#!/bin/bash 

# Copyright 2012  Johns Hopkins University (Author: Daniel Povey)
# Apache 2.0
# To be run from .. (one directory up from here)
# see ../run.sh for example

# Compute cepstral mean and variance statistics per speaker.  
# We do this in just one job; it's fast.
# This script takes no options.
#
# Note: there is no option to do CMVN per utterance.  The idea is
# that if you did it per utterance it would not make sense to do
# per-speaker fMLLR on top of that (since you'd be doing fMLLR on
# top of different offsets).  Therefore what would be the use
# of the speaker information?  In this case you should probably
# make the speaker-ids identical to the utterance-ids.  The
# speaker information does not have to correspond to actual
# speakers, it's just the level you want to adapt at.

echo "$0 $@"  # Print the command line for logging

fake=false
if [ $1 == "--fake" ]; then
  fake=true
  shift
fi

if [ $# != 3 ]; then
   echo "usage: compute_cmvn_stats.sh [--fake] <data-dir> <log-dir> <path-to-cmvn-dir>";
   echo "(note: --fake gives you fake cmvn stats that do no normalization.)"
   exit 1;
fi

if [ -f path.sh ]; then . ./path.sh; fi

data=$1
logdir=$2
cmvndir=$3

# make $cmvndir an absolute pathname.
cmvndir=`perl -e '($dir,$pwd)= @ARGV; if($dir!~m:^/:) { $dir = "$pwd/$dir"; } print $dir; ' $cmvndir ${PWD}`

# use "name" as part of name of the archive.
name=`basename $data`

mkdir -p $cmvndir || exit 1;
mkdir -p $logdir || exit 1;


required="$data/feats.scp $data/spk2utt"

for f in $required; do
  if [ ! -f $f ]; then
    echo "make_cmvn.sh: no such file $f"
    exit 1;
  fi
done

if $fake; then
  dim=`feat-to-dim scp:$data/feats.scp -`
  ! cat $data/spk2utt | awk -v dim=$dim '{print $1, "["; for (n=0; n < dim; n++) { printf("0 "); } print "1";
                                                        for (n=0; n < dim; n++) { printf("1 "); } print "0 ]";}' | \
    copy-matrix ark:- ark,scp:$cmvndir/cmvn_$name.ark,$cmvndir/cmvn_$name.scp && \
     echo "Error creating fake CMVN stats" && exit 1;
else  
  ! compute-cmvn-stats --spk2utt=ark:$data/spk2utt scp:$data/feats.scp ark,scp:$cmvndir/cmvn_$name.ark,$cmvndir/cmvn_$name.scp \
    2> $logdir/cmvn_$name.log && echo "Error computing CMVN stats" && exit 1;
fi

cp $cmvndir/cmvn_$name.scp $data/cmvn.scp || exit 1;

nc=`cat $data/cmvn.scp | wc -l` 
nu=`cat $data/spk2utt | wc -l` 
if [ $nc -ne $nu ]; then
  echo "Error: it seems not all of the speakers got cmvn stats ($nc != $nu);"
  exit 1;
fi

echo "Succeeded creating CMVN stats for $name"