shotwell-thumbs

#!/bin/bash
#=======================================================================================================================
# Description
#   Script to (re)generate thumbnails for Shotwell
# Synopsis
#   shotwell-thumbs [options]
# Author
#   Dmitry Kann, https://yktoo.com/
# License
#   Public domain
#=======================================================================================================================

. "$(dirname "$(realpath "$0")")/common.sh"

# Setup vars
DB_FILE="$HOME/.local/share/shotwell/data/photo.db"
THUMB_BASE_DIR="$HOME/.cache/shotwell/thumbs/"
USAGE_INFO="Script for (re)generating Shotwell thumbnails. Written by Dmitry Kann, https://yktoo.com/

Usage: $0 [options]

Options:
  -h    Print out this help message and exit
  -r    Regenerate and overwrite thumbnail even if it exists
  -128  Generate 128x128 thumbnail
  -360  Generate 360x360 thumbnail

If neither -128 nor -360 is given, both sizes are generated."

# Get TTY width
tty_width=$(stty size | cut -d ' ' -f 2)

# Prints out a status message (overwritten every time)
# Arguments:
#   $1 message text
status() {
    # Pad/truncate the line to fit screen width
    printf "%-${tty_width}.${tty_width}s\r" "$1"
}

# Prints out a progress message
# Arguments:
#   $1 current item number
#   $2 total number of items
#   $3 message text
progress() {
    printf -v msg '[%d/%d] %s' "$1" "$2" "$3"
    status "$msg"
}

# Generates a thumbnail file
# Arguments:
#   $1 thumbnail size, either 128 or 360
#   $2 photo ID
#   $3 photo file name
#   $4 number of current photo
#   $5 total number of photos
# Returns:
#   Nonzero value if thumbnail generation was skipped
generate_thumb() {
    size="$1"
    id="$2"
    pic_file="$3"
    thumb_file=$(printf "$THUMB_BASE_DIR/thumbs${size}/thumb%016x.jpg" "$id")
    # If force regenerate or thumb file doesn't exist yet
    if ((regenerate != 0)) || [[ ! -f "$thumb_file" ]]; then
        progress "$4" "$5" "Generating $size thumbnail for $pic_file"
        convert "$pic_file" -auto-orient -thumbnail "${size}x${size}" "$thumb_file"
        if (($? != 0)); then
            status ""
            err "Generating thumbnail for $pic_file failed"
        fi
        return 0
    else
        progress "$4" "$5" "Skipping $size thumbnail for $pic_file"
        return 1
    fi
}

#-----------------------------------------------------------------------------------------------------------------------
# Main routine
#-----------------------------------------------------------------------------------------------------------------------

# Trap Ctrl-C
trap interrupted INT

# Validate paths
[[ -f "$DB_FILE" ]] || err "Shotwell database file $DB_FILE doesn't exist"
[[ -r "$DB_FILE" ]] || err "Shotwell database file $DB_FILE isn't readable"
[[ -d "$THUMB_BASE_DIR" ]] || err "Shotwell thumbnail base directory $THUMB_BASE_DIR doesn't exist"

# Parse the command line
regenerate=0
thumb128=
thumb360=
for arg; do
    case "$arg" in
        -h)
            usage
            ;;

        -r)
            regenerate=1
            ;;

        -128)
            thumb128=1
            ;;

        -360)
            thumb360=1
            ;;

        *)
            usage "Unknown option: '$arg'"
    esac
done

# If no size explicitly specified, activate both of them
if [[ -z "$thumb128" ]] && [[ -z "$thumb360" ]]; then
    thumb128=1
    thumb360=1
fi

# Get the total number of photos
count_total=$(sqlite3 "$DB_FILE" "select count(*) from PhotoTable")
((thumb128 != 0 && thumb360 != 0)) && ((count_total *= 2))

# Iterate over the files in reverse chronological order
count_cur=0
count_done=0
sqlite3 "$DB_FILE" "select id||' '||filename from PhotoTable order by timestamp desc" |
    while read pic_id pic_file; do
        ((thumb128 != 0)) && generate_thumb 128 "$pic_id" "$pic_file" "$((++count_cur))" "$count_total" && ((count_done++))
        ((thumb360 != 0)) && generate_thumb 360 "$pic_id" "$pic_file" "$((++count_cur))" "$count_total" && ((count_done++))
    done

echo
status "Done. $count_total thumbnails processed, $count_done thumbnails generated"
echo