1FFmpeg: 2------- 3 4Most files in FFmpeg are under the GNU Lesser General Public License version 2.1 5or later (LGPL v2.1+). Read the file COPYING.LGPLv2.1 for details. Some other 6files have MIT/X11/BSD-style licenses. In combination the LGPL v2.1+ applies to 7FFmpeg. 8 9Some optional parts of FFmpeg are licensed under the GNU General Public License 10version 2 or later (GPL v2+). See the file COPYING.GPLv2 for details. None of 11these parts are used by default, you have to explicitly pass --enable-gpl to 12configure to activate them. In this case, FFmpeg's license changes to GPL v2+. 13 14Specifically, the GPL parts of FFmpeg are 15 16- libpostproc 17- some x86 optimizations in libswscale 18- optional x86 optimizations in the files 19 libavcodec/x86/h264_deblock_sse2.asm 20 libavcodec/x86/h264_idct_sse2.asm 21 libavcodec/x86/idct_mmx.c 22- the X11 grabber in libavdevice/x11grab.c 23 24There are a handful of files under other licensing terms, namely: 25 26* The files libavcodec/jfdctfst.c, libavcodec/jfdctint.c, libavcodec/jrevdct.c 27 are taken from libjpeg, see the top of the files for licensing details. 28 29Should you, for whatever reason, prefer to use version 3 of the (L)GPL, then 30the configure parameter --enable-version3 will activate this licensing option 31for you. Read the file COPYING.LGPLv3 or, if you have enabled GPL parts, 32COPYING.GPLv3 to learn the exact legal terms that apply in this case. 33 34 35external libraries: 36------------------- 37 38Some external libraries, e.g. libx264, are under GPL and can be used in 39conjunction with FFmpeg. They require --enable-gpl to be passed to configure 40as well. 41 42The OpenCORE external libraries are under the Apache License 2.0. That license 43is incompatible with the LGPL v2.1 and the GPL v2, but not with version 3 of 44those licenses. So to combine the OpenCORE libraries with FFmpeg, the license 45version needs to be upgraded by passing --enable-version3 to configure. 46 47The nonfree external libraries libamrnb, libamrwb and libfaac can be hooked up 48in FFmpeg. You need to pass --enable-nonfree to configure to enable them. Employ 49this option with care as FFmpeg then becomes nonfree and unredistributable. 50Note that libfaac claims to be LGPL, but is not. 51