fix:bug

Dockerfile

@@ -1,6 +1,6 @@
 FROM python:3.9
 RUN apt-get update && \
-    apt-get install -y vim wget curl sngrep tcpflow tcpdump && \
+    apt-get install -y vim wget curl sngrep tcpflow tcpdump ffmpeg && \
     pip3 install swig cython pip setuptools --upgrade