diff --git a/biz/ffmpeg.py b/biz/ffmpeg.py
index 0106458..fecb5a3 100644
--- a/biz/ffmpeg.py
+++ b/biz/ffmpeg.py
@@ -110,9 +110,9 @@ def start_ffmpeg_task(ffmpeg_task):
                 return False
         ffmpeg_task.correct_task_type()
         span.set_attribute("task.type", ffmpeg_task.task_type)
-        span.set_attribute("task.center_cut", ffmpeg_task.center_cut)
+        span.set_attribute("task.center_cut", str(ffmpeg_task.center_cut))
         span.set_attribute("task.frame_rate", ffmpeg_task.frame_rate)
-        span.set_attribute("task.resolution", ffmpeg_task.resolution)
+        span.set_attribute("task.resolution", str(ffmpeg_task.resolution))
         span.set_attribute("task.ext_data", json.dumps(ffmpeg_task.ext_data))
         result = ffmpeg.start_render(ffmpeg_task)
         if not result: