Mp4Forge

A modern MP4 muxing tool with a desktop GUI interface, powered by MP4Box.

Desktop Application

WebUI (Docker/headless)

Features

• Multi-track support: Add multiple video, audio, subtitle, and chapter tracks to a single MP4 container
• Multi-track MP4 audio selection: Select specific audio tracks from MP4 files containing multiple audio streams
• Language & metadata: Set language codes, titles, default/forced flags for all tracks
• Audio delay: Support for audio delay values (automatically detected from filenames or MediaInfo)
• Chapter support: Import chapters from OGM/XML files or other MP4 containers
• Queue system: Build and manage multiple muxing jobs in a queue
• Cross-platform: Available for Windows (8+ x64), macOS, and Linux
• Theme support: Light, dark, and auto themes
• Quick access titles: Save and use quick access titles for audio/subtitles

Supported Formats

Video: H.264/AVC, H.265/HEVC, MP4/M4V
Audio: AAC, AC3, E-AC3, MP2, MP3, Opus, OGG, MP4/M4A (with multi-track selection)
Subtitles: SRT, SSA, ASS, VTT, MP4/M4V
Chapters: OGM, XML, MP4 (extracted from existing files)
Output: MP4 container only

Desktop Application Requirements

MP4Box must be installed and available in your system PATH, or configured in the application settings.

• Download MP4Box: GPAC Downloads
• Or install via package manager:
  • Windows: winget install GPAC.GPAC or choco install gpac
  • macOS: brew install gpac
  • Linux: apt install gpac or yum install gpac

Docker Application Requirements

Everything is self contained and included that you would need.

Installation

Option 1: Download Pre-built Binaries (Recommended)

1. Go to the Releases page
2. Download the archive for your platform:
   • Windows: Mp4Forge-Windows.zip
   • macOS (Apple Silicon): Mp4Forge-macOS-ARM64.zip
   • macOS (Intel): Mp4Forge-macOS-Intel.zip
   • Linux: Mp4Forge-Linux.tar.gz
3. Extract the archive
4. Run the application:
   • Windows: Run Mp4Forge.exe
   • macOS: Extract the .zip and drag Mp4Forge.app to your Applications folder, then launch from Launchpad or Finder
   • Linux: Run ./Mp4Forge

Option 2: Run from Source

Requirements: Python 3.11 or 3.12, uv

git clone https://github.com/jessielw/MP4-Mux-Tool.git
cd MP4-Mux-Tool
uv sync --all-extras
uv run python frontend_desktop/main.py

Option 3: Docker (Web Interface)

Run MP4Forge with a web interface using Docker:

Compose Example:

services:
  mp4forge:
    image: ghcr.io/jessielw/mp4forge:latest
    platform: linux/amd64
    container_name: mp4forge-web
    ports:
      - "8000:8000"
    volumes:
      # mount for persistent config and logs
      - /SOME_PATH/runtime:/app/runtime
      # mount volume(s) you may need for input/output files
      - /SOME_PATH:/data/SOME_PATH
      - /SOME_PATH2:/data/SOME_PATH2
    environment:
      - PYTHONUNBUFFERED=1
    restart: "no"
    healthcheck:
      test: ["CMD", "curl", "-f", "http://localhost:8000/api/health"]
      interval: 60s
      timeout: 10s
      retries: 3
      start_period: 10s

Usage

1. Add tracks: Use the Video, Audio, Subtitles, and Chapters tabs to add input files

   • Drag & drop files directly onto input fields (desktop only)
   • Use the file browser button
   • For multi-track MP4 audio files, a track selector dialog will appear

2. Configure metadata: Set language, title, default/forced flags, and delay for each track

3. Set output: Go to the Output tab and specify your output file path

4. Add to queue: Click "Add Current Job" to add the muxing job to the queue

5. Process: Click "Process Queue" to start muxing all queued jobs

Multi-track Audio

When adding an MP4 file with multiple audio tracks to an audio tab, Mp4Forge will display a track selector dialog showing:

• Track ID
• Format
• Channels
• Bitrate
• Sample rate
• Language
• Title
• Delay

Select the track you want to use and click OK.

Portable Mode

By default, configuration is stored in your OS user config directory:

• Windows: %APPDATA%\Mp4Forge\config.toml
• macOS: ~/Library/Application Support/Mp4Forge/config.toml
• Linux: ~/.config/Mp4Forge/config.toml

For portable installations, the config is stored in the runtime/ folder alongside the executable (desktop only).

Development

Building from Source

# Install dependencies
uv sync --all-extras

# Run the application
uv run python frontend_desktop/main.py

# Build executables
uv run python build_desktop.py

Tech Stack

Desktop

• Backend: MP4Box (GPAC)
• Frontend: PySide6 (Qt6)
• Build: PyInstaller
• Package Manager: uv
• MediaInfo: pymediainfo for track inspection

WebUI

• Backend: Python/FastAPI/GPAC
• Frontend: Svelte
• Build: Docker
• Package Managers: uv & node
• MediaInfo: pymediainfo for track inspection

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.

License

See LICENSE for details.

Credits

• Powered by GPAC/MP4Box
• Built with PySide6