/**
 *
 * @param {Int16Array} data
 * @returns
 */
export function alawFromPCM(data: Int16Array | Int8Array): Uint8Array;
/**
 * Convert an A-law value to linear PCM
 * @param {Int16Array} data
 * @returns
 */
export function alawToPCM(data: Uint8Array, bit?: number): Int8Array;
export const ulaw_to_linear: any[];
/**
 *
 * @param {Int8Array} data
 * @returns
 */
export function ulawToPCM(data: Uint8Array, bit?: number): Int8Array;
/**
 *
 * @param { Int16Array or Int8Array } data
 */
export function ulawFromPCM(data: Int16Array | Int8Array): Uint8Array;
export type NumChannels = 1 | 2;
export type SampleBits = 8 | 16;
export type SampleRate = 8000 | 11025 | 16000 | 22050 | 24000 | 44100 | 48000;
/**
 * 编码wav，一般wav格式是在pcm文件前增加44个字节的文件头，
 * 所以，此处只需要在pcm数据前增加下就行了。
 *
 * @param {DataView} bytes           pcm二进制数据
 * @param {number}  sampleRate  输入采样率
 * @param {number}  numChannels      声道数
 * @param {number}  sampleBits  输出采样位数
 * @param {boolean} littleEndian      是否是小端字节序
 * @returns {ArrayBuffer}               wav二进制数据
 */
export function encodeWAV(bytes: DataView, sampleRate?: SampleRate, numChannels?: NumChannels, sampleBits?: SampleBits, littleEndian?: boolean): ArrayBuffer;