Node-Based Audio Editor

Audio_Editor

Introduction

Audio_Editor is a node-based audio editing tool developed in C++ during my third year at Gaming Campus (GTech, Tech – Engine specialization) under the supervision of Johann Philippe.

The goal of this project was to build a fully functional WAV audio editor, capable of:

  • Loading audio files
  • Editing them with various transformations
  • Playing them in real time
  • Saving the modified result

Beyond the tool itself, this project was a deep dive into:

  • Digital signal processing fundamentals
  • Audio data representation
  • Low-level audio playback systems

We chose to focus on creating a user-friendly and visual workflow, inspired by node-based editors commonly used in game engines and creative software.

Project Context & Objectives

The project required us to:

  • Work with raw WAV file formats
  • Understand how audio data is stored and processed
  • Implement editing features from scratch
  • Use a low-level API (XAudio) to handle sound playback

Key objectives included:

  • Building a fully interactive editor
  • Providing visual feedback of the audio signal
  • Allowing non-destructive-style manipulation workflows
  • Keeping the tool intuitive despite technical complexity

Node-Based Editor Interface

One of the core design choices was to build a node-based editing interface.

Instead of a traditional timeline-only editor, we implemented:

  • An infinite canvas
  • Draggable audio nodes
  • A system to organize and manipulate audio visually

Users can:

  • Create nodes representing audio clips
  • Move them freely in space
  • Select and edit them independently

This approach:

  • Makes the editor more modular and flexible
  • Encourages experimentation
  • Aligns with workflows used in modern tools (e.g. shader graphs, visual scripting)

Node Canvas

Audio Visualization

A key feature of the editor is the accurate waveform visualization.

We implemented a system that:

  • Reads raw audio sample data from WAV files
  • Converts it into a visual waveform representation
  • Displays it in real time inside the editor

This allowed users to:

  • Precisely see the structure of the sound
  • Make accurate selections and edits
  • Better understand how transformations affect the signal

Waveform

Editing Features

The editor includes a variety of audio manipulation tools, all implemented from scratch:

Basic Editing

  • Selection of audio segments
  • Cut / Copy / Paste
  • Reverse audio
  • Amplitude (intensity) adjustment

Effects

We also implemented several classic audio effects:

  • Fade In / Fade Out
  • Echo / Reverb (simple implementations)

These effects required directly manipulating the sample data, reinforcing our understanding of:

  • Signal transformations
  • Time-based audio effects
  • Buffer processing

Editing

Frequency Analysis (FFT)

To go further, we implemented a frequency domain analysis using FFT (Fast Fourier Transform).

This allowed us to:

  • Extract frequency information from the signal
  • Visualize it as a spectrum representation

This feature provided:

  • A different perspective on sound (frequency vs time domain)
  • A more technical and analytical tool within the editor

FFT

Multi-Channel Support

The editor supports multi-channel audio and allows:

  • Viewing each channel independently
  • Better understanding of stereo and spatial audio

This was important to:

  • Correctly interpret WAV file structures
  • Ensure accurate playback and editing

Channels

Audio Playback with XAudio

For real-time playback, we used XAudio, a low-level audio API.

This required:

  • Managing audio buffers manually
  • Sending processed data directly to the sound card
  • Handling playback states and synchronization

Working with XAudio gave us insight into:

  • How audio is actually streamed to hardware
  • The importance of performance and memory management
  • Low-level systems programming in a real-world context

Technical Challenges

Understanding Raw Audio Data

One of the biggest challenges was learning how to:

  • Interpret binary WAV file structures
  • Convert raw data into usable sample buffers
  • Handle different formats and edge cases

Real-Time Processing

Applying effects while maintaining:

  • Performance
  • Responsiveness
  • Accuracy

…was a non-trivial task, especially in C++ without high-level libraries.

UX vs Technical Complexity

We aimed to keep the editor:

  • Accessible
  • Visual
  • Easy to use

…while dealing with inherently complex systems like:

  • Signal processing
  • Memory management
  • Real-time playback

Balancing both aspects was a key challenge of the project.

Conclusion

Audio_Editor was a highly technical and rewarding project that expanded my understanding of audio programming at a low level.

Through this project, I learned:

  • How sound is represented digitally
  • How to implement audio processing algorithms
  • How to use a low-level API (XAudio) for playback
  • How to design a tool-oriented application with a strong UX focus

Building a complete audio editor from scratch gave me valuable experience in both:

  • engine-level programming
  • and user-facing tool design

It also strengthened my ability to bridge the gap between complex technical systems and intuitive user experiences.