convert

#!/bin/bash
# Converts audio formats in bulk
# requires avconv
fformat=m4a
tformat=mp3

c=0
t=0
files=*.$fformat

echo Scanning directory . . .

for file in $files; do
  t=$[t+1]
  echo "#$t: $file"
done

echo "Found $t file(s):"

read -p "Do you want to see avconv's output? (y/n) (default: n)" avcout

for file in $files; do
  fname="${file%.*}"
  c=$[c+1]
  echo "Converting ($c/$t)"
  echo "From: $fname.$fformat"
  echo "To:   $fname.$tformat"
  if [ "$avcout" == "y" ]; then
    avconv -i "$fname.$fformat" "$fname.$tformat"
  else
    avconv -i "$fname.$fformat" "$fname.$tformat" 2> /dev/null
  fi  
done

read -p "Do you want to keep all .$fformat files (0), remove them (1), or something else (2)? (default: 0)" choice

if [ "$choice" == "1" ]; then
  rm *.$fformat
elif [ "$choice" == "2" ]; then
  rm -i *.$fformat
fi