bashplaylist - extm3u playlist maker

#!/bin/bash
#Dependencies: usual gnu utils, ffmpeg or ffprobe

##june 07 2012 edited to remove unwanted \ in regex expression which ###prevented ogg files from being parsed.

function usage ()
{
    printf "\nUSAGE:
\t$(basename "$0") [options] {-o out} <directory>\n
OPTIONS:
\t-p  writes the file names in .m3u with full path\n\
\t    (default is simple file name without path)\n
\t-r  recurses through subdirectories and writes file names with
\t    full path\n
\t-o <output directory>  (default is target directory)\n
\t$(basename "$0") finds the audio files in the directory, parses
\tthe metadata, then writes an extended .m3u playlist\n
\t$(basename "$0") understands the same files as  your
\tinstalled version of ffmpeg.\n
\tIf $(basename "$0") fails please check output directory exists
\tand is writeable.\n\n"
}

#dump file data;grep metadata relevant to extm3u.
#extm3u spec states that stated time MUST be equal to or greater than
#track duration so all times are rounded UP to integer i.e. 38.00 secs
#becomes 38 seconds but 38.10 secs or 38.95 seconds become 39 seconds.
function getdata ()
{
ffprobe -show_format "$f">"$DATA"

PERF=$(grep -m 1 -i tag:artist "$DATA" |\
awk -F "=" '{$1="";$0=substr($0,2)}1' |cleantag)
TIT=$(grep -m 1 -i tag:title "$DATA" |\
awk -F "=" '{$1="";$0=substr($0,2)}1' |cleantag)
SEC=$(printf %.2f\\n $(grep -m 1 -i -e "^duration" "$DATA" |\
awk -F "=" '{print $2}'))
SEC=$(printf %0.f\\n $(echo "$SEC+0.5"|bc))
}

#remove problematic characters from metadata.
function cleantag ()
{
    sed 's/[;]/-/g;s/[/]/-/g;s/[<]/-/g;s/[>]/-/g;s/[:]/-/g;s/[|]/-/g'
}

#user options
while getopts 'o:pr' OPTION
do
    case $OPTION in
    o)  oflag=1
        oval=$OPTARG
        ;;
    p)  pflag=1
        ;;
    r)  rflag=1
        pflag=1
        ;;
    esac
done
shift $(($OPTIND-1))

if [ $# -lt 1 ]; then
    usage
    exit 1
fi

#recurse?
if [ $rflag ]; then
    DEPTH=''
    else
    DEPTH="-maxdepth 1"
fi

for i in "$@" ; do
#ensure .m3u name is not dot file if script run within target directory.
PN=$(basename "$(readlink -f "$i")").m3u

#some simple error checking
if [ ! -d "$i" ]; then
    usage
    exit
fi

#set output destination. Output dir exists and writeable?
if [ $oflag ]; then
    if [ ! -d "$oval" -o ! -w "$oval" ]; then
    usage
    exit
    fi
    PL=$oval/"$PN"
    else
    PL="$i"/"$PN"
fi

#create/overwrite .m3u and write extm3u's generic 1st line
printf "#EXTM3U">"$PL"

#find all audio files to be referenced in .m3u
find "$i" $DEPTH -iregex ".*\(flac\|ape\|wv\|wav\|mpc\|aac\|m4a\|wma\|\
mp3\|ogg\|oga\|mka\|ac3\)$" |sort |while read f ; do

#use full path or simple names?
if [ $pflag ]; then
    FILENAME=$(readlink -f "$f")
    else
    FILENAME="${f##*/}"
fi

#where to dump ffprobe's file info
DATA="${f%.*}"_data

#run getdata silently (ffprobe generates much unwanted text)
getdata>/dev/null 2>&1

#write to the playlist, clean up.
printf "\n#EXTINF:$SEC,$PERF - $TIT\n$FILENAME">>"$PL"
rm "$DATA"
done

#confirm to user, quit.
echo "Wrote "$PL""
done
exit 0