BWF Marker Extractor

A web application for extracting BWF (Broadcast Wave Format) markers from WAV files which are written for example by Zoom H5 Handy Recorder and converting them to Audacity-compatible label files which can be imported using "File → Import → Labels" in Audacity.

Free to use Online Demo

Free to use online demo is available at: https://bwf.projecttac.com

Features

• Upload multiple WAV files with embedded BWF marker data
• Extract markers using the bwfmetaedit command-line tool
• Convert XML marker data to Audacity label format
• Download processed label files for import into Audacity
• Modern web interface with drag-and-drop support
• Docker containerization for easy deployment

Requirements

• Node.js 18+ (for local development)
• Docker and Docker Compose (for containerized deployment)
• bwfmetaedit tool (compiled from source in Docker image)

Installation & Usage

Using Docker (Recommended)

1. Clone this repository:

   git clone <repository-url>
   cd bwf-marker-extractor

2. Build and run with Docker Compose:

   docker-compose up --build

3. Open your browser and navigate to http://localhost:3000

Local Development

1. Install dependencies:

   npm install

2. Install bwfmetaedit on your system:

   • Ubuntu/Debian: Compile from source (see BWFMetaEdit GitHub)

     sudo apt-get install git automake autoconf libtool pkg-config make g++ zlib1g-dev
     git clone https://github.com/MediaArea/BWFMetaEdit.git
     cd BWFMetaEdit/Project/GNU/CLI
     ./autogen.sh && ./configure && make && sudo make install

   • macOS: brew install bwfmetaedit
   • Windows: Download from MediaArea website

3. Build the project:

   npm run build

4. Start the server:

   npm start

   Or for development with auto-reload:

   npm run dev

5. Open your browser and navigate to http://localhost:3000

How It Works

1. Upload: Users can upload one or more WAV files containing BWF marker data
2. Extract: The server uses bwfmetaedit to extract metadata as XML
3. Convert: The XML is parsed and converted to Audacity label format
4. Download: Users can download the generated label files

API Endpoints

• GET / - Main web interface
• POST /upload - Upload WAV files for processing
• GET /download/:filename - Download processed label files

File Formats

Input

• WAV files with embedded BWF marker data

Output

• Text files in Audacity label format:

  start_time	end_time	label
  0.000000	0.000000	Marker 1
  30.500000	30.500000	Marker 2
  

Configuration

Environment variables:

• PORT - Server port (default: 3000)
• NODE_ENV - Environment (development/production)
• MAX_FILE_SIZE_MB - Maximum file size per upload in MB (default: 100)

Development

Project Structure

├── src/
│   ├── server.ts              # Main server file
│   └── services/
│       └── marker-converter.ts # XML to label conversion logic
├── public/
│   └── index.html             # Frontend interface
├── Dockerfile                 # Docker configuration
├── docker-compose.yml         # Docker Compose setup
└── package.json               # Node.js dependencies

Building

npm run build    # Compile TypeScript
npm run watch    # Watch mode for development

Testing

Upload test WAV files with BWF markers and verify:

1. Files are processed without errors
2. Label files are generated correctly
3. Labels can be imported into Audacity

Troubleshooting

Common Issues

1. "bwfmetaedit not found"

   • Ensure bwfmetaedit is installed and in PATH
   • Use Docker image which includes the tool

2. "No markers found"

   • Verify WAV file contains BWF marker data
   • Check XML output for correct structure

3. Upload fails

   • Ensure files are valid WAV format
   • Check file size limits

Logs

Check server logs for detailed error information:

docker-compose logs -f bwf-marker-extractor

License

MIT License - see LICENSE file for details

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Test thoroughly
5. Submit a pull request