;
  
  cp $lang/phones.txt $dir || exit 1;
  
  $norm_vars && cmvn_opts="--norm-vars=true $cmvn_opts"
  echo $cmvn_opts  > $dir/cmvn_opts # keep track of options to CMVN.
  [ ! -z $delta_opts ] && echo $delta_opts > $dir/delta_opts # keep track of options to delta
  
  feats="ark,s,cs:apply-cmvn $cmvn_opts --utt2spk=ark:$sdata/JOB/utt2spk scp:$sdata/JOB/cmvn.scp scp:$sdata/JOB/feats.scp ark:- | add-deltas $delta_opts ark:- ark:- |"
  example_feats="`echo $feats | sed s/JOB/1/g`";
  
  echo "$0: Initializing monophone system."
  
  [ ! -f $lang/phones/sets.int ] && exit 1;
  shared_phones_opt="--shared-phones=$lang/phones/sets.int"
  
  if [ $stage -le -3 ]; then
    # Note: JOB=1 just uses the 1st part of the features-- we only need a subset anyway.
    if ! feat_dim=`feat-to-dim "$example_feats" - 2>/dev/null` || [ -z $feat_dim ]; then
      feat-to-dim "$example_feats" -
      echo "error getting feature dimension"
      exit 1;
    fi
    $cmd JOB=1 $dir/log/init.log \
      gmm-init-mono $shared_phones_opt "--train-feats=$feats subset-feats --n=10 ark:- ark:-|" $lang/topo $feat_dim \
      $dir/0.mdl $dir/tree || exit 1;
  fi
  
  numgauss=`gmm-info --print-args=false $dir/0.mdl | grep gaussians | awk '{print $NF}'`
  incgauss=$[($totgauss-$numgauss)/$max_iter_inc] # per-iter increment for #Gauss
  
  if [ $stage -le -2 ]; then
    echo "$0: Compiling training graphs"
    $cmd JOB=1:$nj $dir/log/compile_graphs.JOB.log \
      compile-train-graphs --read-disambig-syms=$lang/phones/disambig.int $dir/tree $dir/0.mdl  $lang/L.fst \
      "ark:sym2int.pl --map-oov $oov_sym -f 2- $lang/words.txt < $sdata/JOB/text|" \
      "ark:|gzip -c >$dir/fsts.JOB.gz" || exit 1;
  fi
  
  if [ $stage -le -1 ]; then
    echo "$0: Aligning data equally (pass 0)"
    $cmd JOB=1:$nj $dir/log/align.0.JOB.log \
      align-equal-compiled "ark:gunzip -c $dir/fsts.JOB.gz|" "$feats" ark,t:-  \| \
      gmm-acc-stats-ali --binary=true $dir/0.mdl "$feats" ark:- \
      $dir/0.JOB.acc || exit 1;
  fi
  
  # In the following steps, the --min-gaussian-occupancy=3 option is important, otherwise
  # we fail to est "rare" phones and later on, they never align properly.
  
  if [ $stage -le 0 ]; then
    gmm-est --min-gaussian-occupancy=3  --mix-up=$numgauss --power=$power \
      $dir/0.mdl "gmm-sum-accs - $dir/0.*.acc|" $dir/1.mdl 2> $dir/log/update.0.log || exit 1;
    rm $dir/0.*.acc
  fi
  
  beam=$initial_beam # will change to regular_beam below after 1st pass
  # note: using slightly wider beams for WSJ vs. RM.
  x=1
  while [ $x -lt $num_iters ]; do
    echo "$0: Pass $x"
    if [ $stage -le $x ]; then
      if echo $realign_iters | grep -w $x >/dev/null; then
        echo "$0: Aligning data"
        mdl="gmm-boost-silence --boost=$boost_silence `cat $lang/phones/optional_silence.csl` $dir/$x.mdl - |"
        $cmd JOB=1:$nj $dir/log/align.$x.JOB.log \
          gmm-align-compiled $scale_opts --beam=$beam --retry-beam=$retry_beam --careful=$careful "$mdl" \
          "ark:gunzip -c $dir/fsts.JOB.gz|" "$feats" "ark,t:|gzip -c >$dir/ali.JOB.gz" \
          || exit 1;
      fi
      $cmd JOB=1:$nj $dir/log/acc.$x.JOB.log \
        gmm-acc-stats-ali  $dir/$x.mdl "$feats" "ark:gunzip -c $dir/ali.JOB.gz|" \
        $dir/$x.JOB.acc || exit 1;
  
      $cmd $dir/log/update.$x.log \
        gmm-est --write-occs=$dir/$[$x+1].occs --mix-up=$numgauss --power=$power $dir/$x.mdl \
        "gmm-sum-accs - $dir/$x.*.acc|" $dir/$[$x+1].mdl || exit 1;
      rm $dir/$x.mdl $dir/$x.*.acc $dir/$x.occs 2>/dev/null
    fi
    if [ $x -le $max_iter_inc ]; then
       numgauss=$[$numgauss+$incgauss];
    fi
    beam=$regular_beam
    x=$[$x+1]
  done
  
  ( cd $dir; rm final.{mdl,occs} 2>/dev/null; ln -s $x.mdl final.mdl; ln -s $x.occs final.occs )
  
  
  steps/diagnostic/analyze_alignments.sh --cmd "$cmd" $lang $dir
  utils/summarize_warnings.pl $dir/log
  
  steps/info/gmm_dir_info.pl $dir
  
  echo "$0: Done training monophone system in $dir"
  
  exit 0
  
  # example of showing the alignments:
  # show-alignments data/lang/phones.txt $dir/30.mdl "ark:gunzip -c $dir/ali.0.gz|" | head -4