Bash script to measure length (duration) of media files in a directory

media-length.sh

#!/bin/bash -e

directory=$1
[ -z "$directory" ] || directory=`pwd`

total=0

function round_float {
    echo "($1 + 0.5)/1" | bc
}

function print_duration {
    local duration="$1"
    local days=$((duration/60/60/24))
    local hours=$((duration/60/60%24))
    local minutes=$((duration/60%60))
    local seconds=$((duration%60))
    [[ $days > 0 ]] && printf '%d days ' $days
    [[ $hours > 0 ]] && printf '%d hours ' $hours
    [[ $minutes > 0 ]] && printf '%d minutes ' $minutes
    [[ $days > 0 || $hours > 0 || $minutes > 0 ]] && printf 'and '
    printf '%d seconds\n' $seconds
}

function is_media_file {
    local file="$1"
    file --mime-type --brief "$file" | grep "audio\|video" > /dev/null
}

function process_media {
    local file="$1"
    local length=`avprobe -loglevel error -show_streams "$file" | grep duration= | cut -f2 -d= | sort --reverse | head -n1`
    
    if [[ "$length" != "" ]] && [[ "$length" != "N/A" ]] && [[ "$length" != "0" ]]; then
        total=`echo "scale=8;$total + $length" | bc`
        length=`round_float "$length"`
        echo -e "$file\n\t" $(print_duration "$length") "\t($length seconds)"
    fi
}

while read file; do
    file=`readlink -f "$file"`
    if is_media_file "$file"; then
        process_media "$file"
    fi
done < <(find "$1" -type f)

echo -e "\e[1mTotal\e[0m\n\t" $(print_duration "$(round_float $total)")