声音响应信号

<!-- motion-registry-context:{"format":"1.0.0","recipe_id":"mixed.audio-reactive-signal","recipe_version":"0.2.0","recipe_source":"recipes/mixed/audio-reactive-signal/recipe.yaml"} -->
# Motion Registry Context

<!-- motion-registry-section:recipe-identity:start -->
## Recipe identity
- Recipe ID: mixed.audio-reactive-signal
- Schema version: 0.2.0
- Recipe source: recipes/mixed/audio-reactive-signal/recipe.yaml
<!-- motion-registry-section:recipe-identity:end -->

<!-- motion-registry-section:motion-intent:start -->
## Motion intent and scope
- Purpose (zh): 预提取的声音幅度序列驱动一条信号路径、局部光晕和内容卡的有限响应。
- Purpose (en): A pre-extracted audio-amplitude sequence drives a bounded signal path, local glow, and content-card response.
- Scope: effect
- Complexity: advanced
- Subjects: mixed, shape
- Intents: emphasize, explain
- Use cases: knowledge-video, social-video, presentation, storytelling
- Recipe capabilities: precomputed-amplitudes, waveform-path, bounded-response, deterministic-audio-motion
<!-- motion-registry-section:motion-intent:end -->

<!-- motion-registry-section:inputs:start -->
## Inputs
- amplitude_frames: number-list (required; default=[0.12,0.22,0.44,0.31,0.68,0.48,0.78,0.36,0.54,0.84,0.42,0.28,0.62,0.38,0.18]) — Normalized pre-extracted amplitude samples in source order.
- headline: string (required; default=Let the signal carry the thought) — Content headline carried by the responding card.
- signal_label: string (required; default=VOICE ENERGY) — Small label describing the audio source.
<!-- motion-registry-section:inputs:end -->

<!-- motion-registry-section:normalized-timeline:start -->
## Normalized motion timeline (0 to 1)
- 0.06–0.20 · signal.fade · opacity.fade → signal · parameters={"from":0,"to":1}
- 0.16–0.72 · signal.draw · path.draw → signal · parameters={"from":0,"to":1}
- 0.20–0.44 · card.settle · spring.settle → card · parameters={"from":0.9,"to":1,"strength":"subtle"}
- 0.32–0.82 · card.response · transform.scale → card · parameters={"from":1,"to":1.04}
- 0.88–1.00 · signal.hold · state.hold → signal · parameters={}
<!-- motion-registry-section:normalized-timeline:end -->

<!-- motion-registry-section:output-envelope:start -->
## Output envelope
- Aspect ratios: 16:9, 9:16, 1:1
- Duration: min 3s; preferred 3.8s; max 5s
<!-- motion-registry-section:output-envelope:end -->

<!-- motion-registry-section:acceptance:start -->
## Acceptance constraints
- input-driven: Signal geometry and response intensity derive only from the finite amplitude input.
- bounded-motion: Content-card scaling remains subtle and readable rather than becoming a generic equalizer.
- deterministic-hold: The final frame reflects the last deterministic input sample and then remains still.
- no-runtime-analysis: Rendering requires no Web Audio, timers, random values, or network request.
<!-- motion-registry-section:acceptance:end -->

<!-- motion-registry-section:handoff-invariants:start -->
## Handoff invariants
- Preserve the subject, input meaning, event order, overlaps, final state, and approximate normalized timing.
- Keep the implementation deterministic and retain a readable, stable final hold.
- Treat the Recipe document as the source of truth; do not infer engine APIs in this shared core.
<!-- motion-registry-section:handoff-invariants:end -->