FFmpeg Alpha Compositor GUI

A simple, user-friendly graphical interface for compositing image sequences with alpha channels using FFmpeg.

Features

• Easy Folder Selection: Browse and select source and alpha image sequences with a simple GUI
• Automatic Frame Detection: Automatically detects the number of frames in both sequences
• Alpha Channel Options: Option to invert the alpha channel (white becomes transparent, black becomes opaque)
• Multiple Output Formats:
  • PNG Image Sequence (with alpha transparency)
  • ProRes 4444 Video (professional format with alpha)
  • WebM Video (web-compatible with alpha)
• Automatic Scaling: Alpha sequence automatically scales to match source dimensions
• Frame Rate Control: Set custom frame rates (default: 24 FPS)
• Real-time Progress: Visual progress bar showing processing status

Requirements

For Running from Source

• Python 3.6 or higher
• Tkinter (included with Python)
• FFmpeg executable

For Running Standalone Executable

• FFmpeg executable in the same directory as the application
• Windows 10/11 (for the .exe version)

Installation

Option 1: Run from Source

1. Ensure Python 3.6+ is installed on your system
2. Download ffmpeg_gui.py
3. Download FFmpeg from https://ffmpeg.org/download.html
4. Place ffmpeg.exe in the same directory as ffmpeg_gui.py
5. Run the application:

   python ffmpeg_gui.py

Option 2: Use Standalone Executable

1. Download the latest release ffmpeg_gui.exe
2. Download FFmpeg from https://ffmpeg.org/download.html
3. Place ffmpeg.exe in the same directory as ffmpeg_gui.exe
4. Double-click ffmpeg_gui.exe to run

Usage Guide

Step 1: Select Source Images

Click "Browse..." next to "Source Image Sequence" and select the folder containing your main image sequence.

Step 2: Select Alpha Images

Click "Browse..." next to "Alpha Image Sequence" and select the folder containing your black and white alpha/matte sequence.

Step 3: Configure Processing Options

• Invert Alpha Channel: Check this if you need to invert the alpha (useful when white areas should be transparent)
• Frame Rate: Enter the desired output frame rate (default is 24 FPS)

Step 4: Choose Output Format

Select one of the following:

• PNG Image Sequence: Creates individual PNG files with transparency
• ProRes 4444: Professional video format with alpha channel (large files, high quality)
• WebM: Web-compatible video format with alpha channel (smaller files)

Step 5: Select Output Location

• For image sequences: Select the output folder
• For video files: Choose where to save the video file

Step 6: Process

Click "Process Images" to start the compositing process. The progress bar will show the current status.

Supported Image Formats

The application supports the following image formats:

• PNG (.png)
• JPEG (.jpg, .jpeg)
• TIFF (.tif, .tiff)
• EXR (.exr)
• DPX (.dpx)

Important Notes

1. Frame Numbering: Your image sequences should have numbered frames (e.g., frame_0001.png, frame_0002.png, etc.)

2. Automatic Scaling: The alpha sequence will be automatically scaled to match the source sequence dimensions

3. Frame Count: The application will use the larger frame count between source and alpha sequences

4. FFmpeg Location: The application looks for ffmpeg.exe in its own directory first. If not found, it will try to use FFmpeg from the system PATH.

Troubleshooting

"FFmpeg Not Found" Error

• Ensure ffmpeg.exe is in the same directory as the application
• Download FFmpeg from: https://ffmpeg.org/download.html

No Images Found

• Check that your image sequences are in supported formats
• Ensure images are properly numbered sequentially

Processing Fails

• Verify both source and alpha folders contain valid image sequences
• Check that the output location is writable
• Ensure you have sufficient disk space

Memory Issues

• For very large image sequences, consider processing in smaller batches
• Close other applications to free up memory

Building from Source

If you want to build the executable yourself:

1. Install PyInstaller:

   pip install pyinstaller

2. Build the executable:

   pyinstaller --onefile --windowed --name ffmpeg_gui ffmpeg_gui.py

3. The executable will be created in the dist folder

FFmpeg Command Examples

The application generates FFmpeg commands similar to these:

PNG Sequence with Alpha:

ffmpeg -framerate 24 -i source/img_%04d.png -framerate 24 -i alpha/alpha_%04d.png \
  -filter_complex "[1:v]format=gray,scale=1920:1080[alpha];[0:v][alpha]alphamerge" \
  -c:v png -pix_fmt rgba output/comp_%04d.png

ProRes 4444 with Alpha:

ffmpeg -framerate 24 -i source/img_%04d.png -framerate 24 -i alpha/alpha_%04d.png \
  -filter_complex "[1:v]format=gray,scale=1920:1080[alpha];[0:v][alpha]alphamerge" \
  -c:v prores_ks -profile:v 4444 -pix_fmt yuva444p10le output.mov

License

This application is provided as-is for free use. FFmpeg is a separate project with its own licensing.

Support

For issues or questions, please check the troubleshooting section above or consult the FFmpeg documentation at https://ffmpeg.org/documentation.html

Version History

• v1.0.0 - Initial release with core features

  • Image sequence and video output support

  • Alpha channel inversion

  • Automatic scaling

  • Progress tracking