+FFmpeg:
+-------
+
Most files in FFmpeg are under the GNU Lesser General Public License version 2.1
or later (LGPL v2.1+). Read the file COPYING.LGPLv2.1 for details. Some other
files have MIT/X11/BSD-style licenses. In combination the LGPL v2.1+ applies to
Specifically, the GPL parts of FFmpeg are
- libpostproc
-- some x86 optimizations in libswscale
- optional x86 optimizations in the files
- libavcodec/x86/h264_deblock_sse2.asm
- libavcodec/x86/h264_idct_sse2.asm
libavcodec/x86/idct_mmx.c
- the X11 grabber in libavdevice/x11grab.c
+There are a handful of files under other licensing terms, namely:
+
+* The files libavcodec/jfdctfst.c, libavcodec/jfdctint.c, libavcodec/jrevdct.c
+ are taken from libjpeg, see the top of the files for licensing details.
+
+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 FFmpeg. They require --enable-gpl to be passed to configure
as well.
-The nonfree external libraries libamrnb, libamrwb and libfaac can be hooked up
-in FFmpeg. You need to pass --enable-nonfree to configure to enable them. Employ
-this option with care as FFmpeg then becomes nonfree and unredistributable.
-Note that libfaac claims to be LGPL, but is not.
-
-There are a handful of files under other licensing terms, namely:
+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 FFmpeg, the license
+version needs to be upgraded by passing --enable-version3 to configure.
-* The files libavcodec/jfdctfst.c, libavcodec/jfdctint.c, libavcodec/jrevdct.c
- are taken from libjpeg, see the top of the files for licensing details.
+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.