import type { SynthRecipe } from './timeline-types.js';
export declare const SYNTH_SAMPLE_RATE = 48000;
/** Render a recipe to mono float samples in [-1, 1], faded at both ends. */
export declare function synthesizeSamples(recipe: SynthRecipe): Float32Array;
/** Encode mono float samples as a 48kHz 16-bit PCM WAV file. */
export declare function samplesToWav(samples: Float32Array): Buffer;
export declare function synthesizeWav(recipe: SynthRecipe): Buffer;
/** Stable cache key for a recipe (16 hex chars of sha256 over its JSON). */
export declare function recipeHash(recipe: SynthRecipe): string;