diff --git a/danmu_api/utils/codec-util.js b/danmu_api/utils/codec-util.js
index a112186..1756091 100644
--- a/danmu_api/utils/codec-util.js
+++ b/danmu_api/utils/codec-util.js
@@ -437,7 +437,7 @@ function pkcs7Unpad(data){
 }
 
 // ====================== Base64 解码 ======================
-function base64ToBytes(b64) {
+export function base64ToBytes(b64) {
   // 先把 Base64 字符串转换成普通字符
   const binaryString = (typeof atob === 'function')
     ? atob(b64) // 浏览器环境
@@ -581,7 +581,7 @@ function str2bytes(str) {
 }
 
 // ===================== Base64 编码 =====================
-function bytesToBase64(bytes) {
+export function bytesToBase64(bytes) {
     const chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
     let result = '';
     let i;
diff --git a/danmu_api/utils/hanjutv-util.js b/danmu_api/utils/hanjutv-util.js
index ca28046..0c69292 100644
--- a/danmu_api/utils/hanjutv-util.js
+++ b/danmu_api/utils/hanjutv-util.js
@@ -1,4 +1,4 @@
-import { md5, stringToUtf8Bytes, utf8BytesToString } from "./codec-util.js";
+import { md5, stringToUtf8Bytes, utf8BytesToString, bytesToBase64, base64ToBytes } from "./codec-util.js";
 
 const HANJUTV_VERSION = "6.5.3";
 const HANJUTV_VC = "a_7980";
@@ -45,23 +45,6 @@ function utf8Decode(bytes) {
   return utf8BytesToString(bytes);
 }
 
-function bytesToBase64(bytes) {
-  if (typeof Buffer !== "undefined") return Buffer.from(bytes).toString("base64");
-
-  let binary = "";
-  for (let i = 0; i < bytes.length; i++) binary += String.fromCharCode(bytes[i]);
-  return btoa(binary);
-}
-
-function base64ToBytes(base64) {
-  if (typeof Buffer !== "undefined") return new Uint8Array(Buffer.from(base64, "base64"));
-
-  const binary = atob(base64);
-  const bytes = new Uint8Array(binary.length);
-  for (let i = 0; i < binary.length; i++) bytes[i] = binary.charCodeAt(i);
-  return bytes;
-}
-
 function xorBytes(a, b) {
   const out = new Uint8Array(a.length);
   for (let i = 0; i < a.length; i++) out[i] = a[i] ^ b[i];