Tandy DigiCD Launcher

A digital music format that embeds MP3 audio data inside of PNG files.

Download the DigiCD below and play here

The DigiCD Format

DigiCDs are PNG images that contain hidden MP3 data, allowing music to be stored and shared as images.

Encoding Process

Image Preparation

• Takes source PNG image and MP3 file
• Extracts raw image data into a buffer

Data Embedding

• Converts MP3 file to binary data
• Injects MP3 data into a custom chunk
• Performs CRC32 checksum on the data
• Writes the data to a new PNG file

Decoding Process

Validation

• Checks PNG signature (‰PNG\r\n\x1A\n)
• Verifies presence of DigiCD custom chunk
• Validates CRC32 checksum

Data Extraction

• Locates embedded MP3 data using custom chunk identifier
• Creates Blob URL for audio playback

Technologies

• Frontend: Vanilla JavaScript, HTML5, CSS3
• Audio Processing: Web Audio API
• Image Processing: Canvas API
• File Handling: Blob API, FileReader API
• Metadata: jsmediatags library