projet μ is a free online textbook about the basics of audio DSP and audio programming in low-level C.

Each unit is practical and goal-oriented: we build a small audio toy from scratch, learn the necessary theory and techniques, but keep the math and implementations explicit to build a low-level intuition. The goal isn't to cover everything, but to build a good fundation to explore deeper topics independently.

The online textbook isn't directly talking about JUCE, but it will help you understand how JUCE works in low level. We will use a Linux environment (or macOS, BSDs, MSYS/MinGW on Windows) and the JACK Audio Connection Kit to write the examples in C, but they can be easily translated to any framework and any programming language.

Prerequisites:

1. C programming and familiarity with UNIX shell utilities
2. Integral calculus
3. Geometric understanding of complex numbers (you need to know what e^iθ means geometrically)

Topics covered:

• wave: WAV audio format, basic DSP theory
• wave♯: WAV file loading, AMDF pitch estimation
• osc (part i): oscillators, phasors, JACK Audio Connection Kit, joystick interface
• osc (part ii): Fourier series, aliasing, wavetable synthesis, bandlimited oscillators
• osc♯: 2D wavetable, wave terrain synthesis
• mix: Open Sound Control (OSC), parameter smoothing, the decibel (dB) scale.
• adsr: ADSR envelope generators
• ctrl: thread safety, inter-thread communication, ring buffers.
• delay: delay/echo effects, basic FIR and IIR filters
• delay♯: Karplus-Strong algorithm, simple digital waveguide synthesis
• dft: Discrete Fourier Transform (DFT/FFT), connection between discrete-time and continuous-time Fourier transforms, the Fourier cube
• spectrm: audio spectrum visualization, framebuffer rendering, DFT of real signals, the FFTW library
• spectrm♯: DFT spectral leakage, windowing, zero-padding
• reverb: artificial reverb algorithms, convolution
• ext: dynamic linking, audio plugins (LADSPA, LV2, VST, CLAP, etc.)
• denormal: IEEE 754 denormal/subnormal numbers, floating point optimization
• ...