The nonfree external library libfaac can be hooked up in FFmpeg. You need to
pass --enable-nonfree to configure to enable it. Employ this option with care
as FFmpeg then becomes nonfree and unredistributable.
-
-The libvpx external library has a license that is (L)GPL incompatible. If you
-combine it with FFmpeg the resulting binaries are unredistributable. Thus you
-need to pass --enable-nonfree to configure to enable it.