/usr/ is in libavformat-dev 7:3.4.2-2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/doc/
/usr/include/
/usr/include/x86_64-linux-gnu/
/usr/include/x86_64-linux-gnu/libavformat/
/usr/include/x86_64-linux-gnu/libavformat/avformat.h
/usr/include/x86_64-linux-gnu/libavformat/avio.h
/usr/include/x86_64-linux-gnu/libavformat/version.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/libavformat.a
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/libavformat.pc
/usr/share/
/usr/share/doc/libavformat-dev/
/usr/share/doc/libavformat-dev/copyright
/usr/lib/x86_64-linux-gnu/libavformat.so
/usr/share/doc/libavformat-dev/changelog.Debian.gz