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:
libavcodec/x86/flac_dsp_gpl.asm
libavcodec/x86/idct_mmx.c
libavfilter/x86/vf_removegrain.asm
libavdevice/x11grab.c
compat/solaris/make_sunver.pl
doc/t2h.pm
doc/texi2pod.pl
libswresample/swresample-test.c
tests/checkasm/*
tests/tiny_ssim.c
f_ebur128.c
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:
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.FFmpeg can be combined with a number of external libraries, which sometimes affect the licensing of binaries resulting from the combination.
The following libraries are under GPL:
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.
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.