feat(core): pitch shift — a granular shifter as the fifth FX worklet - #3276
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vanceingalls wants to merge 1 commit into
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feat(core): pitch shift — a granular shifter as the fifth FX worklet#3276vanceingalls wants to merge 1 commit into
vanceingalls wants to merge 1 commit into
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Adds hf-pitchshift alongside the four existing dynamics worklets: a dual-tap granular delay line, 100 ms grain, taps 180° apart so one is always crossfading in as the other resets — hides the splice each tap makes on wrap. Read-tap speed relative to the write head tracks the semitone ratio, so pitch shifts without changing duration. Registered through the same workletBuilder/dispose-message path the other four use (so shapeOf never rebuilds on a param tweak, and a chain drop retires it), wired into the registry with a plain-language copy entry and a ~0.2s chain tail (two grains). One implementation, shared by preview (Web Audio in the page) and render (the same worklet run inside an OfflineAudioContext in the headless browser) — confirmed by a browser-render test that measures the actual output frequency, not just that it differs from input. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
This was referenced Aug 14, 2026
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Summary
hf-pitchshift, a fifth AudioWorklet FX processor alongside compressor/limiter/gate/bitcrush: a dual-tap granular delay line (100 ms grain, taps 180° apart) that shifts pitch without changing playback duration.audioFx.ts), the graph builder (audioFxGraph.ts, sameworkletBuilder/dispose-message contract as the other four worklets), plain-language copy (audioFxCopy.ts, no speech words per the audit test), and the chain-tail model (audioFxTail.ts, ~0.2s for two grains).OfflineAudioContextin the headless browser) — no separate ffmpeg filter needed, matching how the other four worklet effects already work.nodeTail's switch into small per-effect helper functions while adding thepitchshiftcase, to keep it under the complexity threshold (fallow was already close before this change).Test plan
bun run build(regeneratespackages/core/src/generated/audio-fx-runtime-inline.tsfrom source — never hand-edited)cd packages/core && bun run test— 2344/2344 pass, including newHfPitchshiftunit tests (semitones:0 exact passthrough at the grain/2 delay, semitones:±12 octave shift via zero-crossing frequency estimate)cd packages/engine && bunx vitest run src/services/audioFxRender.test.ts— 16/16 pass, including a new browser-render test that measures the actual output frequency after an octave-up shift (proves render/preview parity empirically, not just structurally)cd packages/engine && bun run test— 1527 passed, 3 skipped (pre-existing), no regressionsbunx oxfmt/bunx oxlintclean on all touched filesStacks on #3275 (A2) and #3274 (A1) — should merge after both.
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