A bash function (I keep it in my .bash_profile) for remuxing mkv files to mp4

gistfile1.sh

function mkv2mp4 {
        INPUT_FILE="$1"
        OUTPUT_FILE="${INPUT_FILE%.*}.mp4"

        if [[ "" == "${INPUT_FILE}" ]]; then echo "Usage: mkv2mp4 <file.mkv>" && return 1; fi
        if [[ ! -f "${INPUT_FILE}" ]]; then echo "Argument not a file." && return 1; fi
        if [[ -f "${OUTPUT_FILE}" ]]; then echo "Output file '$OUTPUT_FILE' already exists." && return 1; fi

        ffmpeg -vcodec copy -acodec copy -map_meta_data outfile:infile -i "${INPUT_FILE}" "${OUTPUT_FILE}"
}