-* The file libavcodec/fdctref.c is copyrighted by the MPEG Software Simulation
- Group with all rights reserved. It is only used to create a DCT test program
- and not compiled into libavcodec.
+Should you, for whatever reason, prefer to use version 3 of the (L)GPL, then
+the configure parameter --enable-version3 will activate this licensing option
+for you. Read the file COPYING.LGPLv3 or, if you have enabled GPL parts,
+COPYING.GPLv3 to learn the exact legal terms that apply in this case.
+
+
+external libraries:
+-------------------
+
+Some external libraries, e.g. libx264, are under GPL and can be used in
+conjunction with Libav. They require --enable-gpl to be passed to configure
+as well.
+
+The OpenCORE external libraries are under the Apache License 2.0. That license
+is incompatible with the LGPL v2.1 and the GPL v2, but not with version 3 of
+those licenses. So to combine the OpenCORE libraries with Libav, the license
+version needs to be upgraded by passing --enable-version3 to configure.
+
+The nonfree external library libfaac can be hooked up in Libav. You need to
+pass --enable-nonfree to configure to enable it. Employ this option with care
+as Libav then becomes nonfree and unredistributable.