Chiptune – A Modern C++ Real-Time Chiptune Synthesizer

A real-time software-based audio synthesis engine written in C++.
Designed to emulate the sonic character of retro hardware such as the NES, Game Boy, and Sega Genesis, while also supporting generic 8-bit waveform modes (Classic, Square, Smooth).
The engine focuses on performance, low-level DSP accuracy, and portability.

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Abstract

This project is a C++ chiptune synthesis engine that generates audio in real time using mathematical waveform generation.
It supports both hardware-inspired profiles (NES, Game Boy, Genesis) and generic modes like Square and Smooth.
The engine is built with a modular architecture powered by CMake, ensuring efficient performance and portability across platforms.

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Introduction

Chiptune music originates from the real-time waveform generators of vintage consoles and computers.
Unlike sampled audio, chiptune relies on mathematically generated waveforms, filters, and modulation techniques.

This project implements:

• Multi-style synthesis (NES, Game Boy, Sega Genesis, Square, Classic, Smooth)
• Waveform generation from DSP math
• Low-latency playback via audio callbacks
• A lightweight and portable architecture, written in modern C++

The entire system avoids heavy game engines to stay close to the hardware for accuracy and speed.

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Core Modules

Main Loop & Style Parser

Handles:

• Application initialization
• Parsing user input (e.g. genesis)
• Mapping to an internal ChiptuneStyle enum
• Selecting correct synthesis algorithms

Supported style keywords:

classic, nintendo, gameboy, genesis, square, smooth

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Waveform Generator

Core DSP engine responsible for:

• Generating Square, Triangle, Saw, and Noise waves
• Emulating hardware behaviors like:
  • NES duty cycles (Ricoh 2A03-like behavior)
  • Game Boy stereo channel quirks
  • Genesis FM-inspired harmonics

Also includes pure waveform modes (Square, Smooth) that produce mathematically clean output.

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Audio Callback

Provides real-time playback by:

• Responding to audio hardware requests
• Filling buffers with synthesized samples
• Ensuring glitchless, low-latency output
• Mixing channels and applying envelopes

This is the heartbeat of the entire engine.

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Build Instructions

Requirements

• C++ compiler (C++11 or later)
• CMake
• Platform-specific audio backend

Build

git clone https://github.com/Ravish-Ranjan/chiptune
cd chiptune
mkdir build && cd build
cmake ..
make

Run:

./chiptune <audio-file-path> <style?>

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Supported Synthesis Styles

Style	Mode	Description
classic	CLASSIC	Arcade-style 8-bit tone
nintendo	NINTENDO	NES pulse waves + duty cycles
gameboy	GAMEBOY	Stereo wave-channel emulation
genesis	GENESIS	FM-inspired Sega Genesis tone
square	SQUARE	Pure, raw square wave
smooth	SMOOTH	Filtered, cleaner chiptune output

Default output mode: smooth

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Result

Running the application produces real-time synthesized chiptune audio.
The selected style determines oscillator behavior, mixing rules, and overall timbre, giving users full control over retro sound emulation.

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References

• CMake Documentation – https://cmake.org/documentation/

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