FonkPlay 🎵

A web-based MOD/S3M tracker module player with DOS-era CRT aesthetics and modern audio features.

Features

• MOD & S3M support - Play classic tracker modules from the Amiga and PC demoscene era
• 32-channel playback - Full support for multi-channel S3M files
• Real-time waveform display - Oscilloscope visualization for each channel
• Three interpolation modes:
  • Sound Blaster (none) - Authentic crunchy 90s sound
  • Gravis Ultrasound (linear) - Smooth classic sound
  • Modern (8-point sinc) - High-quality interpolation
• Surround sound modes:
  • Stereo - Standard output
  • Pro Logic Surround - Dolby Pro Logic matrix encoding for home theater
  • Headphone HRTF - Binaural 3D audio with proper HRTF convolution
• Automatic sample classification - AI-powered detection of bass, drums, leads, pads for surround placement
• WAV export - Render modules to WAV with selectable quality
• Timeline scrubbing - Jump to any position in the song
• Channel solo - Click any channel to solo it

Technical Highlights

• AudioWorklet with ScriptProcessorNode fallback
• S-curve (smoothstep) volume ramping for click-free transitions
• Sample-rate vibrato with integrated sine anti-aliasing
• 64-tap HRTF convolution based on KEMAR measurements
• 21-tap Hilbert transform for Pro Logic surround encoding
• Zero dependencies - Single HTML file, no build step

Usage

1. Open FonkPlay
2. Drag & drop a .mod or .s3m file (or click to browse)
3. Enjoy!

Tips

• Click channel - Solo (click again to unsolo)
• Drag timeline - Scrub to any position

About the Surround Modes

Pro Logic Surround

Uses Hilbert transform to create 90° phase-shifted surround channel, compatible with any Dolby Pro Logic decoder. Bass stays center, leads up front, pads and textures in the rear.

Headphone HRTF

Proper binaural processing using 64-tap head-related impulse responses. Creates convincing "behind you" perception for surround content through regular headphones.

Sample Classification

Each sample is automatically analyzed using:

• Audio analysis: Zero-crossing rate, attack time, sustain level, noise content
• Pattern analysis: Beat alignment, note variety, trigger frequency

This determines optimal surround placement:

Type	Detection	Placement
Bass	Low frequency	Center
Drums	Fast attack + beat-aligned	Front
Lead	Melodic content	Front
Pad	Slow attack + sustained	Rear
Texture	Noisy + looped	Surround

License

MIT License - See LICENSE file

Credits

• Psyke/DCB & VIP/DCB - Original ASM player code
• Built with ❤️ and Claude