Tutorials

Step-by-step guides for DSP concepts using the miniDSP library. Each tutorial explains the theory, walks through a working example, and shows the resulting plots.

• Signal Generators — Generate test signals (sine waves, white noise, impulse, chirp, and more).
• Window Functions — Compare Hanning, Hamming, Blackman, and rectangular windows for FFT analysis.
• Computing the Magnitude Spectrum — Decompose a signal into its frequency components using the DFT.
• Computing the Power Spectral Density — Measure how signal power distributes across frequencies.
• Spectrogram and the STFT — Visualise how a signal's frequency content changes over time.
• Mel Filterbank and MFCCs — Build mel filterbank energies and MFCCs for speech/audio ML front-ends.
• Phase Spectrum — Inspect the per-frequency phase angle of a real signal.
• Basic Signal Operations — RMS, zero-crossing rate, autocorrelation, peak detection, and signal mixing.
• Simple Effects — Delay/echo, tremolo, and comb-filter reverb.
• FIR Filters and Convolution — Time-domain convolution, moving-average FIR, general FIR, and FFT overlap-add fast convolution.
• Brickwall Lowpass Filter — FFT-based brickwall lowpass filter with zero transition bandwidth.
• Pitch Detection — Fundamental frequency (F0) estimation with autocorrelation and FFT peak picking.
• DTMF Tone Detection and Generation — DTMF tone detection and generation with ITU-T Q.24 timing.
• Spectrogram Text Art — Synthesise audio that displays readable text in a spectrogram.
• Shepard Tone Generator — Generate the auditory illusion of endlessly rising or falling pitch.
• Audio Steganography — Hide secret messages inside audio signals using LSB, frequency-band, or spectrogram-text encoding.
• Sample Rate Conversion — Convert signals between sample rates using a polyphase sinc resampler.
• Voice Activity Detection — Voice activity detection with adaptive feature normalization and onset/hangover smoothing.
• Error Handling — Configurable error handler, error codes, safe defaults, and custom handler installation.

Tools

Standalone programs built on the miniDSP library.

• mel_viz -- Mel-Spectrum Audio Visualizer — Mel-spectrum audio visualizer with browser-based radial animation, live mic mode, and configurable color palettes.
• resample -- Sample Rate Converter — Sample rate conversion CLI using polyphase sinc interpolation.