/**
 * Utility functions for handling different audio input sources
 */
import type { SpeakInput } from "../types.js";
/**
 * Validates that only one input source is provided
 */
export declare function validateSpeakInput(input: SpeakInput): void;
/**
 * Determines the audio format from a filename extension
 */
export declare function getAudioFormatFromFilename(filename: string): string;
/**
 * Attempts to detect audio format from byte signature
 */
export declare function detectAudioFormat(audioBytes: Uint8Array): string;
/**
 * Reads an audio file and returns its contents as Uint8Array
 * Only works in Node.js environment
 */
export declare function readAudioFile(filename: string): Promise<Uint8Array>;
/**
 * Converts an audio stream to bytes
 */
export declare function streamToBytes(stream: ReadableStream<Uint8Array>): Promise<Uint8Array>;
/**
 * Processes the input and returns audio bytes with format information
 */
export declare function processAudioInput(input: SpeakInput): Promise<{
    audioBytes: Uint8Array;
    mimeType: string;
}>;