WebM to MP4 Video Converter

A Python script that converts all WebM video files in a folder to MP4 format at the highest possible resolution.

Features

• 🎥 Converts WebM files to MP4 at highest quality (visually lossless)
• 📁 Automatically creates an mp4 subfolder for output files
• 🔧 Preserves original video resolution and quality
• 💾 Option to keep or delete original files
• 🖥️ Windows CMD/PowerShell compatible
• 📊 Shows conversion progress and summary

Requirements

1. Python 3.6+

Download and install Python from python.org

2. FFmpeg

FFmpeg is required for video conversion. Choose one installation method:

Option A: Using winget (Windows 10/11)

winget install ffmpeg

Option B: Manual installation

1. Download FFmpeg from ffmpeg.org/download.html
2. Extract the files to a folder (e.g., C:\ffmpeg)
3. Add the bin folder to your system PATH environment variable

Option C: Using Chocolatey

choco install ffmpeg

Installation

1. Download all files to a folder
2. No additional Python packages required (uses standard library)

Usage

Method 1: Double-click the batch file (Easiest)

1. Double-click convert_videos.bat
2. Enter the folder path containing WebM files when prompted
3. Wait for conversion to complete

Method 2: Command line with folder path

python video_converter.py "C:\Path\To\Your\WebM\Files"

Method 3: Interactive mode

python video_converter.py

Then enter the folder path when prompted.

Method 4: Keep original files

python video_converter.py "C:\Path\To\Your\WebM\Files" --keep-original

How it works

1. Input: You provide a folder path containing WebM files
2. Processing: The script finds all .webm files in the folder
3. Output: Creates a new mp4 subfolder and saves converted files there
4. Cleanup: Optionally deletes original WebM files (default behavior)

Example

Your folder structure:
C:\Videos\
├── video1.webm
├── video2.webm
└── video3.webm

After conversion:
C:\Videos\
├── mp4\
│   ├── video1.mp4
│   ├── video2.mp4
│   └── video3.mp4

Conversion Settings

The script uses these FFmpeg settings for highest quality:

• Video codec: H.264 (libx264)
• Quality: CRF 18 (visually lossless)
• Preset: Slow (better compression)
• Audio codec: AAC at 192k bitrate
• Optimization: Fast start for streaming

Troubleshooting

"ffmpeg is not installed or not found in PATH"

• Install FFmpeg using one of the methods above
• Restart your command prompt/PowerShell after installation
• Make sure FFmpeg is in your system PATH

"No WebM files found"

• Check that the folder path is correct
• Ensure files have .webm extension (case insensitive)
• Make sure you have read permissions for the folder

Conversion fails

• Check that you have write permissions in the target folder
• Ensure there's enough disk space
• Try with a different WebM file to isolate the issue

Creating an Executable (Optional)

To create a standalone .exe file:

1. Install PyInstaller:

pip install pyinstaller

2. Create the executable:

pyinstaller --onefile --console video_converter.py

3. The .exe file will be in the dist folder

License

This project is free to use and modify.

Support

If you encounter issues:

1. Check that Python and FFmpeg are properly installed
2. Verify the folder path is correct
3. Ensure you have proper file permissions
4. Try running the script with a single test file first