Video Optimizer - Lossless Compression Web App

Tech Stack

Additional Technologies

• H.264 Codec - Video compression standard
• AAC Audio - Audio compression
• UUID - Unique file identification
• Threading - Background processing
• Subprocess - FFmpeg integration

A modern web application for optimizing video files with lossless compression. Perfect for reducing file sizes while maintaining visual quality.

Features

• 🎬 Drag & Drop Upload: Easy file upload with drag-and-drop interface
• 🔄 Real-time Progress: Live progress tracking during optimization
• 📊 File Size Comparison: Shows original vs optimized file sizes
• 🎯 Lossless Compression: Uses H.264 with CRF 18 for visually lossless quality
• 📱 Responsive Design: Works on desktop and mobile devices
• 🗂️ Multiple Formats: Supports MP4, AVI, MOV, MKV, WMV, FLV, WebM, M4V
• ⚡ Background Processing: Non-blocking video optimization
• 🧹 Auto Cleanup: Automatically removes old files

Installation

Prerequisites

1. Python 3.7+ installed on your system
2. FFmpeg installed and available in your PATH

Install FFmpeg

Ubuntu/Debian:

sudo apt update
sudo apt install ffmpeg

macOS (using Homebrew):

brew install ffmpeg

Windows:

Download from FFmpeg official website or use Chocolatey:

choco install ffmpeg

Install Python Dependencies

1. Clone or download this repository
2. Navigate to the project directory
3. Install Python dependencies:

pip install -r requirements.txt

Usage

Starting the Application

1. Run the Flask application:

python app.py

2. Open your web browser and go to:

http://localhost:5000

Using the Application

1. Upload Video: Drag and drop your video file onto the upload area or click to browse
2. Monitor Progress: Watch the real-time progress bar and status updates
3. Download Result: Once optimization is complete, click the download button to get your optimized video

Optimization Settings

The application uses the following FFmpeg settings for optimal compression:

• Video Codec: H.264 (libx264)
• Preset: veryslow (best compression)
• CRF: 18 (visually lossless quality)
• Audio Codec: AAC
• Audio Bitrate: 128k
• Web Optimization: Fast start enabled

File Structure

optimiser/
├── app.py              # Main Flask application
├── requirements.txt    # Python dependencies
├── README.md          # This file
├── templates/
│   └── index.html     # Web interface
├── uploads/           # Temporary upload directory
└── output/            # Optimized video output directory

Technical Details

Compression Algorithm

The application uses FFmpeg with the following optimization strategy:

1. H.264 Codec: Industry standard for video compression
2. CRF 18: Constant Rate Factor ensures visually lossless quality
3. Veryslow Preset: Maximizes compression efficiency
4. AAC Audio: Efficient audio compression
5. Fast Start: Optimizes for web streaming

Performance

• Processing Speed: Depends on video length and system performance
• Compression Ratio: Typically 20-60% size reduction
• Quality: Visually lossless (CRF 18)
• Memory Usage: Minimal, processes files in chunks

Supported Video Formats

• MP4 (recommended)
• AVI
• MOV
• MKV
• WMV
• FLV
• WebM
• M4V

Troubleshooting

Common Issues

1. FFmpeg not found: Ensure FFmpeg is installed and in your system PATH
2. Large file uploads: The application handles large files, but upload time depends on your internet connection
3. Processing errors: Check that your video file is not corrupted and is in a supported format

Error Messages

• "No file selected": Make sure you've selected a video file
• "Invalid file type": Ensure your file is in a supported format
• "Optimization failed": Check your video file for corruption

Development

Running in Development Mode

python app.py

The application runs on http://localhost:5000 with debug mode enabled.

Customizing Optimization Settings

You can modify the FFmpeg parameters in the optimize_video function in app.py:

cmd = [
    'ffmpeg', '-i', input_path,
    '-c:v', 'libx264',           # Video codec
    '-preset', 'veryslow',        # Compression preset
    '-crf', '18',                 # Quality setting (lower = better quality)
    '-c:a', 'aac',                # Audio codec
    '-b:a', '128k',               # Audio bitrate
    '-movflags', '+faststart',    # Web optimization
    '-y',                         # Overwrite output
    output_path
]

License

This project is open source and available under the MIT License.

Contributing

Feel free to submit issues, feature requests, or pull requests to improve this application.