Two scripts that accept two videos as input and outputs a collection of comparative thumbnails. The second iteration uses a faster method of taking screen grabs.

video_thumbnail_comparison.sh

#!/bin/bash

# Function to cleanup temporary files
cleanup() {
    echo "cleaning up"
    rm -rf tmp
}

# Function to get video duration
get_video_duration() {
    duration=$(ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 "$1" 2>/dev/null)
    if [ "$duration" != "N/A" ]; then
        # Calculate hours, minutes, and seconds
        hours=$(printf "%.0f" $(echo "$duration / 3600" | bc))
        minutes=$(printf "%.0f" $(echo "($duration % 3600) / 60" | bc))
        seconds=$(printf "%.0f" $(echo "$duration % 60" | bc))

        # Format the duration
        formatted_duration=$(printf "%02d:%02d:%02d" "$hours" "$minutes" "$seconds")
        echo "${formatted_duration}"
    else
        echo "N/A"
    fi
}

# Function to get video size in GB
get_video_size() {
    size_bytes=$(ffprobe -v error -show_entries format=size -of default=noprint_wrappers=1:nokey=1 "$1" 2>/dev/null)
    if [ "$size_bytes" != "N/A" ]; then
        size_gb=$(awk "BEGIN {printf \"%.2f\", $size_bytes / (1024^3)}")
        echo "${size_gb:-N/A} GB"
    else
        echo "N/A"
    fi
}

# Check if ffmpeg and ImageMagick are installed
if ! command -v ffmpeg &> /dev/null || ! command -v montage &> /dev/null || ! command -v convert &> /dev/null; then
    echo "Please make sure ffmpeg, ImageMagick, and montagem are installed."
    exit 1
fi

# Input video files
video1="$1"
video2="$2"

# Check if both video files are provided
if [ -z "$video1" ] || [ -z "$video2" ]; then
    echo "Usage: $0 <video1> <video2>"
    exit 1
fi

# rm -rf comparison

# Extract titles from video filenames
title1=$(basename "$video1" | sed 's/\.[^.]*$//')  # Remove extension
title2=$(basename "$video2" | sed 's/\.[^.]*$//')  # Remove extension

# Function to extract video width
get_video_width() {
    ffprobe -v error -select_streams v:0 -show_entries stream=width -of csv=s=x:p=0 "$1"
}

# Get video widths
width1=$(get_video_width "$video1")
width2=$(get_video_width "$video2")

# Determine the minimum width
min_width=$(echo "$width1 $width2" | tr ' ' '\n' | sort -n | head -n1)

# Create directories to store screenshots
mkdir -p tmp
mkdir -p tmp/screenshots1
mkdir -p tmp/screenshots2

# Extract screenshots from video1
ffmpeg -i "$video1" -vf fps=1/500 -t 1800 tmp/screenshots1/screenshot_%03d.png -hide_banner

# Extract screenshots from video2
ffmpeg -i "$video2" -vf fps=1/500 -t 1800 tmp/screenshots2/screenshot_%03d.png -hide_banner

# Check if both videos have the same number of screenshots
num_screenshots_video1=$(ls -1 tmp/screenshots1/*.png | wc -l)
num_screenshots_video2=$(ls -1 tmp/screenshots2/*.png | wc -l)
if [ "$num_screenshots_video1" -ne "$num_screenshots_video2" ]; then
    echo "Number of screenshots extracted from each video are not equal."
    exit 1
fi

# Create directory to store comparison images
mkdir -p tmp/comparison
mkdir -p comparison

# Combine screenshots for comparison and add titles
for screenshot1 in tmp/screenshots1/*.png; do
    screenshot2="tmp/screenshots2/$(basename "$screenshot1")"
    tmp_output="tmp/comparison/$(basename "$screenshot1" .png)"
    output="comparison/$(basename "$screenshot1" .png)"

    # Get video duration and size
    duration1=$(get_video_duration "$video1")
    size1=$(get_video_size "$video1")
    duration2=$(get_video_duration "$video2")
    size2=$(get_video_size "$video2")
    
    # Generate titles
    title1_image="tmp/title1.png"
    title2_image="tmp/title2.png"
    title1_with_info="$title1   |   Duration: $duration1, Size: $size1 bytes"
    title2_with_info="$title2   |   Duration: $duration2, Size: $size2 bytes"
    convert -size "${min_width}x30" -background none -fill white -gravity west -font Arial -pointsize 24 \
    caption:"$title1_with_info" "$title1_image"
    convert -size "${min_width}x30" -background none -fill white -gravity west -font Arial -pointsize 24 \
    caption:"$title2_with_info" "$title2_image"

    # Trim black bars from left and right
    convert "$screenshot1" -bordercolor black -border 1x1 -fuzz 5% -trim +repage "$screenshot1"
    convert "$screenshot1" -bordercolor black -border 1x1 -fuzz 5% -trim +repage "$screenshot2"

    # Combine screenshots and titles
    montage "$screenshot1" "$screenshot2" "$title1_image" "$title2_image" \
    -tile 2x2 -geometry +0+0 -border 5x10 -bordercolor black "${output}_labeled.png"

    montage "$screenshot1" "$screenshot2" \
    -tile 2x -geometry +0+0 -border 5x10 -bordercolor black "${tmp_output}_clean.png"
    
    # Remove temporary title images
    # rm "$title1_image" "$title2_image"
done

echo "Comparison images created in 'comparison' directory."

# Create the output filename
output_filename="comparison_result.png"
output_titles="tmp/comparison_titles.png"

# Stitch all comparison images vertically and add filename label at the top
montage tmp/comparison/*_clean.png -tile 1x -geometry +0+0 -border 0x10 -bordercolor black "$output_filename"
montage "$title1_image" "$title2_image" -tile 2x -geometry +0+0 -border 5x10 -bordercolor black "$output_titles"
montage "$output_titles" "$output_filename" -tile 1x -geometry +0+0 -border 0 -bordercolor black "$output_filename"

echo "Final comparison image created: $output_filename"

# Clean up temporary files
cleanup

video_thumbnail_comparison_2.sh

#!/bin/bash

# Function to cleanup temporary files
cleanup() {
    echo "cleaning up"
    rm -rf tmp
}

# Function to get video duration
get_video_duration() {
    duration=$(ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 "$1" 2>/dev/null)
    if [ "$duration" != "N/A" ]; then
        # Calculate hours, minutes, and seconds
        hours=$(printf "%.0f" $(echo "$duration / 3600" | bc))
        minutes=$(printf "%.0f" $(echo "($duration % 3600) / 60" | bc))
        seconds=$(printf "%.0f" $(echo "$duration % 60" | bc))

        # Format the duration
        formatted_duration=$(printf "%02d:%02d:%02d" "$hours" "$minutes" "$seconds")
        echo "${formatted_duration}"
    else
        echo "N/A"
    fi
}

split_video_timestamps() {
    # Get video duration in seconds
    # duration=$(ffmpeg -i "$1" 2>&1 | grep "Duration" | cut -d ' ' -f 4 | sed 's/,//')
    # echo $duration

    # Get video duration in seconds
    duration_seconds=$(ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 "$1" | awk '{print int($1)}')
    # echo $duration_seconds

    offset=$((duration_seconds / 8))
    echo $offset
    echo $(($offset * 3))
    echo $(($offset * 5))
    echo $(($offset * 7))
}

# Function to get video size in GB
get_video_size() {
    size_bytes=$(ffprobe -v error -show_entries format=size -of default=noprint_wrappers=1:nokey=1 "$1" 2>/dev/null)
    if [ "$size_bytes" != "N/A" ]; then
        size_gb=$(awk "BEGIN {printf \"%.2f\", $size_bytes / (1024^3)}")
        echo "${size_gb:-N/A} GB"
    else
        echo "N/A"
    fi
}

# Check if ffmpeg and ImageMagick are installed
if ! command -v ffmpeg &> /dev/null || ! command -v montage &> /dev/null || ! command -v convert &> /dev/null; then
    echo "Please make sure ffmpeg, ImageMagick, and montagem are installed."
    exit 1
fi

# Input video files
video1="$1"
video2="$2"

# Check if both video files are provided
if [ -z "$video1" ] || [ -z "$video2" ]; then
    echo "Usage: $0 <video1> <video2>"
    exit 1
fi

# rm -rf comparison

# Extract titles from video filenames
title1=$(basename "$video1" | sed 's/\.[^.]*$//')  # Remove extension
title2=$(basename "$video2" | sed 's/\.[^.]*$//')  # Remove extension

# Function to extract video width
get_video_width() {
    ffprobe -v error -select_streams v:0 -show_entries stream=width -of csv=s=x:p=0 "$1"
}

# Get video widths
width1=$(get_video_width "$video1")
width2=$(get_video_width "$video2")

# Determine the minimum width
min_width=$(echo "$width1 $width2" | tr ' ' '\n' | sort -n | head -n1)

# Create directories to store screenshots
mkdir -p tmp
mkdir -p tmp/screenshots1
mkdir -p tmp/screenshots2

i=1
timestamps_array=($(split_video_timestamps "$1"))
for timestamp in "${timestamps_array[@]}"; do
    # Extract screenshots from video1
    ffmpeg -y -ss $timestamp -i "$video1" -sn -vframes 1 tmp/screenshots1/screenshot_$(printf "%03d" "$i").png >/dev/null 2>&1

    # Extract screenshots from video2
    ffmpeg -y -ss $timestamp -i "$video2" -sn -vframes 1 tmp/screenshots2/screenshot_$(printf "%03d" "$i").png >/dev/null 2>&1

    ((i++))
done

break

# Check if both videos have the same number of screenshots
num_screenshots_video1=$(ls -1 tmp/screenshots1/*.png | wc -l)
num_screenshots_video2=$(ls -1 tmp/screenshots2/*.png | wc -l)
if [ "$num_screenshots_video1" -ne "$num_screenshots_video2" ]; then
    echo "Number of screenshots extracted from each video are not equal."
    exit 1
fi

# Create directory to store comparison images
mkdir -p tmp/comparison
mkdir -p comparison

# Combine screenshots for comparison and add titles
for screenshot1 in tmp/screenshots1/*.png; do
    screenshot2="tmp/screenshots2/$(basename "$screenshot1")"
    tmp_output="tmp/comparison/$(basename "$screenshot1" .png)"
    output="comparison/$(basename "$screenshot1" .png)"

    # Get video duration and size
    duration1=$(get_video_duration "$video1")
    size1=$(get_video_size "$video1")
    duration2=$(get_video_duration "$video2")
    size2=$(get_video_size "$video2")
    
    # Generate titles
    title1_image="tmp/title1.png"
    title2_image="tmp/title2.png"
    title1_with_info="$title1   |   Duration: $duration1, Size: $size1 bytes"
    title2_with_info="$title2   |   Duration: $duration2, Size: $size2 bytes"
    convert -size "${min_width}x30" -background none -fill white -gravity west -font Arial -pointsize 24 \
    caption:"$title1_with_info" "$title1_image"
    convert -size "${min_width}x30" -background none -fill white -gravity west -font Arial -pointsize 24 \
    caption:"$title2_with_info" "$title2_image"

    # Trim black bars from left and right
    convert "$screenshot1" -bordercolor black -border 1x1 -fuzz 5% -trim +repage "$screenshot1"
    convert "$screenshot1" -bordercolor black -border 1x1 -fuzz 5% -trim +repage "$screenshot2"

    # Combine screenshots and titles
    montage "$screenshot1" "$screenshot2" "$title1_image" "$title2_image" \
    -tile 2x2 -geometry +0+0 -border 5x10 -bordercolor black "${output}_labeled.png"

    montage "$screenshot1" "$screenshot2" \
    -tile 2x -geometry +0+0 -border 5x10 -bordercolor black "${tmp_output}_clean.png"
    
    # Remove temporary title images
    # rm "$title1_image" "$title2_image"
done

echo "Comparison images created in 'comparison' directory."

# Create the output filename
output_filename="comparison_result.png"
output_titles="tmp/comparison_titles.png"

# Stitch all comparison images vertically and add filename label at the top
montage tmp/comparison/*_clean.png -tile 1x -geometry +0+0 -border 0x10 -bordercolor black "$output_filename"
montage "$title1_image" "$title2_image" -tile 2x -geometry +0+0 -border 5x10 -bordercolor black "$output_titles"
montage "$output_titles" "$output_filename" -tile 1x -geometry +0+0 -border 0 -bordercolor black "$output_filename"

echo "Final comparison image created: $output_filename"

# Clean up temporary files
cleanup