#!/usr/bin/env sh

# Description: Create an mp3 ringtone out of an audio file in any format
#              Needs user to provide start and end where to cut the file
#              Input file audio.ext results in audio_ringtone.mp3
#
#              Tip: To convert a complete media file, set start as 0 and
#              the runtime of the file as end.
#
# Dependencies: date, ffmpeg
#
# Shell: POSIX compliant
# Author: Arun Prakash Jana

if [ -n "$1" ]; then
    printf "start (hh:mm:ss): "
    read -r start
    st=$(date -d "$start" +%s) || exit 1

    printf "end (hh:mm:ss): "
    read -r end
    et=$(date -d "$end" +%s) || exit 1

    if [ "$st" -ge "$et" ]; then
        printf "error: start >= end "
        read -r _
        exit 1
    fi

    interval=$(( et - st ))

    outfile=$(basename "$1")
    outfile="${outfile%.*}"_ringtone.mp3

    ffmpeg -i "$1" -ss "$start" -t "$interval" -vn -sn -acodec libmp3lame -q:a 2 "$outfile"
fi