import { Talk } from '../types/voice';
import { VoiceEngine } from './VoiceEngine';
export type InworldAudioEncoding = 'MP3' | 'OGG_OPUS' | 'FLAC' | 'LINEAR16' | 'WAV' | 'PCM' | 'ALAW' | 'MULAW';
export type InworldDeliveryMode = 'STABLE' | 'BALANCED' | 'CREATIVE';
/**
 * Inworld text-to-speech engine.
 */
export declare class InworldEngine implements VoiceEngine {
    private apiEndpoint;
    private model;
    private audioEncoding;
    private sampleRateHertz;
    private bitRate?;
    private speakingRate?;
    private language?;
    private deliveryMode?;
    private temperature?;
    /**
     * Set Inworld TTS API endpoint URL.
     */
    setApiEndpoint(apiUrl: string): void;
    /**
     * Set Inworld TTS model ID.
     */
    setModel(model?: string): void;
    /**
     * Set output audio encoding.
     */
    setAudioEncoding(encoding?: InworldAudioEncoding): void;
    /**
     * Set output sample rate in hertz.
     */
    setSampleRateHertz(sampleRateHertz?: number): void;
    /**
     * Set output bitrate in bps.
     */
    setBitRate(bitRate?: number): void;
    /**
     * Set speaking rate.
     */
    setSpeakingRate(speakingRate?: number): void;
    /**
     * Set optional BCP-47 language tag.
     */
    setLanguage(language?: string): void;
    /**
     * Set delivery mode for inworld-tts-2.
     */
    setDeliveryMode(deliveryMode?: InworldDeliveryMode): void;
    /**
     * Set generation temperature for non TTS-2 models.
     */
    setTemperature(temperature?: number): void;
    fetchAudio(input: Talk, speaker: string, apiKey?: string): Promise<ArrayBuffer>;
    getTestMessage(textVoiceText?: string): string;
    private createRequestBody;
    private base64ToArrayBuffer;
    private isSupportedAudioEncoding;
    private isSupportedDeliveryMode;
}