Clarify that our LGPL/GPL licenses come with an explicit "or later" clause.
[libav.git] / README
1 FFmpeg README
2 -------------
3
4 1) Documentation
5 ----------------
6
7 * Read the documentation in the doc/ directory.
8
9 2) Licensing
10 ------------
11
12 * Read the file COPYING.LGPL. FFmpeg and the associated libraries EXCEPT
13 for libpostproc are licensed under the GNU Lesser General Public License
14 version 2.1 or later.
15
16 * libpostproc is distributed under the GNU General Public License version 2
17 or later, see the file COPYING.GPL for details. Its compilation and use in
18 FFmpeg is optional.
19
20 * libswscale contains some optional processor-specific optimizations that are
21 distributed under the GNU General Public License version 2 or later.
22
23 * The files libavcodec/x86/idct_mmx.c, libavcodec/x86/h264_deblock_sse2.asm
24 and libavcodec/x86/h264_idct_sse2.asm are distributed under the GNU General
25 Public License version 2 or later. They are strictly optimizations and
26 their use is optional.
27
28 * The file libavcodec/ac3dec.c is distributed under the GNU General Public
29 License version 2 or later. In order for (E-)AC-3 decoding to work you
30 need to enable GPL components.
31
32 * The file libavdevice/x11grab.c is distributed under the GNU General
33 Public License version 2 or later. X11 grabbing is optional.
34
35 * The files libavcodec/jfdctfst.c, libavcodec/jfdctint.c, libavcodec/jrevdct.c
36 are taken from libjpeg, see the top of the files for licensing details.
37
38 * The file libavcodec/fdctref.c is copyrighted by the MPEG Software Simulation
39 Group with all rights reserved. It is only used to create a DCT test program
40 and not compiled into libavcodec.
41
42 * Some external libraries are under GPL. If you wish to use them with FFmpeg,
43 you have to configure FFmpeg as GPL as well.