split (cut) video with MP4Box or ffmpeg as needed

split-video.sh

#!/bin/bash

if [ $# -lt 3 ]
then
    echo "Usage: ${0##*/} <filename> <fromtime [HH:]mm:ss> <totime [HH:]mm:ss> [suffix]"
    echo "   Ex: ${0##*/} INPUT.mp4 0:20 9:40 snip001"
    echo "   requires: gpac (MP4Box) and ffmpeg" 
else
    function to_sec() { echo "$1" | awk -F':' '{if (NF == 2) {print $1 * 60 + $2} else {print $1 * 60 * 60 + $2 * 60 + $3}}';}

    filename=$(basename -- "${1}")
    extension="${1##*.}"
    filename="${1%.*}"

    infile="${1}"
    if [ "$4" == "" ]
    then
        outfile="${filename}_cut.${extension}"
    else
        outfile="${filename}_cut_${4}.${extension}"
    fi

    if [ "${extension,,}" == "avi" ] ; then  ## if AVI case-insensitive
        nice -n 19 ffmpeg -ss $(to_sec ${2}) -i ${infile} -c copy -t $( expr $(to_sec ${3}) - $(to_sec ${2}) ) ${outfile}
    else
        nice -n 19 MP4Box -splitz $(to_sec "${2}"):$(to_sec "${3}") "${infile}" -out "${outfile}"
    fi
    touch "${outfile}" -r "${infile}"
fi