diff --git a/README.md b/README.md
index 50478b4..207b79c 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,13 @@
 
 详细信息和用法请见 [https://mooc.xoy.io/](https://mooc.xoy.io/)。
 
+### m3u8下载脚本使用
+依赖系统ffmpeg, 需要先安装ffmpeg，<https://www.ffmpeg.org/download.html> 在Ubuntu下已测试。
+
+```sh
+./download_m3u8.py -l 学术规范与论文写作/Videos/Videos.txt
+```
+
 ### 声明
 
 仅限个人学习和研究使用，切勿用于其他用途。强烈建议到 MOOC 网站进行学习，本程序只是提供一个备选方案。
diff --git a/download_m3u8.py b/download_m3u8.py
new file mode 100644
index 0000000..e8ef15c
--- /dev/null
+++ b/download_m3u8.py
@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+import os
+import sys
+import argparse
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description='Download m3u8 to mp4')
+    parser.add_argument('-l', default=r'', help='视频列表')
+    parser.add_argument('-d', default=r'', help='下载目录')
+    args = parser.parse_args()
+    video_list = os.path.abspath(args.l)
+
+    if args.d == '':
+        video_dir = os.path.dirname(video_list)
+    else:
+        video_dir = os.path.abspath(args.d)
+
+    with open(video_list) as f:
+        lines = f.readlines()
+        lines = [_.strip() for _ in lines if _ != '\n']
+        for line in lines:
+            name,url = line.split('\t')
+            print(name,url)
+            os.system('ffmpeg -i "{}" -c copy -bsf:a aac_adtstoasc "{}"'\
+                      .format(url,os.path.join(video_dir,name)))
\ No newline at end of file
diff --git a/mooc/icourse163.py b/mooc/icourse163.py
index 27c8514..2b1a084 100644
--- a/mooc/icourse163.py
+++ b/mooc/icourse163.py
@@ -3,6 +3,7 @@
 
 import time
 from .utils import *
+import json
 
 CANDY = Crawler()
 CONFIG = {}
@@ -11,21 +12,21 @@
 
 def get_summary(url):
     """从课程主页面获取信息"""
+    res = CANDY.get(url)
+    cookie_csrf = res.cookies.get('NTESSTUDYSI')
+    res_t = res.text
 
-    res = CANDY.get(url).text
-
-    term_id = re.search(r'termId : "(\d+)"', res).group(1)
-    names = re.findall(r'name:"(.+)"', res)
+    term_id = re.search(r'termId : "(\d+)"', res_t).group(1)
+    names = re.findall(r'name:"(.+)"', res_t)
 
     dir_name = course_dir(*names[:2])
 
     print(dir_name)
-    return term_id, dir_name
+    return term_id, dir_name, cookie_csrf
 
 
 def parse_resource(resource):
     """解析资源地址和下载资源"""
-
     post_data = {'callCount': '1', 'scriptSessionId': '${scriptSessionId}190',
                  'httpSessionId': '5531d06316b34b9486a6891710115ebc', 'c0-scriptName': 'CourseBean',
                  'c0-methodName': 'getLessonUnitLearnVo', 'c0-id': '0', 'c0-param0': 'number:' + resource.meta[0],
@@ -34,21 +35,28 @@ def parse_resource(resource):
     res = CANDY.post('https://www.icourse163.org/dwr/call/plaincall/CourseBean.getLessonUnitLearnVo.dwr',
                      data=post_data).text
 
+
     file_name = resource.file_name
     if resource.type == 'Video':
-        resolutions = ['Shd', 'Hd', 'Sd']
-        for sp in resolutions[CONFIG['resolution']:]:
-            # TODO: 增加视频格式选择
-            # video_info = re.search(r'%sUrl="(?P<url>.*?(?P<ext>\.((m3u8)|(mp4)|(flv))).*?)"' % sp, res)
-            video_info = re.search(r'(?P<ext>mp4)%sUrl="(?P<url>.*?\.(?P=ext).*?)"' % sp, res)
-            if video_info:
-                url, ext = video_info.group('url', 'ext')
-                ext = '.' + ext
-                break
-        res_print(file_name + ext)
-        FILES['renamer'].write(re.search(r'(\w+\.((m3u8)|(mp4)|(flv)))', url).group(1), file_name, ext)
-        FILES['video'].write_string(url)
-        resource.ext = ext
+        post_data = {'bizId': resource.meta[2],
+                     'bizType': '1',
+                     'contentType': '1'}
+        url = 'https://www.icourse163.org/web/j/resourceRpcBean.getResourceToken.rpc?csrfKey={}'.format(CONFIG['_cookie_csrf'])
+        res = CANDY.post(url,data=post_data).text
+        res_json = json.loads(res)
+        if res_json.get('code', -1) != 0:
+            print('get signature error.')
+            return
+        sig = res_json['result']['videoSignDto']['signature']
+
+        url = 'https://vod.study.163.com/eds/api/v1/vod/video?videoId={}&signature={}&clientType=1'.format(resource.meta[0], sig)
+        res = CANDY.get(url).text
+        res_json = json.loads(res)
+        url = res_json['result']['videos'][-1]['videoUrl']
+        name = res_json['result']['name']
+        FILES['video'].write_string('{}\t{}'.format(name,url))
+        res_print('{}\t{}'.format(name, url))
+
 
         if not CONFIG['sub']:
             return
@@ -165,7 +173,8 @@ def start(url, config):
     global WORK_DIR
 
     CONFIG.update(config)
-    term_id, dir_name = get_summary(url)
+    term_id, dir_name, cookie_csrf = get_summary(url)
+    CONFIG['_cookie_csrf'] = cookie_csrf
 
     WORK_DIR = WorkingDir(CONFIG['dir'], dir_name)
     WORK_DIR.change('Videos')