sets a video's encode date by using the file's mtime

encode-date-from-mtime.sh

#!/bin/bash
# sets a video's encode date by using the file's mtime
# requires mediainfo and ffmpeg
# see also the inverse of this script: "mtime-from-encode-date.sh"
# https://gist.github.com/yoosefi/3d5841e0c2b71edf02eec0730249128f
set -eu
for each in "$@"; do
    x=($(mediainfo "${each}" | grep 'Encoded date'))
    # only remux if the date is bogus
    if [[ "${x}" == "" || "${x[4]}" =~ ^19[0-8].* ]]; then
        MTIME=$(date --iso-8601=seconds -r "${each}")
        mv "${each}" "${each}.old"
        TZ=UTC ffmpeg -i "${each}.old" -c copy -map_metadata 0 -metadata creation_time="${MTIME}" "${each}"
        touch -d "${MTIME}" "${each}"
        rm "${each}.old"
    fi
done