Supported external libraries

Currently the ffmpeg-android-maker supports only external libraries in the table below. The script automatically downloads their source code and builds according to specified script arguments.

Library name	Flag to enable	Notes
libdav1d	--enable-libdav1d / -dav1d	Uses Meson build system. Certain versions of Meson can't build the library for reasons. 0.52.1 and 0.53.2 are ok.