#!/bin/bash
  
  # Copyright 2012 Johns Hopkins University (Author: Daniel Povey).  Apache 2.0.
  # This script, which will generally be called from other neural-net training
  # scripts, extracts the training examples used to train the neural net (and also
  # the validation examples used for diagnostics), and puts them in separate archives.
  
  # Begin configuration section.
  cmd=run.pl
  feat_type=
  num_utts_subset=300    # number of utterances in validation and training
                         # subsets used for shrinkage and diagnostics
  num_valid_frames_combine=0 # #valid frames for combination weights at the very end.
  num_train_frames_combine=10000 # # train frames for the above.
  num_frames_diagnostic=4000 # number of frames for "compute_prob" jobs
  samples_per_iter=200000 # each iteration of training, see this many samples
                          # per job.  This is just a guideline; it will pick a number
                          # that divides the number of samples in the entire data.
  transform_dir=     # If supplied, overrides alidir
  num_jobs_nnet=16    # Number of neural net jobs to run in parallel
  stage=0
  io_opts="--max-jobs-run 5" # for jobs with a lot of I/O, limits the number running at one time.
  splice_width=4 # meaning +- 4 frames on each side for second LDA
  left_context=
  right_context=
  random_copy=false
  online_ivector_dir=
  ivector_randomize_prob=0.0 # if >0.0, randomizes iVectors during training with
                             # this prob per iVector.
  cmvn_opts=  # can be used for specifying CMVN options, if feature type is not lda.
  
  echo "$0 $@"  # Print the command line for logging
  
  if [ -f path.sh ]; then . ./path.sh; fi
  . parse_options.sh || exit 1;
  
  
  if [ $# != 4 ]; then
    echo "Usage: steps/nnet2/get_egs.sh [opts] <data> <lang> <ali-dir> <exp-dir>"
    echo " e.g.: steps/nnet2/get_egs.sh data/train data/lang exp/tri3_ali exp/tri4_nnet"
    echo ""
    echo "Main options (for others, see top of script file)"
    echo "  --config <config-file>                           # config file containing options"
    echo "  --cmd (utils/run.pl;utils/queue.pl <queue opts>) # how to run jobs."
    echo "  --num-jobs-nnet <num-jobs;16>                    # Number of parallel jobs to use for main neural net"
    echo "                                                   # training (will affect results as well as speed; try 8, 16)"
    echo "                                                   # Note: if you increase this, you may want to also increase"
    echo "                                                   # the learning rate."
    echo "  --samples-per-iter <#samples;400000>             # Number of samples of data to process per iteration, per"
    echo "                                                   # process."
    echo "  --feat-type <lda|raw>                            # (by default it tries to guess).  The feature type you want"
    echo "                                                   # to use as input to the neural net."
    echo "  --splice-width <width;4>                         # Number of frames on each side to append for feature input"
    echo "  --left-context <width;4>                         # Number of frames on left side to append for feature input, overrides splice-width"
    echo "  --right-context <width;4>                        # Number of frames on right side to append for feature input, overrides splice-width"
    echo "  --num-frames-diagnostic <#frames;4000>           # Number of frames used in computing (train,valid) diagnostics"
    echo "  --num-valid-frames-combine <#frames;10000>       # Number of frames used in getting combination weights at the"
    echo "                                                   # very end."
    echo "  --stage <stage|0>                                # Used to run a partially-completed training process from somewhere in"
    echo "                                                   # the middle."
  
    exit 1;
  fi
  
  data=$1
  lang=$2  # kept for historical reasons, but never used.
  alidir=$3
  dir=$4
  
  [ -z "$left_context" ] && left_context=$splice_width
  [ -z "$right_context" ] && right_context=$splice_width
  
  
  # Check some files.
  [ ! -z "$online_ivector_dir" ] && \
    extra_files="$online_ivector_dir/ivector_online.scp $online_ivector_dir/ivector_period"
  
  for f in $data/feats.scp $lang/L.fst $alidir/ali.1.gz $alidir/final.mdl $alidir/tree $extra_files; do
    [ ! -f $f ] && echo "$0: no such file $f" && exit 1;
  done
  
  
  nj=`cat $alidir/num_jobs` || exit 1;  # number of jobs in alignment dir...
  
  sdata=$data/split$nj
  utils/split_data.sh $data $nj
  
  mkdir -p $dir/log
  cp $alidir/tree $dir
  
  utils/lang/check_phones_compatible.sh $lang/phones.txt $alidir/phones.txt || exit 1;
  cp $lang/phones.txt $dir || exit 1;
  
  # Get list of validation utterances.
  awk '{print $1}' $data/utt2spk | utils/shuffle_list.pl | head -$num_utts_subset \
      > $dir/valid_uttlist || exit 1;
  
  if [ -f $data/utt2uniq ]; then
    echo "File $data/utt2uniq exists, so augmenting valid_uttlist to"
    echo "include all perturbed versions of the same 'real' utterances."
    mv $dir/valid_uttlist $dir/valid_uttlist.tmp
    utils/utt2spk_to_spk2utt.pl $data/utt2uniq > $dir/uniq2utt
    cat $dir/valid_uttlist.tmp | utils/apply_map.pl $data/utt2uniq | \
      sort | uniq | utils/apply_map.pl $dir/uniq2utt | \
      awk '{for(n=1;n<=NF;n++) print $n;}' | sort  > $dir/valid_uttlist
    rm $dir/uniq2utt $dir/valid_uttlist.tmp
  fi
  
  awk '{print $1}' $data/utt2spk | utils/filter_scp.pl --exclude $dir/valid_uttlist | \
     utils/shuffle_list.pl | head -$num_utts_subset > $dir/train_subset_uttlist || exit 1;
  
  [ -z "$transform_dir" ] && transform_dir=$alidir
  
  ## Set up features.
  if [ -z $feat_type ]; then
    if [ -f $alidir/final.mat ] && [ ! -f $transform_dir/raw_trans.1 ]; then feat_type=lda; else feat_type=raw; fi
  fi
  echo "$0: feature type is $feat_type"
  
  case $feat_type in
    raw) feats="ark,s,cs:utils/filter_scp.pl --exclude $dir/valid_uttlist $sdata/JOB/feats.scp | apply-cmvn $cmvn_opts --utt2spk=ark:$sdata/JOB/utt2spk scp:$sdata/JOB/cmvn.scp scp:- ark:- |"
      valid_feats="ark,s,cs:utils/filter_scp.pl $dir/valid_uttlist $data/feats.scp | apply-cmvn $cmvn_opts --utt2spk=ark:$data/utt2spk scp:$data/cmvn.scp scp:- ark:- |"
      train_subset_feats="ark,s,cs:utils/filter_scp.pl $dir/train_subset_uttlist $data/feats.scp | apply-cmvn $cmvn_opts --utt2spk=ark:$data/utt2spk scp:$data/cmvn.scp scp:- ark:- |"
      echo $cmvn_opts >$dir/cmvn_opts
     ;;
    lda)
      splice_opts=`cat $alidir/splice_opts 2>/dev/null`
      cp $alidir/{splice_opts,cmvn_opts,final.mat} $dir || exit 1;
      [ ! -z "$cmvn_opts" ] && \
         echo "You cannot supply --cmvn-opts option if feature type is LDA." && exit 1;
      cmvn_opts=$(cat $dir/cmvn_opts)
      feats="ark,s,cs:utils/filter_scp.pl --exclude $dir/valid_uttlist $sdata/JOB/feats.scp | apply-cmvn $cmvn_opts --utt2spk=ark:$sdata/JOB/utt2spk scp:$sdata/JOB/cmvn.scp scp:- ark:- | splice-feats $splice_opts ark:- ark:- | transform-feats $dir/final.mat ark:- ark:- |"
      valid_feats="ark,s,cs:utils/filter_scp.pl $dir/valid_uttlist $data/feats.scp | apply-cmvn $cmvn_opts --utt2spk=ark:$data/utt2spk scp:$data/cmvn.scp scp:- ark:- | splice-feats $splice_opts ark:- ark:- | transform-feats $dir/final.mat ark:- ark:- |"
      train_subset_feats="ark,s,cs:utils/filter_scp.pl $dir/train_subset_uttlist $data/feats.scp | apply-cmvn $cmvn_opts --utt2spk=ark:$data/utt2spk scp:$data/cmvn.scp scp:- ark:- | splice-feats $splice_opts ark:- ark:- | transform-feats $dir/final.mat ark:- ark:- |"
      ;;
    *) echo "$0: invalid feature type $feat_type" && exit 1;
  esac
  
  if [ -f $transform_dir/trans.1 ] && [ $feat_type != "raw" ]; then
    echo "$0: using transforms from $transform_dir"
    feats="$feats transform-feats --utt2spk=ark:$sdata/JOB/utt2spk ark:$transform_dir/trans.JOB ark:- ark:- |"
    valid_feats="$valid_feats transform-feats --utt2spk=ark:$data/utt2spk 'ark:cat $transform_dir/trans.*|' ark:- ark:- |"
    train_subset_feats="$train_subset_feats transform-feats --utt2spk=ark:$data/utt2spk 'ark:cat $transform_dir/trans.*|' ark:- ark:- |"
  fi
  if [ -f $transform_dir/raw_trans.1 ] && [ $feat_type == "raw" ]; then
    echo "$0: using raw-fMLLR transforms from $transform_dir"
    feats="$feats transform-feats --utt2spk=ark:$sdata/JOB/utt2spk ark:$transform_dir/raw_trans.JOB ark:- ark:- |"
    valid_feats="$valid_feats transform-feats --utt2spk=ark:$data/utt2spk 'ark:cat $transform_dir/raw_trans.*|' ark:- ark:- |"
    train_subset_feats="$train_subset_feats transform-feats --utt2spk=ark:$data/utt2spk 'ark:cat $transform_dir/raw_trans.*|' ark:- ark:- |"
  fi
  if [ ! -z "$online_ivector_dir" ]; then
    feats_one="$(echo "$feats" | sed s:JOB:1:g)"
    ivector_dim=$(feat-to-dim scp:$online_ivector_dir/ivector_online.scp -) || exit 1;
    ivectors_opt="--const-feat-dim=$ivector_dim"
    ivector_period=$(cat $online_ivector_dir/ivector_period) || exit 1;
    feats="$feats paste-feats --length-tolerance=$ivector_period ark:- 'ark,s,cs:utils/filter_scp.pl $sdata/JOB/utt2spk $online_ivector_dir/ivector_online.scp | subsample-feats --n=-$ivector_period scp:- ark:- | ivector-randomize --randomize-prob=$ivector_randomize_prob ark:- ark:- |' ark:- |"
    valid_feats="$valid_feats paste-feats --length-tolerance=$ivector_period ark:- 'ark,s,cs:utils/filter_scp.pl $dir/valid_uttlist $online_ivector_dir/ivector_online.scp | subsample-feats --n=-$ivector_period scp:- ark:- | ivector-randomize --randomize-prob=$ivector_randomize_prob ark:- ark:- |' ark:- |"
    train_subset_feats="$train_subset_feats paste-feats --length-tolerance=$ivector_period ark:- 'ark,s,cs:utils/filter_scp.pl $dir/train_subset_uttlist $online_ivector_dir/ivector_online.scp | subsample-feats --n=-$ivector_period scp:- ark:- | ivector-randomize --randomize-prob=$ivector_randomize_prob ark:- ark:- |' ark:- |"
  fi
  
  if [ $stage -le 0 ]; then
    echo "$0: working out number of frames of training data"
    num_frames=$(steps/nnet2/get_num_frames.sh $data)
    echo $num_frames > $dir/num_frames
  else
    num_frames=`cat $dir/num_frames` || exit 1;
  fi
  
  # Working out number of iterations per epoch.
  iters_per_epoch=`perl -e "print int($num_frames/($samples_per_iter * $num_jobs_nnet) + 0.5);"` || exit 1;
  [ $iters_per_epoch -eq 0 ] && iters_per_epoch=1
  samples_per_iter_real=$[$num_frames/($num_jobs_nnet*$iters_per_epoch)]
  echo "$0: Every epoch, splitting the data up into $iters_per_epoch iterations,"
  echo "$0: giving samples-per-iteration of $samples_per_iter_real (you requested $samples_per_iter)."
  
  # Making soft links to storage directories.  This is a no-up unless
  # the subdirectory $dir/egs/storage/ exists.  See utils/create_split_dir.pl
  for x in `seq 1 $num_jobs_nnet`; do
    for y in `seq 0 $[$iters_per_epoch-1]`; do
      utils/create_data_link.pl $dir/egs/egs.$x.$y.ark
      utils/create_data_link.pl $dir/egs/egs_tmp.$x.$y.ark
    done
    for y in `seq 1 $nj`; do
      utils/create_data_link.pl $dir/egs/egs_orig.$x.$y.ark
    done
  done
  
  remove () { for x in $*; do [ -L $x ] && rm $(utils/make_absolute.sh $x); rm $x; done }
  
  nnet_context_opts="--left-context=$left_context --right-context=$right_context"
  mkdir -p $dir/egs
  
  if [ $stage -le 2 ]; then
    echo "Getting validation and training subset examples."
    rm $dir/.error 2>/dev/null
    echo "$0: extracting validation and training-subset alignments."
    set -o pipefail;
    for id in $(seq $nj); do gunzip -c $alidir/ali.$id.gz; done | \
      copy-int-vector ark:- ark,t:- | \
      utils/filter_scp.pl <(cat $dir/valid_uttlist $dir/train_subset_uttlist) | \
      gzip -c >$dir/ali_special.gz || exit 1;
    set +o pipefail; # unset the pipefail option.
  
    $cmd $dir/log/create_valid_subset.log \
      nnet-get-egs $ivectors_opt $nnet_context_opts "$valid_feats" \
      "ark,s,cs:gunzip -c $dir/ali_special.gz | ali-to-pdf $alidir/final.mdl ark:- ark:- | ali-to-post ark:- ark:- |" \
       "ark:$dir/egs/valid_all.egs" || touch $dir/.error &
    $cmd $dir/log/create_train_subset.log \
      nnet-get-egs $ivectors_opt $nnet_context_opts "$train_subset_feats" \
       "ark,s,cs:gunzip -c $dir/ali_special.gz | ali-to-pdf $alidir/final.mdl ark:- ark:- | ali-to-post ark:- ark:- |" \
       "ark:$dir/egs/train_subset_all.egs" || touch $dir/.error &
    wait;
    [ -f $dir/.error ] && echo "Error detected while creating train/valid egs" && exit 1
    echo "Getting subsets of validation examples for diagnostics and combination."
    $cmd $dir/log/create_valid_subset_combine.log \
      nnet-subset-egs --n=$num_valid_frames_combine ark:$dir/egs/valid_all.egs \
          ark:$dir/egs/valid_combine.egs || touch $dir/.error &
    $cmd $dir/log/create_valid_subset_diagnostic.log \
      nnet-subset-egs --n=$num_frames_diagnostic ark:$dir/egs/valid_all.egs \
      ark:$dir/egs/valid_diagnostic.egs || touch $dir/.error &
  
    $cmd $dir/log/create_train_subset_combine.log \
      nnet-subset-egs --n=$num_train_frames_combine ark:$dir/egs/train_subset_all.egs \
      ark:$dir/egs/train_combine.egs || touch $dir/.error &
    $cmd $dir/log/create_train_subset_diagnostic.log \
      nnet-subset-egs --n=$num_frames_diagnostic ark:$dir/egs/train_subset_all.egs \
      ark:$dir/egs/train_diagnostic.egs || touch $dir/.error &
    wait
    cat $dir/egs/valid_combine.egs $dir/egs/train_combine.egs > $dir/egs/combine.egs
  
    for f in $dir/egs/{combine,train_diagnostic,valid_diagnostic}.egs; do
      [ ! -s $f ] && echo "No examples in file $f" && exit 1;
    done
    rm $dir/egs/valid_all.egs $dir/egs/train_subset_all.egs $dir/egs/{train,valid}_combine.egs $dir/ali_special.gz
  fi
  
  if [ $stage -le 3 ]; then
    # Other scripts might need to know the following info:
    echo $num_jobs_nnet >$dir/egs/num_jobs_nnet
    echo $iters_per_epoch >$dir/egs/iters_per_epoch
    echo $samples_per_iter_real >$dir/egs/samples_per_iter
  
    echo "Creating training examples";
    # in $dir/egs, create $num_jobs_nnet separate files with training examples.
    # The order is not randomized at this point.
  
    egs_list=
    for n in `seq 1 $num_jobs_nnet`; do
      egs_list="$egs_list ark:$dir/egs/egs_orig.$n.JOB.ark"
    done
    echo "Generating training examples on disk"
    # The examples will go round-robin to egs_list.
    $cmd $io_opts JOB=1:$nj $dir/log/get_egs.JOB.log \
      nnet-get-egs $ivectors_opt $nnet_context_opts "$feats" \
      "ark,s,cs:gunzip -c $alidir/ali.JOB.gz | ali-to-pdf $alidir/final.mdl ark:- ark:- | ali-to-post ark:- ark:- |" ark:- \| \
      nnet-copy-egs ark:- $egs_list || exit 1;
  fi
  
  if [ $stage -le 4 ]; then
    echo "$0: rearranging examples into parts for different parallel jobs"
    # combine all the "egs_orig.JOB.*.scp" (over the $nj splits of the data) and
    # then split into multiple parts egs.JOB.*.scp for different parts of the
    # data, 0 .. $iters_per_epoch-1.
  
    if [ $iters_per_epoch -eq 1 ]; then
      echo "$0: Since iters-per-epoch == 1, just concatenating the data."
      for n in `seq 1 $num_jobs_nnet`; do
        cat $dir/egs/egs_orig.$n.*.ark > $dir/egs/egs_tmp.$n.0.ark || exit 1;
        remove $dir/egs/egs_orig.$n.*.ark
      done
    else # We'll have to split it up using nnet-copy-egs.
      egs_list=
      for n in `seq 0 $[$iters_per_epoch-1]`; do
        egs_list="$egs_list ark:$dir/egs/egs_tmp.JOB.$n.ark"
      done
      # note, the "|| true" below is a workaround for NFS bugs
      # we encountered running this script with Debian-7, NFS-v4.
      $cmd $io_opts JOB=1:$num_jobs_nnet $dir/log/split_egs.JOB.log \
        nnet-copy-egs --random=$random_copy --srand=JOB \
          "ark:cat $dir/egs/egs_orig.JOB.*.ark|" $egs_list || exit 1;
      remove $dir/egs/egs_orig.*.*.ark  2>/dev/null
    fi
  fi
  
  if [ $stage -le 5 ]; then
    # Next, shuffle the order of the examples in each of those files.
    # Each one should not be too large, so we can do this in memory.
    echo "Shuffling the order of training examples"
    echo "(in order to avoid stressing the disk, these won't all run at once)."
  
    for n in `seq 0 $[$iters_per_epoch-1]`; do
      $cmd $io_opts JOB=1:$num_jobs_nnet $dir/log/shuffle.$n.JOB.log \
        nnet-shuffle-egs "--srand=\$[JOB+($num_jobs_nnet*$n)]" \
        ark:$dir/egs/egs_tmp.JOB.$n.ark ark:$dir/egs/egs.JOB.$n.ark
      remove $dir/egs/egs_tmp.*.$n.ark
    done
  fi
  
  echo "$0: Finished preparing training examples"