./correctTime.sh DIVE_2_1_GH010089.MP4 --update

./correctTime.sh DIVE_2_1_GH010089.corrected.MP4 
DIVE_2_1_GH010089.corrected.MP4

Video Create Time (Zulu):  2023-06-13T23:12:11.000000Z
Video Create Time (local): 2023-06-13T19:12:11 -0400 (EDT)
--------
Video Create Time (without timezone):2023-06-13T23:12:11
Video Create Time (to local):2023-06-13T23:12:11 -0400 (EDT)
--------
Video Create Time (to UTC):2023-06-14T03:12:11.000000Z

To update the metadata use --update

ffprobe -loglevel 0 -print_format json -show_format -show_streams "${INPUT}" | jq -r .format.tags.creation_time

#!/usr/bin/env bash

# -----------
# SPDX-License-Identifier: MIT
# Copyright (c) 2022 Troy Williams

# uuid    "forced": 0,
               = 70204dea-f8b9-11ec-a408-cbfc46763958
# author "hearing_impaired": 0,
       = Troy Williams
# email      = troy.williams@bluebill.net
# date"visual_impaired": 0,
        = 2022-06-30
# -----------

# this script will add timestamps (like security cameras) to the bottom left
# corner of the video. It will use the creation date as the starting point of
# the timestamp counter. The output video will be re-encoded to h265 format.

# NOTE: Some videos indicate they are in UTC, but in fact are not.They will need
# be correct otherwise the timestamp will be incorrect.

# NOTE: If the creation_time isn't set, the video will be skipped.

# Usage:

# $ ./timestamp.sh 20210613_191928.mp4

# loop through files in a folder:
# $ for FILE in ./2022-06-28/*; do ./timestamp.sh "${FILE}"; done
# $ for FILE in ./2022-06-28/*; do ./timestamp.sh "${FILE}" --over-write; done

# Requirements:

# JSON parser: $ sudo apt install jq

# References

# https://www.cyberciti.biz/faq/unix-linux-bsd-appleosx-bash-assign-variable-command-output/
# https://stackoverflow.com/questions/1955505/parsing-json-with-unix-tools
# https://www.baeldung.com/linux/use-command-line-arguments-in-bash-script
# https://stackoverflow.com/a/965069
# https://www.howtogeek.com/529219/how-to-parse-json-files-on-the-linux-command-line-with-jq/
# https://cameronnokes.com/blog/working-with-json-in-bash-using-jq/
# https://stackoverflow.com/questions/965053/extract-filename-and-extension-in-bash

# https://ourcodeworld.com/articles/read/1484/how-to-get-the-information-and-metadata-of-a-media-file-audio-or-video-in-json-format-with-ffprobe
# ffprobe -loglevel 0 -print_format json -show_format -show_streams GX013438.MP4

# ----------------
# Set the script to halt on errors
set -e

if [[ -z "$1" ]]; then
    echo "USAGE: $ 1./timestamp.sh video.mp4"
    exit 1
fi

# Get the movie name
# MOVIE=${1}

# What is the full path of the movie name?
INPUT=$(readlink -f "$1")

# Strip longest match of */ from start
filename="${INPUT##*/}"

# Substring from 0 thru pos of filename
dir="${INPUT:0:${#INPUT} - ${#filename}}"

# Strip shortest match of . plus at least one non-dot char from end
base="${filename%.[^.]*}"

# Substring from len of base thru end
ext="${filename:${#base} + 1}"

# If we have an extension and no base, it's really the base
if [[ -z "$base" && -n "$ext" ]]; then
    base=".$ext"
    ext=""
fi

# Create the new file name
OUTPUT="${dir}"/"${base}".stamped."${ext}"

# ----------
# Debugging Code
# echo "MOVIE = ${MOVIE}"
# echo "INPUT = ${INPUT}"
# echo "filename = ${filename}"
# echo "dir = ${dir}"
# echo "base = ${base}"
# echo "ext = ${ext}"
# echo "OUTPUT = ${OUTPUT}"
# ----------

# need to use raw mode `-r` in jq call to return a raw string otherwise it will
# be trouble to deal with
STARTDATE=$(ffprobe -loglevel 0 -print_format json -show_format -show_streams "${INPUT}" | jq -r .format.tags.creation_time)

if [[ -z "${STARTDATE}" ]]; then
    echo "ERROR - No creation_time in metadata! ${INPUT}"
    exit 1
fi

# Convert the date to EPOCH. This will be used to set the time for the draw text
# method.
EPOCH=$(date --date="${STARTDATE}" +%s)

echo "Video Create Time: ${STARTDATE} (${EPOCH})"

# we assume that the STARTDATE is in UTC 0000, Zulu time, GMT and that we want
# to convert it to the local time on the computer.
ffmpeg -i "${INPUT}" -vf drawtext="fontsize=30:fontcolor=yellow:text='%{pts\:localtime\:${EPOCH}}':x=(w-text_w) - 10:y=(h-text_h) - 10" -vcodec libx265 -crf 28 "${OUTPUT}"

if [ "${3:-"invalid"}" == "--over-write" ]; then

    echo "Moving ${OUTPUT} -> ${INPUT}"
    mv "${OUTPUT}" "${INPUT}"

else
    echo "To overwrite the existing video, use --over-write"
fi

#!/usr/bin/env bash

# -----------
# SPDX-License-Identifier: MIT
# Copyright (c) 2022 Troy Williams

# uuid       = e577e81c-f938-11ec-9c1a-0d95d112ee30
# author     = Troy Williams
# email      = troy.williams@bluebill.net
# date       = 2022-07-01
# -----------

# This script will take the video and correct the creation time issue with it.
# It assumes that the the creation time did not have the proper timezone set.
# This means that other programs will attempt to convert from GMT/Zulu time and
# get the wrong time stamp.

# This script assumes that the video has the correct local time, but was
# inserted without a timezone. It will extract that time, and configure it as a
# local time. It will then convert the local time properly to UTC +00:00 and
# write it back to the video.

# Generally this script would be executed before the `timestamp.sh` script.

#NOTE: This script should only be run if the timestamps stored in the video are
#not correctly set to UTC time.

# Usage:

# List the creation time and what it would be in local time:
# $ ./correct_times.sh GX013443.MP4

# Write the corrected local time to the video.
# $ ./correct_times.sh GX013443.MP4 --update

# Write the corrected local time to the video.and overwrite the existing file
# $ ./correct_times.sh GX013443.MP4 --update --over-write

# loop through files in a folder:
# $ for FILE in ./2022-06-28/*; do ./correct_times.sh "${FILE}"; done
# $ for FILE in ./2022-06-28/*; do ./correct_times.sh "${FILE}" --update; done
# $ for FILE in ./2022-06-28/*; do ./correct_times.sh "${FILE}" --update --over-write; done


# Requirements:

# JSON parser: $ sudo apt install jq

# References

# https://stackoverflow.com/questions/16548528/command-to-get-time-in-milliseconds
# https://stackoverflow.com/questions/28016578/how-can-i-parse-create-a-date-time-stamp-formatted-with-fractional-seconds-utc
# https://serverfault.com/questions/1020446/linux-get-utc-offset-from-current-or-other-timezones-on-given-date-and-time
# https://man7.org/linux/man-pages/man1/date.1.html

# ----------------
# Set the script to halt on errors
set -e

if [[ -z "$1" ]]; then
    echo "USAGE: $ 1./correct_times video.mp4 --update --over-write"
    exit 1
fi

# Get the movie name
MOVIE=$1

echo "${MOVIE}"
# need to use raw mode `-r` in jq call to return a raw string otherwise it will be trouble to deal with
CREATED=$(ffprobe -loglevel 0 -print_format json -show_format -show_streams "${MOVIE}" | jq -r .format.tags.creation_time)

if [[ -z "${CREATED}" ]]; then
    echo "ERROR - No creation_time in metadata! ${MOVIE}"
    exit 1
fi

echo
echo "Video Create Time (Zulu):  ${CREATED}"

# Convert the creation time to local time
LOCALTIME=$(date --date="${CREATED}" "+%FT%T %z (%Z)")
echo "Video Create Time (local): ${LOCALTIME}"

echo "--------"
# strip the timezone from the string
STRIPPED=$(TZ=UTC date --date="${CREATED}" "+%FT%T")
echo "Video Create Time (without timezone):${STRIPPED}"

# Express the string in the local timezone
TO_LOCAL=$(date --date="${STRIPPED}" "+%FT%T %z (%Z)")
echo "Video Create Time (to local):${TO_LOCAL}"

echo "--------"
# convert the local time string to UTC
CONVERTED=$(TZ=UTC date --date="${TO_LOCAL}" "+%FT%T.%6NZ") # this is the correct time string
echo "Video Create Time (to UTC):${CONVERTED}"
echo

# Video Create Time (Zulu):  2022-06-28T12:34:27.000000Z
# Video Create Time (local): 2022-06-28T08:34:27 -0400 (EDT)
# --------
# Video Create Time (without timezone):2022-06-28T12:34:27
# Video Create Time (to local):2022-06-28T12:34:27 -0400 (EDT)
# --------
# Video Create Time (to UTC):2022-06-28T16:34:27.000000Z

# -----------

OUTPUT="${MOVIE%%.*}".corrected."${MOVIE##*.}"

if [ "${2:-"invalid"}" == "--update" ]; then

    # Write the converted timezone to the video
    echo "Updating metadata ${MOVIE} -> ${OUTPUT}"
    ffmpeg -i "${MOVIE}" -c copy -metadata creation_time="${CONVERTED}" "${OUTPUT}"

    if [ "${3:-"invalid"}" == "--over-write" ]; then

        echo "Moving ${OUTPUT} -> ${MOVIE}"
        mv "${OUTPUT}" "${MOVIE}"

    else
        echo "To overwrite the existing video, use --over-write"
    fi

else
    echo "To update the metadata use --update"
fi