diff --git a/dist/hls2mp4.cjs b/dist/hls2mp4.cjs
index 106c66f..b832913 100644
--- a/dist/hls2mp4.cjs
+++ b/dist/hls2mp4.cjs
@@ -914,7 +914,7 @@ function parseM3u8File(url, customFetch) {
                 case 1:
                     playList = _a.sent();
                     return [3 /*break*/, 4];
-                case 2: return [4 /*yield*/, ffmpeg.fetchFile(url).then(function (data) { return new Blob([data.buffer]).text(); })];
+                case 2: return [4 /*yield*/, ffmpeg.fetchFile(url).then(function (data) { return aesjs.utils.utf8.fromBytes(data); })];
                 case 3:
                     playList = _a.sent();
                     _a.label = 4;
@@ -957,7 +957,11 @@ var Hls2Mp4 = /** @class */ (function () {
         return buffer.slice(bufferOffset);
     };
     Hls2Mp4.prototype.hexToUint8Array = function (hex) {
-        return new Uint8Array(hex.replace(/^0x/, '').match(/[\da-f]{2}/gi).map(function (hx) { return parseInt(hx, 16); }));
+        var matchedChars = hex.replace(/^0x/, '').match(/[\da-f]{2}/gi);
+        if (matchedChars) {
+            return new Uint8Array(matchedChars.map(function (hx) { return parseInt(hx, 16); }));
+        }
+        return new Uint8Array(0);
     };
     Hls2Mp4.prototype.aesDecrypt = function (buffer, keyBuffer, iv) {
         var ivData;
@@ -982,7 +986,7 @@ var Hls2Mp4 = /** @class */ (function () {
                             (_b = this.onProgress) === null || _b === void 0 ? void 0 : _b.call(this, exports.TaskType.parseM3u8, 1);
                             return [2 /*return*/, data];
                         }
-                        return [2 /*return*/];
+                        throw new Error('m3u8 load failed');
                 }
             });
         });
@@ -1037,13 +1041,14 @@ var Hls2Mp4 = /** @class */ (function () {
     };
     Hls2Mp4.prototype.downloadM3u8 = function (url) {
         return __awaiter(this, void 0, void 0, function () {
-            var _a, content, parsedUrl, keyMatchRegExp, keyTagMatchRegExp, matchReg, matches, segments, i, matched, matchedKey, matchedIV, batch, treatedSegments, segments_1, segments_1_1, group, total, keyBuffer, keyUrl, _loop_1, this_1, i, e_1_1, m3u8;
+            var m3u8Parsed, _a, content, parsedUrl, keyMatchRegExp, keyTagMatchRegExp, matchReg, matches, segments, i, matched, matchedKey, matchedIV, batch, treatedSegments, segments_1, segments_1_1, group, total, keyBuffer, keyUrl, _loop_1, this_1, i, e_1_1, m3u8;
             var e_1, _b;
             return __generator(this, function (_c) {
                 switch (_c.label) {
                     case 0: return [4 /*yield*/, this.parseM3u8(url)];
                     case 1:
-                        _a = _c.sent(), content = _a.content, parsedUrl = _a.url;
+                        m3u8Parsed = _c.sent();
+                        _a = m3u8Parsed, content = _a.content, parsedUrl = _a.url;
                         keyMatchRegExp = createFileUrlRegExp('key', 'gi');
                         keyTagMatchRegExp = new RegExp('#EXT-X-KEY:METHOD=(AES-128|NONE)(,URI="' + keyMatchRegExp.source + '"(,IV=\\w+)?)?', 'gi');
                         matchReg = new RegExp(keyTagMatchRegExp.source + '|' + createFileUrlRegExp('ts', 'gi').source, 'g');
@@ -1189,7 +1194,7 @@ var Hls2Mp4 = /** @class */ (function () {
                         }
                         return [2 /*return*/, {
                                 done: false,
-                                data: null
+                                data: undefined
                             }];
                     case 3: return [2 /*return*/];
                 }
@@ -1251,7 +1256,7 @@ var Hls2Mp4 = /** @class */ (function () {
         anchor.click();
         setTimeout(function () { return URL.revokeObjectURL(objectUrl); }, 100);
     };
-    Hls2Mp4.version = '1.1.5';
+    Hls2Mp4.version = '1.1.7';
     return Hls2Mp4;
 }());
 
diff --git a/dist/hls2mp4.js b/dist/hls2mp4.js
index f6b9bbe..12add18 100644
--- a/dist/hls2mp4.js
+++ b/dist/hls2mp4.js
@@ -911,7 +911,7 @@
                     case 1:
                         playList = _a.sent();
                         return [3 /*break*/, 4];
-                    case 2: return [4 /*yield*/, ffmpeg.fetchFile(url).then(function (data) { return new Blob([data.buffer]).text(); })];
+                    case 2: return [4 /*yield*/, ffmpeg.fetchFile(url).then(function (data) { return aesjs.utils.utf8.fromBytes(data); })];
                     case 3:
                         playList = _a.sent();
                         _a.label = 4;
@@ -954,7 +954,11 @@
             return buffer.slice(bufferOffset);
         };
         Hls2Mp4.prototype.hexToUint8Array = function (hex) {
-            return new Uint8Array(hex.replace(/^0x/, '').match(/[\da-f]{2}/gi).map(function (hx) { return parseInt(hx, 16); }));
+            var matchedChars = hex.replace(/^0x/, '').match(/[\da-f]{2}/gi);
+            if (matchedChars) {
+                return new Uint8Array(matchedChars.map(function (hx) { return parseInt(hx, 16); }));
+            }
+            return new Uint8Array(0);
         };
         Hls2Mp4.prototype.aesDecrypt = function (buffer, keyBuffer, iv) {
             var ivData;
@@ -979,7 +983,7 @@
                                 (_b = this.onProgress) === null || _b === void 0 ? void 0 : _b.call(this, exports.TaskType.parseM3u8, 1);
                                 return [2 /*return*/, data];
                             }
-                            return [2 /*return*/];
+                            throw new Error('m3u8 load failed');
                     }
                 });
             });
@@ -1034,13 +1038,14 @@
         };
         Hls2Mp4.prototype.downloadM3u8 = function (url) {
             return __awaiter(this, void 0, void 0, function () {
-                var _a, content, parsedUrl, keyMatchRegExp, keyTagMatchRegExp, matchReg, matches, segments, i, matched, matchedKey, matchedIV, batch, treatedSegments, segments_1, segments_1_1, group, total, keyBuffer, keyUrl, _loop_1, this_1, i, e_1_1, m3u8;
+                var m3u8Parsed, _a, content, parsedUrl, keyMatchRegExp, keyTagMatchRegExp, matchReg, matches, segments, i, matched, matchedKey, matchedIV, batch, treatedSegments, segments_1, segments_1_1, group, total, keyBuffer, keyUrl, _loop_1, this_1, i, e_1_1, m3u8;
                 var e_1, _b;
                 return __generator(this, function (_c) {
                     switch (_c.label) {
                         case 0: return [4 /*yield*/, this.parseM3u8(url)];
                         case 1:
-                            _a = _c.sent(), content = _a.content, parsedUrl = _a.url;
+                            m3u8Parsed = _c.sent();
+                            _a = m3u8Parsed, content = _a.content, parsedUrl = _a.url;
                             keyMatchRegExp = createFileUrlRegExp('key', 'gi');
                             keyTagMatchRegExp = new RegExp('#EXT-X-KEY:METHOD=(AES-128|NONE)(,URI="' + keyMatchRegExp.source + '"(,IV=\\w+)?)?', 'gi');
                             matchReg = new RegExp(keyTagMatchRegExp.source + '|' + createFileUrlRegExp('ts', 'gi').source, 'g');
@@ -1186,7 +1191,7 @@
                             }
                             return [2 /*return*/, {
                                     done: false,
-                                    data: null
+                                    data: undefined
                                 }];
                         case 3: return [2 /*return*/];
                     }
@@ -1248,7 +1253,7 @@
             anchor.click();
             setTimeout(function () { return URL.revokeObjectURL(objectUrl); }, 100);
         };
-        Hls2Mp4.version = '1.1.5';
+        Hls2Mp4.version = '1.1.7';
         return Hls2Mp4;
     }());
 
diff --git a/dist/hls2mp4.umd.js b/dist/hls2mp4.umd.js
index 710a721..ae71d23 100644
--- a/dist/hls2mp4.umd.js
+++ b/dist/hls2mp4.umd.js
@@ -914,7 +914,7 @@
                     case 1:
                         playList = _a.sent();
                         return [3 /*break*/, 4];
-                    case 2: return [4 /*yield*/, ffmpeg.fetchFile(url).then(function (data) { return new Blob([data.buffer]).text(); })];
+                    case 2: return [4 /*yield*/, ffmpeg.fetchFile(url).then(function (data) { return aesjs.utils.utf8.fromBytes(data); })];
                     case 3:
                         playList = _a.sent();
                         _a.label = 4;
@@ -957,7 +957,11 @@
             return buffer.slice(bufferOffset);
         };
         Hls2Mp4.prototype.hexToUint8Array = function (hex) {
-            return new Uint8Array(hex.replace(/^0x/, '').match(/[\da-f]{2}/gi).map(function (hx) { return parseInt(hx, 16); }));
+            var matchedChars = hex.replace(/^0x/, '').match(/[\da-f]{2}/gi);
+            if (matchedChars) {
+                return new Uint8Array(matchedChars.map(function (hx) { return parseInt(hx, 16); }));
+            }
+            return new Uint8Array(0);
         };
         Hls2Mp4.prototype.aesDecrypt = function (buffer, keyBuffer, iv) {
             var ivData;
@@ -982,7 +986,7 @@
                                 (_b = this.onProgress) === null || _b === void 0 ? void 0 : _b.call(this, exports.TaskType.parseM3u8, 1);
                                 return [2 /*return*/, data];
                             }
-                            return [2 /*return*/];
+                            throw new Error('m3u8 load failed');
                     }
                 });
             });
@@ -1037,13 +1041,14 @@
         };
         Hls2Mp4.prototype.downloadM3u8 = function (url) {
             return __awaiter(this, void 0, void 0, function () {
-                var _a, content, parsedUrl, keyMatchRegExp, keyTagMatchRegExp, matchReg, matches, segments, i, matched, matchedKey, matchedIV, batch, treatedSegments, segments_1, segments_1_1, group, total, keyBuffer, keyUrl, _loop_1, this_1, i, e_1_1, m3u8;
+                var m3u8Parsed, _a, content, parsedUrl, keyMatchRegExp, keyTagMatchRegExp, matchReg, matches, segments, i, matched, matchedKey, matchedIV, batch, treatedSegments, segments_1, segments_1_1, group, total, keyBuffer, keyUrl, _loop_1, this_1, i, e_1_1, m3u8;
                 var e_1, _b;
                 return __generator(this, function (_c) {
                     switch (_c.label) {
                         case 0: return [4 /*yield*/, this.parseM3u8(url)];
                         case 1:
-                            _a = _c.sent(), content = _a.content, parsedUrl = _a.url;
+                            m3u8Parsed = _c.sent();
+                            _a = m3u8Parsed, content = _a.content, parsedUrl = _a.url;
                             keyMatchRegExp = createFileUrlRegExp('key', 'gi');
                             keyTagMatchRegExp = new RegExp('#EXT-X-KEY:METHOD=(AES-128|NONE)(,URI="' + keyMatchRegExp.source + '"(,IV=\\w+)?)?', 'gi');
                             matchReg = new RegExp(keyTagMatchRegExp.source + '|' + createFileUrlRegExp('ts', 'gi').source, 'g');
@@ -1189,7 +1194,7 @@
                             }
                             return [2 /*return*/, {
                                     done: false,
-                                    data: null
+                                    data: undefined
                                 }];
                         case 3: return [2 /*return*/];
                     }
@@ -1251,7 +1256,7 @@
             anchor.click();
             setTimeout(function () { return URL.revokeObjectURL(objectUrl); }, 100);
         };
-        Hls2Mp4.version = '1.1.5';
+        Hls2Mp4.version = '1.1.7';
         return Hls2Mp4;
     }());
 
diff --git a/dist/index.js b/dist/index.js
index d15d380..0ff2135 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -910,7 +910,7 @@ function parseM3u8File(url, customFetch) {
                 case 1:
                     playList = _a.sent();
                     return [3 /*break*/, 4];
-                case 2: return [4 /*yield*/, fetchFile(url).then(function (data) { return new Blob([data.buffer]).text(); })];
+                case 2: return [4 /*yield*/, fetchFile(url).then(function (data) { return aesjs.utils.utf8.fromBytes(data); })];
                 case 3:
                     playList = _a.sent();
                     _a.label = 4;
@@ -953,7 +953,11 @@ var Hls2Mp4 = /** @class */ (function () {
         return buffer.slice(bufferOffset);
     };
     Hls2Mp4.prototype.hexToUint8Array = function (hex) {
-        return new Uint8Array(hex.replace(/^0x/, '').match(/[\da-f]{2}/gi).map(function (hx) { return parseInt(hx, 16); }));
+        var matchedChars = hex.replace(/^0x/, '').match(/[\da-f]{2}/gi);
+        if (matchedChars) {
+            return new Uint8Array(matchedChars.map(function (hx) { return parseInt(hx, 16); }));
+        }
+        return new Uint8Array(0);
     };
     Hls2Mp4.prototype.aesDecrypt = function (buffer, keyBuffer, iv) {
         var ivData;
@@ -978,7 +982,7 @@ var Hls2Mp4 = /** @class */ (function () {
                             (_b = this.onProgress) === null || _b === void 0 ? void 0 : _b.call(this, TaskType.parseM3u8, 1);
                             return [2 /*return*/, data];
                         }
-                        return [2 /*return*/];
+                        throw new Error('m3u8 load failed');
                 }
             });
         });
@@ -1033,13 +1037,14 @@ var Hls2Mp4 = /** @class */ (function () {
     };
     Hls2Mp4.prototype.downloadM3u8 = function (url) {
         return __awaiter(this, void 0, void 0, function () {
-            var _a, content, parsedUrl, keyMatchRegExp, keyTagMatchRegExp, matchReg, matches, segments, i, matched, matchedKey, matchedIV, batch, treatedSegments, segments_1, segments_1_1, group, total, keyBuffer, keyUrl, _loop_1, this_1, i, e_1_1, m3u8;
+            var m3u8Parsed, _a, content, parsedUrl, keyMatchRegExp, keyTagMatchRegExp, matchReg, matches, segments, i, matched, matchedKey, matchedIV, batch, treatedSegments, segments_1, segments_1_1, group, total, keyBuffer, keyUrl, _loop_1, this_1, i, e_1_1, m3u8;
             var e_1, _b;
             return __generator(this, function (_c) {
                 switch (_c.label) {
                     case 0: return [4 /*yield*/, this.parseM3u8(url)];
                     case 1:
-                        _a = _c.sent(), content = _a.content, parsedUrl = _a.url;
+                        m3u8Parsed = _c.sent();
+                        _a = m3u8Parsed, content = _a.content, parsedUrl = _a.url;
                         keyMatchRegExp = createFileUrlRegExp('key', 'gi');
                         keyTagMatchRegExp = new RegExp('#EXT-X-KEY:METHOD=(AES-128|NONE)(,URI="' + keyMatchRegExp.source + '"(,IV=\\w+)?)?', 'gi');
                         matchReg = new RegExp(keyTagMatchRegExp.source + '|' + createFileUrlRegExp('ts', 'gi').source, 'g');
@@ -1185,7 +1190,7 @@ var Hls2Mp4 = /** @class */ (function () {
                         }
                         return [2 /*return*/, {
                                 done: false,
-                                data: null
+                                data: undefined
                             }];
                     case 3: return [2 /*return*/];
                 }
@@ -1247,7 +1252,7 @@ var Hls2Mp4 = /** @class */ (function () {
         anchor.click();
         setTimeout(function () { return URL.revokeObjectURL(objectUrl); }, 100);
     };
-    Hls2Mp4.version = '1.1.5';
+    Hls2Mp4.version = '1.1.7';
     return Hls2Mp4;
 }());
 
diff --git a/package.json b/package.json
index 0afb0f1..ac6b591 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,7 @@
     "@rollup/plugin-node-resolve": "^15.0.2",
     "@rollup/plugin-commonjs": "^25.0.0",
     "@rollup/plugin-typescript": "^11.1.0",
+    "@types/aes-js": "^3.1.1",
     "rollup": "^3.21.4",
     "tslib": "^2.0.0",
     "typescript": "^4.7.4"
diff --git a/src/index.ts b/src/index.ts
index f26cf74..fdf9e13 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,5 +1,5 @@
 import { createFFmpeg, fetchFile, CreateFFmpegOptions, FFmpeg } from '@ffmpeg/ffmpeg';
-import aesjs from 'aes-js';
+import aesjs, { type ByteSource } from 'aes-js';
 
 export enum TaskType {
     loadFFmeg = 0,
@@ -14,7 +14,7 @@ interface ProgressCallback {
 
 type LoadResult<T = unknown> = {
     done: boolean;
-    data: T;
+    data?: T;
     msg?: string;
 }
 
@@ -64,7 +64,7 @@ export async function parseM3u8File(url: string, customFetch?: (url: string) =>
     }
     else {
         playList = await fetchFile(url).then(
-            data => new Blob([data.buffer]).text()
+            data => aesjs.utils.utf8.fromBytes(data)
         )
     }
     const matchedM3u8 = playList.match(
@@ -89,7 +89,7 @@ export default class Hls2Mp4 {
     private tsDownloadConcurrency: number;
     private totalSegments = 0;
     private savedSegments = 0;
-    public static version = '1.1.5'
+    public static version = '1.1.7'
 
     constructor({ maxRetry = 3, tsDownloadConcurrency = 10, ...options }: CreateFFmpegOptions & Hls2Mp4Options, onProgress?: ProgressCallback) {
         this.instance = createFFmpeg(options);
@@ -114,18 +114,23 @@ export default class Hls2Mp4 {
     }
 
     private hexToUint8Array(hex: string) {
-        return new Uint8Array(
-            hex.replace(/^0x/, '').match(
-                /[\da-f]{2}/gi
-            ).map(hx => parseInt(hx, 16)))
+        const matchedChars = hex.replace(/^0x/, '').match(
+            /[\da-f]{2}/gi
+        );
+        if (matchedChars) {
+            return new Uint8Array(
+                matchedChars.map(hx => parseInt(hx, 16))
+            )
+        }
+        return new Uint8Array(0);
     }
 
     private aesDecrypt(buffer: Uint8Array, keyBuffer: Uint8Array, iv?: string) {
-        let ivData: Uint8Array;
+        let ivData: ByteSource;
         if (iv) {
             ivData = iv.startsWith('0x') ? this.hexToUint8Array(iv) : aesjs.utils.utf8.toBytes(iv)
         }
-        const aesCbc = new aesjs.ModeOfOperation.cbc(keyBuffer, ivData);
+        const aesCbc = new aesjs.ModeOfOperation.cbc(keyBuffer, ivData!);
         return aesCbc.decrypt(buffer);
     }
 
@@ -138,7 +143,7 @@ export default class Hls2Mp4 {
             this.onProgress?.(TaskType.parseM3u8, 1)
             return data;
         }
-        new Error('m3u8 load failed')
+        throw new Error('m3u8 load failed')
     }
 
     private async downloadFile(url: string) {
@@ -156,7 +161,7 @@ export default class Hls2Mp4 {
         return Promise.all(
             segs.map(async ({ name, url, source }) => {
                 const tsData = await this.downloadFile(url)
-                const buffer = key ? this.aesDecrypt(tsData, key, iv) : this.transformBuffer(tsData)
+                const buffer = key ? this.aesDecrypt(tsData!, key, iv) : this.transformBuffer(tsData!)
                 this.instance.FS('writeFile', name, buffer)
                 this.savedSegments += 1
                 this.onProgress?.(TaskType.downloadTs, this.savedSegments / this.totalSegments)
@@ -170,7 +175,8 @@ export default class Hls2Mp4 {
     }
 
     private async downloadM3u8(url: string) {
-        let { content, url: parsedUrl } = await this.parseM3u8(url)
+        const m3u8Parsed = await this.parseM3u8(url)
+        let { content, url: parsedUrl } = m3u8Parsed!;
         const keyMatchRegExp = createFileUrlRegExp('key', 'gi');
         const keyTagMatchRegExp = new RegExp(
             '#EXT-X-KEY:METHOD=(AES-128|NONE)(,URI="' + keyMatchRegExp.source + '"(,IV=\\w+)?)?',
@@ -215,7 +221,7 @@ export default class Hls2Mp4 {
 
         for (const group of segments) {
             const total = group.segments.length;
-            let keyBuffer: Uint8Array;
+            let keyBuffer: Uint8Array | undefined;
 
             if (group.key) {
                 const keyUrl = parseUrl(parsedUrl, group.key)
@@ -270,7 +276,7 @@ export default class Hls2Mp4 {
             }
             return {
                 done: false,
-                data: null
+                data: undefined
             }
         }
     }
diff --git a/tsconfig.json b/tsconfig.json
index 0d56441..0056f02 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -10,7 +10,7 @@
         "outDir": "dist",
         "allowJs": true,
         "skipLibCheck": true,
-        "strict": false,
+        "strict": true,
         "forceConsistentCasingInFileNames": true,
         "noEmit": true,
         "esModuleInterop": true,
diff --git a/yarn.lock b/yarn.lock
index 499b68b..15a8832 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -63,6 +63,11 @@
     estree-walker "^2.0.2"
     picomatch "^2.3.1"
 
+"@types/aes-js@^3.1.1":
+  version "3.1.1"
+  resolved "https://registry.yarnpkg.com/@types/aes-js/-/aes-js-3.1.1.tgz#34b3978122310c135de4b377270d1d65676fae28"
+  integrity sha512-SDSGgXT3LRCH6qMWk8OHT1vLSVNuHNvCpKCx2/TYtQMbMGGgxJC9fspwSkQjqzRagrWnCrxuLL3jMNXLXHHvSw==
+
 "@types/estree@*", "@types/estree@^1.0.0":
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/@types/estree/-/estree-1.0.1.tgz#aa22750962f3bf0e79d753d3cc067f010c95f194"