mkv2mp4ui

MKV to MP4 UI

A modern, user-friendly PyQt6 GUI application for batch converting MKV video files to MP4 format using FFmpeg. Perfect for converting movie collections ripped with MakeMKV or HandBrake into a more universally compatible format.

Features

🎬 Batch Conversion - Select and convert multiple MKV files at once
⚡ Real-time Progress - Live FFmpeg output with encoding speed and ETA
🔧 Configurable Settings - Choose video/audio codecs, quality, and presets
📁 Flexible Output - Convert to source folder or choose custom output directory
🖥️ Cross-platform - Works on Windows, macOS, and Linux
📦 Self-contained - Automatic FFmpeg download and installation
🎯 User-friendly - Modern GUI with progress tracking and detailed logs

Installation

From PyPI (Recommended)

pip install mkv2mp4ui

From Source

git clone https://github.com/scottpeterman/mkvtomp4ui.git
cd mkvtomp4ui
pip install -r requirements.txt
python -m mkv2mp4ui.main

Usage

Launch the Application

After installation, you can start the application in several ways:

# Command line
mkv2mp4ui

# Or as a GUI application
mkv2mp4ui-gui

# Or from Python
python -m mkv2mp4ui.main

Using the GUI

1. Select Source Folder

• Click "Select Folder with MKV Files"
• Browse to the directory containing your MKV files
• The application will automatically scan for all .mkv files in the folder and subfolders

2. Choose Output Location (Optional)

• By default, MP4 files are saved in the same location as the source MKV files
• Click "Select Output Folder" to choose a different destination
• Useful for organizing converted files separately

3. Configure Conversion Settings

Video Codec:

• libx264 - Widely compatible H.264 encoding (recommended)
• libx265 - More efficient H.265/HEVC encoding (smaller files)
• copy - Copy video stream without re-encoding (fastest, preserves quality)

Audio Codec:

• aac - Standard AAC audio (recommended for compatibility)
• mp3 - MP3 audio encoding
• copy - Copy audio stream without re-encoding

Quality (CRF):

• Range: 0-51 (lower = better quality, larger files)
• Recommended: 18-28
• Default: 23 (good balance of quality and file size)

Preset:

• veryfast to veryslow - Controls encoding speed vs compression efficiency
• medium is the default and recommended for most users

4. Select Files for Conversion

• All discovered MKV files are listed with checkboxes
• Use "Select All" to quickly select/deselect all files
• Manually check/uncheck individual files as needed
• The status shows "X/Y files selected"

5. Start Conversion

• Click "Start Conversion" to begin the batch process
• Monitor real-time progress with:
  • Progress bar showing overall completion
  • Status display with current file, progress percentage, encoding speed, and ETA
  • Detailed log showing live FFmpeg output with color-coded messages
• Use "Stop Conversion" to cancel the process if needed

6. Monitor Progress

The application provides comprehensive feedback:

• Blue text: FFmpeg progress information (frame rate, speed, bitrate)
• Orange text: Warnings or non-critical issues
• Red text: Errors or failures
• Progress percentage: How much of the current file has been processed
• Encoding speed: How fast the conversion is running (e.g., "13.5x" = 13.5 times real-time)
• ETA: Estimated time of completion

7. Completion

• A dialog will notify you when all conversions are complete
• Check the log for any errors or warnings
• Converted MP4 files will be in your specified output location

FFmpeg Installation

The application includes an automatic FFmpeg downloader:

• First run: If FFmpeg is not found, a dialog will offer to download it automatically
• Manual installation: You can also download FFmpeg manually and place it in the application directory
• System installation: The app will use FFmpeg if it's already installed in your system PATH

Common Use Cases

Converting Movie Collections

Perfect for converting movies ripped with MakeMKV or HandBrake:

Source: /Movies/Lord_of_the_Rings/
├── Fellowship.mkv
├── Two_Towers.mkv
└── Return_of_the_King.mkv

Output: /Movies/Lord_of_the_Rings/
├── Fellowship.mp4
├── Two_Towers.mp4
└── Return_of_the_King.mp4

Quality vs Speed Settings

Fast conversion (copy streams):

• Video Codec: copy
• Audio Codec: copy
• Use when: MKV container is the only issue, codecs are already compatible

High quality re-encoding:

• Video Codec: libx264 or libx265
• Audio Codec: aac
• Quality (CRF): 18-20
• Preset: slow or slower

Balanced conversion:

• Video Codec: libx264
• Audio Codec: aac
• Quality (CRF): 23
• Preset: medium

System Requirements

• Python: 3.8 or higher
• Operating System: Windows, macOS, or Linux
• Memory: 4GB RAM recommended for HD video conversion
• Storage: Ensure adequate free space (MP4 files may be larger or smaller than MKV depending on settings)

Troubleshooting

FFmpeg Not Found

• Use the automatic download feature in the application
• Or manually download from FFmpeg.org
• Ensure ffmpeg.exe is in your PATH or application directory

Conversion Failures

• Check the conversion log for detailed error messages
• Verify source files are not corrupted
• Ensure sufficient disk space for output files
• Try different codec settings if specific files fail

Performance Issues

• Use "copy" codecs when possible for fastest conversion
• Choose faster presets (fast, veryfast) for quicker processing
• Close other applications to free up system resources
• Consider converting files individually if batch processing is too slow

Contributing

Contributions are welcome! Please feel free to submit pull requests, bug reports, or feature requests.

License

This project is licensed under the GPLv3 License - see the LICENSE file for details.

Acknowledgments

• Built with PyQt6 for the GUI
• Uses FFmpeg for video conversion
• Inspired by the need for a simple, user-friendly MKV to MP4 converter

Note: This application is designed for personal use with your own video files. Ensure you have the right to convert any video files you process.