Recursive converter using ffmpeg (example uses flac -> m4a/alac)

reconvert.sh

#!/bin/bash
# assembled & improved by mia-cx
# sources used:
# - https://superuser.com/a/1307579
# - https://stackoverflow.com/a/31605674
# - https://stackoverflow.com/a/965072

# read relative "working" directory
read -e -p "Working directory: " -i "./" RELDIR

# set working directory
PWD="$(
    cd "$(dirname "$DIR")"
    pwd
)"
# echo $PWD

# what files should be processed
read -e -p "Input pattern: " -i ".flac" PATTERN
# what is the output format
read -e -p "Output extension: " -i ".m4a" EXTENSION
read -e -p "Output codec: " -i "alac" CODEC

# marker will be appended to files that have been processed,
# so that the script won't process them more than once
MARKER="formats"

echo -n "Finding candidate files .."
FILELIST=$(find "$PWD" -type f -name "*$PATTERN")
echo ".. "$(echo -e "$FILELIST" | wc -l)" found"
# echo "$FILELIST"

while read FILEPATH; do
    # A bit of healthy paranoia
    test -z "$FILEPATH" && continue
    test -f "$FILEPATH" || continue
    echo "Working on $FILEPATH .."

    # New file name
    FILENAME=$(basename -- "$FILEPATH")
    INPUTEXTENSION="${FILENAME##*.}"
    FILENAME="${FILENAME%.*}"
    #   echo $FILENAME
    #   echo $INPUTEXTENSION
    #   echo $EXTENSION
    BP=$(dirname "$FILEPATH")
    NBP=${BP#$PWD/}
    NEWFILEPATH="$PWD/$MARKER/$EXTENSION/$NBP/$FILENAME$EXTENSION"
    # echo $NEWFILEPATH 

    # Skip result files
    ISRESULT=$(echo "$FILEPATH" | grep -e "/$MARKER/")
    if test -n "$ISRESULT"; then
        echo "..  skipping (is a result file)"
        continue
    fi
    
    # Skip untagged
    ISUNTAGGED=$(echo "$FILEPATH" | grep "/untagged/")
    if test -n "$ISUNTAGGED"; then
        echo "..  skipping (is an untagged file)"
        continue
    fi

    # Skip processed files
    if test -f "$NEWFILEPATH"; then
        echo "..  skipping (result file exists)"
        continue
    fi

    # create marker directory
    mkdir -p "$PWD/$MARKER/$EXTENSION/$NBP"

    # Process
    echo -n ".. running ffmpeg .."
    RES=$(ffmpeg -loglevel info -y -i "$FILEPATH" -c:a $CODEC -c:v copy "$NEWFILEPATH" </dev/null 2>&1)
    # echo $RES
    echo ".. done (exit code $?)"

done < <(echo -e "$FILELIST")