Error: libavcodec-ffmpeg.so.56: undefined symbol: av_packet_free when installing python arcade package

i am trying to 'import arcade' which is a python module which can be found at https://arcade.academy/... one of the dependencies are ffmpeg. but whenver i try to run the code, it gies the error of "AttributeError: /usr/lib/x86_64-linux-gnu/libavcodec-ffmpeg.so.56: undefined symbol: av_packet_free"..

how should i go about fixing it?