#!/bin/bash
  
  # Copyright 2012  Johns Hopkins University (Author: Daniel Povey).  Apache 2.0.
  
  # Combine two decoding directories by composing the lattices (we
  # apply a weight to each of the original weights, by default 0.5 each).
  
  # Begin configuration section.
  weight1=0.5 # Weight on 1st set of lattices.
  cmd=run.pl
  # 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_combine.sh [options] <data> <lang-dir|graph-dir> <decode-dir1> <decode-dir2> <decode-dir-out>"
    echo " e.g.: steps/decode_combine.sh data/lang data/test exp/dir1/decode exp/dir2/decode exp/combine_1_2/decode"
    echo "main options (for others, see top of script file)"
    echo "  --config <config-file>                   # config containing options"
    echo "  --cmd <cmd>                              # Command to run in parallel with"
    echo "  --weight1 <weight>                       # Weight on 1st set of lattices (default 0.5)"
    exit 1;
  fi
  
  data=$1
  lang_or_graphdir=$2
  srcdir1=$3
  srcdir2=$4
  dir=$5
  
  for f in $data/utt2spk $lang_or_graphdir/phones.txt $srcdir1/lat.1.gz $srcdir2/lat.1.gz; do
    [ ! -f $f ] && echo "$0: no such file $f" && exit 1;
  done
  
  nj1=`cat $srcdir1/num_jobs` || exit 1;
  nj2=`cat $srcdir2/num_jobs` || exit 1;
  [ $nj1 -ne $nj2 ] && echo "$0: mismatch in number of jobs $nj1 versus $nj2" && exit 1;
  nj=$nj1
  
  mkdir -p $dir/log
  echo $nj > $dir/num_jobs
  
  # The lattice-interp command does the score interpolation (with composition),
  # and the lattice-copy-backoff replaces the result with the 1st lattice, in 
  # cases where the composed result was empty.
  $cmd JOB=1:$nj $dir/log/interp.JOB.log \
    lattice-interp --alpha=$weight1 "ark:gunzip -c $srcdir1/lat.JOB.gz|" \
     "ark,s,cs:gunzip -c $srcdir2/lat.JOB.gz|" ark:- \| \
    lattice-copy-backoff "ark,s,cs:gunzip -c $srcdir1/lat.JOB.gz|" ark,s,cs:- \
     "ark:|gzip -c >$dir/lat.JOB.gz" || exit 1;
  
  [ ! -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 $lang_or_graphdir $dir
  
  exit 0;