import { Talk } from '../types/voice';
import { VoiceEngine } from './VoiceEngine';
export type XaiCodec = 'mp3' | 'wav' | 'pcm' | 'mulaw' | 'alaw';
export type XaiSampleRate = 8000 | 16000 | 22050 | 24000 | 44100 | 48000;
export type XaiBitRate = 32000 | 64000 | 96000 | 128000 | 192000;
/**
 * xAI TTS voice synthesis engine
 */
export declare class XaiEngine implements VoiceEngine {
    private language;
    private codec;
    private sampleRate;
    private bitRate;
    /**
     * Set synthesis language (BCP-47 or auto)
     */
    setLanguage(language: string): void;
    /**
     * Set output codec
     */
    setCodec(codec: XaiCodec): void;
    /**
     * Set output sample rate
     */
    setSampleRate(sampleRate: XaiSampleRate): void;
    /**
     * Set MP3 bit rate
     */
    setBitRate(bitRate: XaiBitRate): void;
    fetchAudio(input: Talk, speaker: string, apiKey?: string): Promise<ArrayBuffer>;
    getTestMessage(textVoiceText?: string): string;
}