List of best mirrors for IP address 18.191.171.10, located in an unknown country.
I am very sorry, but no mirror was found. Feel free to download directly:
http://mirrordirector-mb.raspbian.org/multiarch/pool/main/f/ffmpeg/libavformat-extra58-dbgsym_4.4.1-3+rpi1+b2_arm64.deb