diff options
Diffstat (limited to 'LICENSE.md')
| -rw-r--r-- | LICENSE.md | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/LICENSE.md b/LICENSE.md new file mode 100644 index 0000000000..ba65b059c5 --- /dev/null +++ b/LICENSE.md @@ -0,0 +1,120 @@ +# License + +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 +FFmpeg. + +Some optional parts of FFmpeg are licensed under the GNU General Public License +version 2 or later (GPL v2+). See the file `COPYING.GPLv2` for details. None of +these parts are used by default, you have to explicitly pass `--enable-gpl` to +configure to activate them. In this case, FFmpeg's license changes to GPL v2+. + +Specifically, the GPL parts of FFmpeg are: + +- libpostproc +- optional x86 optimization in the files + - `libavcodec/x86/flac_dsp_gpl.asm` + - `libavcodec/x86/idct_mmx.c` + - `libavfilter/x86/vf_removegrain.asm` +- the following building and testing tools + - `compat/solaris/make_sunver.pl` + - `doc/t2h.pm` + - `doc/texi2pod.pl` + - `libswresample/swresample-test.c` + - `tests/checkasm/*` + - `tests/tiny_ssim.c` +- the following filters in libavfilter: + - `vf_blackframe.c` + - `vf_boxblur.c` + - `vf_colormatrix.c` + - `vf_cover_rect.c` + - `vf_cropdetect.c` + - `vf_delogo.c` + - `vf_eq.c` + - `vf_find_rect.c` + - `vf_fspp.c` + - `vf_geq.c` + - `vf_histeq.c` + - `vf_hqdn3d.c` + - `vf_interlace.c` + - `vf_kerndeint.c` + - `vf_mcdeint.c` + - `vf_mpdecimate.c` + - `vf_owdenoise.c` + - `vf_perspective.c` + - `vf_phase.c` + - `vf_pp.c` + - `vf_pp7.c` + - `vf_pullup.c` + - `vf_repeatfields.c` + - `vf_sab.c` + - `vf_smartblur.c` + - `vf_spp.c` + - `vf_stereo3d.c` + - `vf_super2xsai.c` + - `vf_tinterlace.c` + - `vf_uspp.c` + - `vsrc_mptestsrc.c` + +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. + +There are a handful of files under other licensing terms, namely: + +* The files `libavcodec/jfdctfst.c`, `libavcodec/jfdctint_template.c` and + `libavcodec/jrevdct.c` are taken from libjpeg, see the top of the files for + licensing details. Specifically note that you must credit the IJG in the + documentation accompanying your program if you only distribute executables. + You must also indicate any changes including additions and deletions to + those three files in the documentation. +* `tests/reference.pnm` is under the expat license. + + +## External libraries + +FFmpeg can be combined with a number of external libraries, which sometimes +affect the licensing of binaries resulting from the combination. + +### Compatible libraries + +The following libraries are under GPL: +- frei0r +- libcdio +- librubberband +- libvidstab +- libx264 +- libx265 +- libxavs +- libxvid + +When combining them with FFmpeg, FFmpeg needs to be licensed as GPL as well by +passing `--enable-gpl` to configure. + +The OpenCORE and VisualOn 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 these libraries with FFmpeg, the +license version needs to be upgraded by passing `--enable-version3` to configure. + +### Incompatible libraries + +There are certain libraries you can combine with FFmpeg whose licenses are not +compatible with the GPL and/or the LGPL. If you wish to enable these +libraries, even in circumstances that their license may be incompatible, pass +`--enable-nonfree` to configure. But note that if you enable any of these +libraries the resulting binary will be under a complex license mix that is +more restrictive than the LGPL and that may result in additional obligations. +It is possible that these restrictions cause the resulting binary to be +unredistributable. + +The Fraunhofer FDK AAC and OpenSSL libraries are under licenses which are +incompatible with the GPLv2 and v3. To the best of our knowledge, they are +compatible with the LGPL. + +The NVENC library, while its header file is licensed under the compatible MIT +license, requires a proprietary binary blob at run time, and is deemed to be +incompatible with the GPL. We are not certain if it is compatible with the +LGPL, but we require `--enable-nonfree` even with LGPL configurations in case +it is not. |