Real-time chord detection: Goertzel chroma + template matching. More...
#include "../Analysis/Goertzel.h"#include "../Core/AudioBuffer.h"#include "../Core/AudioSpec.h"#include "../Core/DspMath.h"#include "../Core/WindowFunctions.h"#include "HarmonyConstants.h"#include <algorithm>#include <array>#include <atomic>#include <cmath>#include <cstdint>#include <span>#include <vector>
Go to the source code of this file.
Classes | |
| class | dspark::ChordDetector< T > |
| Monophonic-buffer chord recognition with confidence gating. More... | |
| struct | dspark::ChordDetector< T >::Result |
| One detection result. More... | |
Namespaces | |
| namespace | dspark |
| Main namespace for the DSPark framework. | |
Detailed Description
Real-time chord detection: Goertzel chroma + template matching.
Classic music-information-retrieval pipeline, allocation-free:
- A mono sum is windowed (Hann) every hop and analyzed with one exact Goertzel per note over MIDI 36..83 (four octaves) - no FFT-grid compromise at low pitches.
- Note energies fold into a 12-bin chroma vector.
- The chroma is cosine-matched against chord templates (major, minor, diminished, augmented, sus2, sus4, dom7, maj7, min7, half-dim7) at all 12 roots; the winner and its margin over the runner-up produce a confidence in [0, 1].
The reading is gated: while confidence is below the threshold the last confident chord is held, so brief transients and silences do not flicker the display.
Threading: prepare() is setup-thread only (allocates). processBlock / pushSamples and reset() belong to the thread that owns the stream. setConfidenceThreshold() may be called from any thread, and getChord() is a lock-free readout safe from any thread (single packed atomic word, never torn).
Dependencies: Goertzel.h, HarmonyConstants.h, AudioSpec.h, AudioBuffer.h, WindowFunctions.h, DspMath.h.
Definition in file ChordDetector.h.
