Life, the Universe and Engineering…

#!/bin/bash

SCRIPT=`basename "$0"`
MKVMERGE=`which mkvmerge`
METAFLAC=`which metaflac`
FLAC=`which flac`
MKVEXTRACT=`which mkvextract`
startime=`date +%s`


#Set output directory to current
outdir="./"

#Check if arguments given, offer help
if [ "$1" == "" ] || [ "$1" == "--help" ] || [ "$1" == "-h" ]; then
    echo "$SCRIPT: Give MKV to chapter-split as an argument"
    echo "$SCRIPT: e.g.:  title00.mkv"
    echo "$SCRIPT: e.g.:  title01.mkv"
    exit 1
fi

#Check MKV file passed exists
if [ ! -f "$1" ]; then
    echo "$SCRIPT: MKV file not found [$1]"
    exit 1
fi    

#Set output directory to file name without extension
outdir="$1"
outdir=${outdir%.*}
echo "$SCRIPT: Output folder is "${outdir}""

#Check if folder already exists, create if not
if [ ! -d "$outdir" ]; then
       echo "$SCRIPT: The output directory ($outdir) does not exist, creating"
       mkdir "$outdir"
fi

#Check mkvtoonix is installed, offer help if not
if [ "$MKVMERGE" == "" ] || [ ! -x "$MKVMERGE" ]; then
    echo "$SCRIPT: 'mkvmerge' seems to be missing"
    echo "$SCRIPT: Is mkvtoolnix Installed?"
    echo "$SCRIPT: sudo apt-get install mkvtoolnix"
    exit 2
fi 

#Check if flac is installed, offer help if not
if [ "$METAFLAC" == "" ] || [ ! -x "$METAFLAC" ]; then
    echo "$SCRIPT: 'metaflac' seems to be missing"
    echo "$SCRIPT: Is flac installed?"
    echo "$SCRIPT: sudo apt-get install flac"
    exit 2
fi 

infile="$1"

#List audio streams from input file
"$MKVMERGE" -i "${infile}" | grep Track

#Ask user for track number to rip
unset get_track

while [[ ! ${get_track} =~ ^[0-9]+$ ]]; do
    echo "$SCRIPT: Enter number of track ID to rip"
    read get_track
done
    
echo "$SCRIPT: You selected track" ${get_track}

#Split MKV file into chapters
echo "$SCRIPT: Splitting video file into chapters"

"$MKVMERGE" --split chapters:all "${infile}" -o "${outdir}/${infile%.mkv}_%02d.mkv"

cd "${outdir}"

#Extract LPCM audio from renamed MKV chapter files

echo "$SCRIPT: Demuxing LPCM audio from MKV files"

for file in *.mkv
do
"$MKVEXTRACT" tracks "$file" $get_track:"${file%.*}".wav;

echo "$SCRIPT: Deleting source MKV file"

rm "${file}"
done

#Convert WAV files to FLAC
for file in *.wav
do
"$FLAC" --delete-input-file --best "$file";

echo "$SCRIPT: Converting WAV file to FLAC and deleting source file"
done

#Ask user for metadata for tagging with metaflac
echo "$SCRIPT: Please enter Artist name for tagging"
read artist
    while [ -z "$artist" ]; do
        echo "$SCRIPT: Entry was blank, please type an Artist name"
        read artist
    done
echo "$SCRIPT: Please enter Album name for tagging"
read album
    while [ -z "$album" ]; do
        echo "$SCRIPT: Entry was blank, please type an Album name"
        read album
    done
echo "$SCRIPT: Please enter Album year for tagging"
read year
    while [ -z "$year" ]; do
        echo "$SCRIPT: Entry was blank, please type an Album year"
        read year
    done
echo "$SCRIPT: Please enter Genre for tagging"
read genre
    while [ -z "$genre" ]; do
        echo "$SCRIPT: Entry was blank, please type a Genre"
        read genre
    done

#Reset track counter
track=0

#For each flac file, ask user for track name, rename file,
#add track number and add tags using metaflac
for file in *.flac
do
        ((track+=1))
        echo "$SCRIPT: Current file name: "${file%.*}""
        echo "$SCRIPT: Please enter new name"
        read newname
            while [ -z "$newname" ]; do
                echo "$SCRIPT: Entry was blank, please type a new name"
                read newname
            done
            echo "$SCRIPT: Renaming and tagging file"
            echo "$SCRIPT: $artist - $album - $track - $newname"
            mv "${file}" "$track - ${newname}.flac"
            #Remove all existing tags, just as a precaution, then add new ones
            "$METAFLAC" --remove-all-tags \
            --set-tag="ARTIST=$artist" \
            --set-tag="ALBUM=$album" \
            --set-tag="TITLE=$newname" \
            --set-tag="TRACKNUMBER=$track" \
            --set-tag="DATE=$year" \
            --set-tag="GENRE=$genre" \
            "$track - ${newname}.flac"
done

#Calculate and display script runtime 
endtime=`date +%s`
runtime=$((endtime - startime))
echo "$SCRIPT: All complete in $runtime seconds"