3 Most files in FFmpeg are under the GNU Lesser General Public License version 2.1
4 or later (LGPL v2.1+). Read the file `COPYING.LGPLv2.1` for details. Some other
5 files have MIT/X11/BSD-style licenses. In combination the LGPL v2.1+ applies to
8 Some optional parts of FFmpeg are licensed under the GNU General Public License
9 version 2 or later (GPL v2+). See the file `COPYING.GPLv2` for details. None of
10 these parts are used by default, you have to explicitly pass `--enable-gpl` to
11 configure to activate them. In this case, FFmpeg's license changes to GPL v2+.
13 Specifically, the GPL parts of FFmpeg are:
16 - optional x86 optimizations in the files
17 - `libavcodec/x86/flac_dsp_gpl.asm`
18 - `libavcodec/x86/idct_mmx.c`
19 - `libavfilter/x86/vf_removegrain.asm`
20 - libutvideo encoding/decoding wrappers in
21 `libavcodec/libutvideo*.cpp`
22 - the X11 grabber in `libavdevice/x11grab.c`
23 - the swresample test app in
24 `libswresample/swresample-test.c`
25 - the `texi2pod.pl` tool
26 - the following filters in libavfilter:
60 Should you, for whatever reason, prefer to use version 3 of the (L)GPL, then
61 the configure parameter `--enable-version3` will activate this licensing option
62 for you. Read the file `COPYING.LGPLv3` or, if you have enabled GPL parts,
63 `COPYING.GPLv3` to learn the exact legal terms that apply in this case.
65 There are a handful of files under other licensing terms, namely:
67 * The files `libavcodec/jfdctfst.c`, `libavcodec/jfdctint_template.c` and
68 `libavcodec/jrevdct.c` are taken from libjpeg, see the top of the files for
69 licensing details. Specifically note that you must credit the IJG in the
70 documentation accompanying your program if you only distribute executables.
71 You must also indicate any changes including additions and deletions to
72 those three files in the documentation.
73 * `tests/reference.pnm` is under the expat license.
79 FFmpeg can be combined with a number of external libraries, which sometimes
80 affect the licensing of binaries resulting from the combination.
85 The following libraries are under GPL:
96 When combining them with FFmpeg, FFmpeg needs to be licensed as GPL as well by
97 passing `--enable-gpl` to configure.
99 The OpenCORE and VisualOn libraries are under the Apache License 2.0. That
100 license is incompatible with the LGPL v2.1 and the GPL v2, but not with
101 version 3 of those licenses. So to combine these libraries with FFmpeg, the
102 license version needs to be upgraded by passing `--enable-version3` to configure.
104 incompatible libraries
105 ----------------------
107 The Fraunhofer AAC library, FAAC and aacplus are under licenses which
108 are incompatible with the GPLv2 and v3. We do not know for certain if their
109 licenses are compatible with the LGPL.
110 If you wish to enable these libraries, pass `--enable-nonfree` to configure.
111 But note that if you enable any of these libraries the resulting binary will
112 be under a complex license mix that is more restrictive than the LGPL and that
113 may result in additional obligations. It is possible that these
114 restrictions cause the resulting binary to be unredistributeable.