import type { Talk } from '../types/voice';
import type { VoiceEngine } from './VoiceEngine';
export interface PiperPlusAssets {
    /** Base path where piper assets are served (e.g. '/piper/' or 'https://example.com/piper/'). Must end with '/'. */
    basePath: string;
    /** Model config JSON filename relative to basePath + 'models/' (e.g. 'tsukuyomi-config.json') */
    modelConfigFile: string;
    /** ONNX model filename relative to basePath + 'models/' (e.g. 'tsukuyomi-wavlm-300epoch.onnx') */
    modelFile: string;
    /** HTS voice filename relative to basePath + 'assets/voice/' (e.g. 'mei_normal.htsvoice') */
    voiceFile: string;
}
/**
 * WASM-based Japanese TTS engine powered by ONNX Runtime Web and OpenJTalk.
 *
 * This engine is intended for browser-only execution.
 */
export declare class PiperPlusEngine implements VoiceEngine {
    private phonemizer;
    private onnxSession;
    private modelConfig;
    private initialized;
    private initPromise;
    private assets?;
    private speed;
    private noiseScale;
    static isAvailable(): boolean;
    setAssets(assets: PiperPlusAssets): void;
    /**
     * Set the speaking speed multiplier.
     *
     * Valid range is 0.5 to 2.0. The default value is 1.0.
     */
    setSpeed(speed?: number): void;
    /**
     * Set the synthesis noise scale.
     *
     * Valid range is 0.0 to 2.0. The default value is 1.0.
     */
    setNoiseScale(noiseScale?: number): void;
    initialize(): Promise<void>;
    fetchAudio(input: Talk, speaker: string, apiKey?: string): Promise<ArrayBuffer>;
    dispose(): Promise<void>;
    getTestMessage(textVoiceText?: string): string;
    private requireAssets;
    private requireModelConfig;
    private requirePhonemizer;
    private requireOnnxSession;
}
export declare function float32ToWav(samples: Float32Array, sampleRate: number): ArrayBuffer;