fix: 修复获取预览参数

client.py

@@ -20,6 +20,10 @@ class HikVisionClient(object):
         self.https = https
         self.url = '{}://{}:{}'.format('https' if https else 'http', self.host, self.port)
 
+    @staticmethod
+    def iso_format(dtime):
+        return '{}+08:00'.format(dtime.strftime('%Y-%m-%dT%H:%M:%S.%f')[:-3])
+
     def _sign(self, uri, body, method='POST'):
         content_md5 = hashlib.md5()
         content_md5.update(json.dumps(body).encode('utf-8'))
@@ -71,7 +75,7 @@ class HikVisionClient(object):
             'cameraIndexCode': camera_index_code,
             'protocol': protocol,
             'streamType': stream_type,
-            'transmode': 0,
+            'transmode': 1,
             'expand': 'streamform={}'.format(streamform)
         }
         uri = "/artemis/api/video/v1/cameras/previewURLs"