# 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.


********************************************************************************

libavformat/oggparsespeex.c

Copyright (C) 2008  Reimar Döffinger

      Permission is hereby granted, free of charge, to any person
      obtaining a copy of this software and associated documentation
      files (the "Software"), to deal in the Software without
      restriction, including without limitation the rights to use, copy,
      modify, merge, publish, distribute, sublicense, and/or sell copies
      of the Software, and to permit persons to whom the Software is
      furnished to do so, subject to the following conditions:

      The above copyright notice and this permission notice shall be
      included in all copies or substantial portions of the Software.

      THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
      EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
      MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
      NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
      HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
      WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
      OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
      DEALINGS IN THE SOFTWARE.

********************************************************************************

libavformat/oggparsetheora.c

Copyright (C) 2005  Matthieu CASTET, Alex Beregszaszi

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use, copy,
modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.

********************************************************************************

libswresample/swresample.h

Copyright (C) 2011-2013 Michael Niedermayer (michaelni@gmx.at)

This file is part of libswresample

libswresample is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

libswresample is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with libswresample; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

********************************************************************************

libswresample/version.h

Version macros.

This file is part of libswresample

libswresample is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

libswresample is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with libswresample; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

********************************************************************************

libavcodec/x86/xvididct.asm

XVID MPEG-4 VIDEO CODEC

 Conversion from gcc syntax to x264asm syntax with modifications
 by Christophe Gisquet <christophe.gisquet@gmail.com>

 ===========     SSE2 inverse discrete cosine transform     ===========

 Copyright(C) 2003 Pascal Massimino <skal@planet-d.net>

 Conversion to gcc syntax with modifications
 by Alexander Strange <astrange@ithinksw.com>

 Originally from dct/x86_asm/fdct_sse2_skal.asm in Xvid.

 Vertical pass is an implementation of the scheme:
  Loeffler C., Ligtenberg A., and Moschytz C.S.:
  Practical Fast 1D DCT Algorithm with Eleven Multiplications,
  Proc. ICASSP 1989, 988-991.

 Horizontal pass is a double 4x4 vector/matrix multiplication,
 (see also Intel's Application Note 922:
  http://developer.intel.com/vtune/cbts/strmsimd/922down.htm
  Copyright (C) 1999 Intel Corporation)

 More details at http://skal.planet-d.net/coding/dct.html

 =======     MMX and XMM forward discrete cosine transform     =======

 Copyright(C) 2001 Peter Ross <pross@xvid.org>

 Originally provided by Intel at AP-922
 http://developer.intel.com/vtune/cbts/strmsimd/922down.htm
 (See more app notes at http://developer.intel.com/vtune/cbts/strmsimd/appnotes.htm)
 but in a limited edition.
 New macro implements a column part for precise iDCT
 The routine precision now satisfies IEEE standard 1180-1990.

 Copyright(C) 2000-2001 Peter Gubanov <peter@elecard.net.ru>
 Rounding trick Copyright(C) 2000 Michel Lespinasse <walken@zoy.org>

 http://www.elecard.com/peter/idct.html
 http://www.linuxvideo.org/mpeg2dec/

 These examples contain code fragments for first stage iDCT 8x8
 (for rows) and first stage DCT 8x8 (for columns)

 conversion to gcc syntax by Michael Niedermayer

 ======================================================================

 This file is part of FFmpeg.

 FFmpeg is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 of the License, or (at your option) any later version.

 FFmpeg is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public License
 along with FFmpeg; if not, write to the Free Software Foundation,
 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

********************************************************************************

libavcodec/jfdctfst.c
libavcodec/jfdctint_template.c
libavcodec/jrevdct.c

This file is part of the Independent JPEG Group's software.

The authors make NO WARRANTY or representation, either express or implied,
with respect to this software, its quality, accuracy, merchantability, or
fitness for a particular purpose.  This software is provided "AS IS", and
you, its user, assume the entire risk as to its quality and accuracy.

This software is copyright (C) 1994-1996, Thomas G. Lane.
All Rights Reserved except as specified below.

Permission is hereby granted to use, copy, modify, and distribute this
software (or portions thereof) for any purpose, without fee, subject to
these conditions:
(1) If any part of the source code for this software is distributed, then
this README file must be included, with this copyright and no-warranty
notice unaltered; and any additions, deletions, or changes to the original
files must be clearly indicated in accompanying documentation.
(2) If only executable code is distributed, then the accompanying
documentation must state that "this software is based in part on the work
of the Independent JPEG Group".
(3) Permission for use of this software is granted only if the user accepts
full responsibility for any undesirable consequences; the authors accept
NO LIABILITY for damages of any kind.

These conditions apply to any software derived from or based on the IJG
code, not just to the unmodified library.  If you use our work, you ought
to acknowledge us.

Permission is NOT granted for the use of any IJG author's name or company
name in advertising or publicity relating to this software or products
derived from it.  This software may be referred to only as "the Independent
JPEG Group's software".

We specifically permit and encourage the use of this software as the basis
of commercial products, provided that all warranty or liability claims are
assumed by the product vendor.

********************************************************************************

libavcodec/fft_fixed_32.c
libavcodec/fft_init_table.c
libavcodec/fft_table.h
libavcodec/mdct_fixed_32.c
libavcodec/mips/aacdec_mips.h
libavcodec/mips/aacsbr_mips.h
libavcodec/mips/amrwbdec_mips.h
libavcodec/mips/compute_antialias_fixed.h
libavcodec/mips/compute_antialias_float.h
libavcodec/mips/lsp_mips.h
libavutil/fixed_dsp.c
libavutil/fixed_dsp.h
libavutil/mips/libm_mips.h
libavutil/softfloat_tables.h

Copyright (c) 2012
MIPS Technologies, Inc., California.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. Neither the name of the MIPS Technologies, Inc., nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE MIPS TECHNOLOGIES, INC. ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL THE MIPS TECHNOLOGIES, INC. BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.

Authors:
Branimir Vasic   (bvasic@mips.com)
Darko Laus       (darko@mips.com)
Djordje Pesut    (djordje@mips.com)
Goran Cordasic   (goran@mips.com)
Nedeljko Babic   (nedeljko.babic imgtec com)
Mirjana Vulin    (mvulin@mips.com)
Stanislav Ocovaj (socovaj@mips.com)
Zoran Lukic      (zoranl@mips.com)

********************************************************************************

libavformat/oggdec.c
libavformat/oggdec.h
libavformat/oggparseogm.c
libavformat/oggparsevorbis.c

Copyright (C) 2005  Michael Ahlberg, MÃ¥ns RullgÃ¥rd

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use, copy,
modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.

********************************************************************************

                  GNU LESSER GENERAL PUBLIC LICENSE
                       Version 2.1, February 1999

 Copyright (C) 1991, 1999 Free Software Foundation, Inc.
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 Everyone is permitted to copy and distribute verbatim copies
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           How to Apply These Terms to Your New Libraries

  If you develop a new library, and you want it to be of the greatest
possible use to the public, we recommend making it free software that
everyone can redistribute and change.  You can do so by permitting
redistribution under these terms (or, alternatively, under the terms of the
ordinary General Public License).

  To apply these terms, attach the following notices to the library.  It is
safest to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least the
"copyright" line and a pointer to where the full notice is found.

    <one line to give the library's name and a brief idea of what it does.>
    Copyright (C) <year>  <name of author>

    This library is free software; you can redistribute it and/or
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    This library is distributed in the hope that it will be useful,
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Also add information on how to contact you by electronic and paper mail.

You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the library, if
necessary.  Here is a sample; alter the names:

  Yoyodyne, Inc., hereby disclaims all copyright interest in the
  library `Frob' (a library for tweaking knobs) written by James Random Hacker.

  <signature of Ty Coon>, 1 April 1990
  Ty Coon, President of Vice

That's all there is to it!