Add a script that renames all photo's and movies in a dir to date/time.

When photo's and movies from multiple sources are thrown in one dir it
often becomes a mess of different file formats. Also it's impossible to
view the images in chronological order. Very annoying when it's hundreds
of holiday photo's of both my wife and me.
This script searches for information about the date/time the photo/movie
was taken/shot and renames the file to `date_time.ext`.

Author: aswen

order_photos_by_exif_date

@@ -0,0 +1,146 @@
+#!/bin/bash
+# order_photos_by_exif_date
+
+# When photo's from multiple sources are thrown into one directory it might
+# very well happen that the filenames screw the order. You see the serie of
+# camera one first, then the other.
+
+# This renames all photo's to YYYYMMDD_HHMMSS.SubSec_DESCRIPTION_###.jpg by using the date from exif
+# information.
+#
+# The ### part is an optional random 3 digit number. If multiple photo's are
+# taken on the same time the serial will be incremented.
+
+# CHANGELOG:
+# 2019-10-04 A.Swen	created.
+
+# SETTINGS
+date=$(date +%Y%m%d)
+me=$(basename $0)
+mydir=$(dirname $0)
+
+# FUNCTIONS
+die () {
+  rc=$1
+  shift
+  printf '%s\n' "=====================" >&2
+  printf '%s\n' "==== FATAL ERROR ====" >&2
+  printf '%s\n\n' "=====================" >&2
+  printf '%s\n\n' "$@" >&2
+  exit $rc
+}
+
+usage () {
+  printf '%s\n' "===============" >&2
+  printf '%s\n' "==== USAGE ====" >&2
+  printf '%s\n\n' "===============" >&2
+  printf '%s\n' "Usage: ${me} [-d|--directory <directory>] [-D|--description <description>]" >&2
+  printf '%s\n\n' "example: ${me} " >&2
+  printf '%s\n\n' "example: ${me} -d /data/foto/bla -D 'A night at the opera'" >&2
+  exit 1
+}
+get_options () {
+  while [[ $# -gt 0 ]]; do
+    case "$1" in
+      --directory|-d)
+        shift
+        declare -r directory="$1"
+        shift
+        ;;
+      --description|-D)
+        shift
+        declare -r description="_${1}"
+        shift
+        ;;
+      -h|--help)
+        usage
+        ;;
+      *)
+        usage
+        ;;
+    esac
+  done
+}
+
+log () { printf '%s %s\n' "$(date +%F' '%T)" "$@"; }
+
+# SCRIPT
+log "Started ${me}"
+
+# Without exiftool we can't do much
+which exiftool 2>&1 > /dev/null || die 1 "Exiftool not found"
+which ffprobe 2>&1 > /dev/null || die 1 "Ffprobe not found"
+unset directory description
+
+if [[ $# -gt 0 ]];then
+  get_options
+fi
+[ -z "$directory" ] && directory="$(pwd)"
+[ -d "$directory" ] || die 2 "Directory '$directory' not found"
+
+find "$directory" -iname \*.jpg -o -iname \*.jpeg -o -iname \*.dng -o -iname \*.mp4|while read original_filename;do
+
+  unset create_date_time
+
+  # Try to get the date/time from the file.
+  case $original_filename in
+    *.jpg|*.JPG|*.jpeg)
+      create_date_time=$(exiftool -S -SubSecCreateDate "$original_filename"|sed -e 's?SubSecCreateDate: ??g' -e 's?:??g' -e 's? ?_?' -e 's?\.?_?g')
+      if [ -z "$create_date_time" ];then
+        # Try the DateTimeOriginal field
+        create_date_time=$(exiftool -S -DateTimeOriginal "$original_filename"|sed -e 's?DateTimeOriginal: ??g' -e 's?:??g' -e 's? ?_?' -e 's?\.?_?g')
+      fi
+      if [ -z "$create_date_time" ];then
+        # Try the GPSDateTime field
+        unset gps_date_time
+        gps_date_time=$(exiftool -S -GPSDateTime "$original_filename"|sed -e 's?GPSDateTime: ??' -e 's?:?-?' -e 's?:?-?'  -e 's? ?T?')
+        if [ -n "$gps_date_time" ];then
+          create_date_time=$(date -d "$gps_date_time" +%Y%m%d_%H%M%S)
+        fi
+      fi
+      if [ -z "$create_date_time" ];then
+        # Try the FileModifyDate field
+        file_modify_date=$(exiftool -S -FileModifyDate "$original_filename"|sed -e 's?FileModifyDate: ??' -e 's?:?-?' -e 's?:?-?')
+        if [ -n "$file_modify_date" ];then
+          create_date_time=$(date -d "$file_modify_date" +%Y%m%d_%H%M%S)
+        fi
+      fi
+      ext=jpg
+    ;;
+    *.dng|*.DNG)
+      create_date_time=$(exiftool -S -DateTimeOriginal "$original_filename"|sed -e 's?DateTimeOriginal: ??g' -e 's?:??g' -e 's? ?_?' -e 's?\.?_?g') || die 4 "exiftool failed on $original_filename"
+      ext=dng
+    ;;
+    *.mp4|*MP4)
+      create_date_time=$(date -d $(ffprobe "$original_filename" 2>&1 |grep creation_time|head -1|sed -e 's?\s\+creation_time\s\+:\s\+??') +%Y%m%d_%H%M%S)||die 5 "Cannot get creation_time from file $original_filename".
+      ext=mp4
+    ;;
+    *)
+      log "I don't know how to get a date from $original_filename"
+      continue
+    ;;
+  esac
+
+  # If no create_date_time can be extracted we can't do much more.
+  if [ -z "$create_date_time" ];then
+    fn=$(basename "$original_filename")
+    log "Can't find a date/time for $fn. We don't change it."
+    unset fn
+    continue
+  fi
+
+  # With the information we have we can construct a new filename
+  new_filename="$directory/${create_date_time}${description}.$ext"
+
+  # Check for duplicates. Should there be one: add a random number.
+  until [ ! -f "$new_filename" ];do
+    log "$new_filename exists, choosing new random serial."
+    new_filename="$directory/${create_date_time}${description}_$((RANDOM % 999)).$ext"
+  done
+
+  # Rename the file.
+  echo Renaming \"$(basename "$original_filename")\" to \"$(basename "$new_filename")\"
+  mv "$original_filename" "$new_filename"
+done
+
+# END