feat: add MIDI harmonizer for chord-aware melody processing#4313
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ogabrielluiz wants to merge 8 commits intoSynthstromAudible:mainfrom
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feat: add MIDI harmonizer for chord-aware melody processing#4313ogabrielluiz wants to merge 8 commits intoSynthstromAudible:mainfrom
ogabrielluiz wants to merge 8 commits intoSynthstromAudible:mainfrom
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Hey just fyi this PR will need to be rebased to the main branch as the community branch is now obsolete. Thanks! |
Add standalone harmonizer library that maps incoming MIDI melody notes to chord tones using configurable snap modes (Nearest, RoundDown, RoundUp, Root, Root5th), target tightness levels (ChordTones, Scale, Extensions, Loose), optional voice leading, diatonic intervals, and per-note probability. The engine is self-contained with no firmware dependencies beyond standard C++.
Wire the harmonizer engine into the Deluge firmware: - MidiInstrument processes melody notes through the harmonizer, applying chord-based harmonization with configurable probability, interval offsets, retrigger, and latch behavior - InstrumentClip stores per-clip HarmonizerSettings with XML serialization (read/write) and transpose clamping to [-24, 24] - PlaybackHandler resets harmonizer state on playback stop - Register MidiHarmonizer as a runtime feature setting
Add 10 menu item classes for the harmonizer submenu accessible from MIDI/CV clips: mode, tightness, interval, transpose, chord channel, probability, voice leading, retrigger, interval velocity, and latch. Each item includes null-guard safety checks and runtime feature gating. Register all harmonizer menu items in the sound editor, add l10n strings for both OLED and 7-segment displays, and wire up the submenu navigation.
Comprehensive CppUTest suite covering: - ChordState and ChannelState data structures - All 5 snap modes (Nearest, RoundDown, RoundUp, Root, Root5th) - All 4 target tightness levels (ChordTones, Scale, Extensions, Loose) - Voice leading behavior and diatonic interval computation - Multi-clip isolation, chord channel changes, mapping lifecycle - Boundary conditions (MIDI notes 0/127, empty chords, overflow) 86 tests, 254 checks, all passing.
Add comprehensive documentation for the MIDI harmonizer feature covering setup, snap modes, target tightness, voice leading, diatonic intervals, chord channel configuration, and all harmonizer parameters.
The ARM cross-compiler deduces conflicting types (long vs int) for std::clamp when mixing int32_t with integer literals. Use explicit std::clamp<int32_t> to resolve the ambiguity.
The generated g_english.cpp and g_seven_segment.cpp had 14 harmonizer strings that were missing from the source JSON files, causing the CI build to fail when the generator reproduced shorter files. Add the missing entries to both english.json and seven_segment.json and regenerate the cpp files.
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Adds a MIDI harmonizer that snaps melody notes to chord tones in real-time,
enabling chord-aware harmonization across MIDI/CV clips. A dedicated chord
channel feeds chord data while melody channels are harmonized according to
configurable rules — all per-clip with XML persistence.
Key Features
Usage
Architecture
The harmonizer engine (
midi_harmonizer.cpp/h) is a standalone library withno firmware dependencies beyond standard C++, making it independently testable.
mappings, and voice leading state
harmonizer_settings.h): lightweight POD configstored per-clip with XML serialization
MidiInstrumentintercepts note-on/off and routes throughthe harmonizer;
InstrumentCliphandles persistence;PlaybackHandlerresets state on stop
Functional Areas Affected
io/midi/midi_harmonizer.cpp/h,harmonizer_settings.hgui/menu_item/harmonizer/*.h(10 files)gui/ui/sound_editor.cpp/h,menus.cpp/hl10n/english.json,seven_segment.json,strings.h, generated filesmodel/instrument/midi_instrument.cppmodel/clip/instrument_clip.cpp/hplayback/playback_handler.cppmodel/settings/runtime_feature_settings.cpp/hTesting
leading, diatonic intervals, multi-clip isolation, chord channel switching,
mapping lifecycle, and MIDI boundary conditions
Test Plan