godot4-opus/3rdparty/opus/license.txt

License
Opus has a freely available specification, a BSD-licensed, high-quality reference encoder and decoder, and protective, royalty-free licenses for the required patents. The copyright and patent licenses for Opus are automatically granted to everyone and do not require application or approval. The Opus FAQ has more information on why Opus is freely licensed.

In brief:(see below for details)

You can encode or decode Opus-compatible streams for any purpose at no cost.
You can integrate the reference Opus encoder and decoder in any application, program or product, even commercially, at no cost.
You can create your own compatible implementations of the Opus specification and give them away or sell them.
You may not do these things if you engage on Opus-related patent litigation against any user of Opus.
Licensing details
Copyright
Specification
The specification is freely available as part of IETF RFC 6716. The RFC includes the reference implementation, which is available under the three-clause BSD license (see below).

Implementation
Both the reference implementation and the revised implementations on opus-codec.org are available under the three-clause BSD license. This BSD license is compatible with all common open source and commercial software licenses.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

- Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

- 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.

- Neither the name of Internet Society, IETF or IETF Trust, nor the names of specific contributors, may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``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 COPYRIGHT OWNER OR CONTRIBUTORS 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.

Tools
Most of the command-line Ogg-based tools that are shipped as part of the separate opus-tools package are also released under the three-clause BSD license. The only exception is the opusinfo tool, which is released under the GPLv2 license. Proprietary software developers wishing to use Opus may copy code from opusenc and opusdec, but they may not copy code from the opusinfo tool to build their applications.

Patents
Opus is covered by several patents. These patents are available under open-source-compatible, royalty-free licenses. If you are not trying to attack Opus with your patents, you will not have problems with these licenses.

Some of these licenses have been updated in the past and may be updated again in the future. However, updates never invalidate the old licenses and users are always free to rely on any of the previously available licenses. In other words, newer licenses can give more rights, but never fewer.

Xiph.Org Foundation
The Xiph.Org foundation has several patent applications on techniques used in Opus. When issued, these patents will be automatically available under the terms provided in the below license. The license covers the listed patent applications, along with any other patent or application covering Opus that is owned by Xiph.Org.

Xiph.Org Patents/Applications covered:

US 61/284,154
US 61/450,041
US 61/450,053
US 61/450,060
and any other applicable
LICENSE GRANT
Xiph.Org Foundation (“Xiph”) hereby grants to you a perpetual, worldwide, non-exclusive, no-charge,royalty-free, irrevocable (except as stated in this license) license under Licensed Patents to make, have made, use, offer to sell, sell, import, transfer, and otherwise run, modify (in a way that still complies with the Specification), and reproduce any Implementation.

Definitions. Specification means, and includes the following, both individually and collectively, (a) any standard specification of the Opus codec adopted by the IETF Codec Working Group (“Standard”) and (b) any reference implementation (each, a “Reference Implementation”) published by the IETF Codec Working Group in the request for comments (“RFC”) issued by the IETF for the Specification draft for which this License is issued, or any RFC that is issued as an update or new version thereof. An Implementation means any Reference Implementation, or another implementation that complies with the Specification. Licensed Patents means all patents currently owned by Xiph or acquired hereafter that Xiph has the right to license as set forth above and that are necessarily infringed by the Specification, where “necessarily infringed” means: in the case of (a) above, there is no commercially viable means of implementing the Specification without infringing such patent; in the case of (b) above, use of the reference implementation to the extent it infringes such patent.

Termination. If you, directly or indirectly via controlled affiliate or subsidiary, agent, or exclusive licensee, file a Claim for patent infringement against any entity alleging that an Implementation in whole or in part constitutes direct or contributory patent infringement, or inducement of patent infringement (a “Claim”), provided that a Reference Implementation also infringes the patents asserted in the Claim, then any patent rights granted to you under this License shall automatically terminate retroactively as of the date you first received the grant. Claims made against an Implementation in part will only trigger termination if the Implementation in part was done for the purpose of combining it with other technology that complies with the Specification so that the technology’s ultimate use will be consistent with the Standard as a whole.

This license is also filed on the IETF site.

Broadcom
Broadcom has both issued patents and outstanding applications covering Opus. These are available under the same license as the Xiph.Org patents. The license covers the listed patents and patent applications, along with any other patent or application covering Opus that is owned by Broadcom.

Broadcom Patents/Applications covered:

US 61/406,106
US 61/394,842
US 7,353,168
and any other applicable
LICENSE GRANT
Broadcom Corporation (“Broadcom”) hereby grants to you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this license) license under Licensed Patents to make, have made, use, offer to sell, sell, import, transfer, and otherwise run, modify (in a way that still complies with the Specification), and reproduce any Implementation.

Definitions. Specification means, and includes the following, both individually and collectively, (a) any standard specification of the Opus codec adopted by the IETF Codec Working Group (“Standard”) and (b) any reference implementation (each, a “Reference Implementation”) published by the IETF Codec Working Group in the request for comments (“RFC”) issued by the IETF for the Specification draft for which this License is issued, or any RFC that is issued as an update or new version thereof. An Implementation means any Reference Implementation, or another implementation that complies with the Specification. Licensed Patents means all patents currently owned by Broadcom or acquired hereafter that Broadcom has the right to license as set forth above and that are necessarily infringed by the Specification, where “necessarily infringed” means: in the case of (a) above, there is no commercially viable means of implementing the Specification without infringing such patent; in the case of (b) above, use of the reference implementation to the extent it infringes such patent.

Termination. If you, directly or indirectly via controlled affiliate or subsidiary, agent, or exclusive licensee, file a Claim for patent infringement against any entity alleging that an Implementation in whole or in part constitutes direct or contributory patent infringement, or inducement of patent infringement (a “Claim”), provided that a Reference Implementation also infringes the patents asserted in the Claim, then any patent rights granted to you under this License shall automatically terminate retroactively as of the date you first received the grant. Claims made against an Implementation in part will only trigger termination if the Implementation in part was done for the purpose of combining it with other technology that complies with the Specification so that the technology’s ultimate use will be consistent with the Standard as a whole.

This license is also filed on the IETF site.

Microsoft
Microsoft acquired patents and applications related to Opus through their purchase of Skype. These patents (and any other Microsoft might have had) are available under a different, but still royalty-free, license detailed below. The license covers the listed patent applications, along with any other patent or application covering Opus that is owned by Microsoft.

Microsoft Patents/Applications covered:

US-2008-0201137-A1
US-2010-0174535-A1
US-2010-0174534-A1
US-2010-0174547-A1
US-2010-0174532-A1
US-2010-0174537-A1
US-2010-0174542-A1
US-2010-0174531-A1
US-2010-0174541-A1
US-2010-0174538-A1
US-2011-0077940-A1
and any other applicable
MICROSOFT OPUS PATENT TERMS
11-7-2012

1. Patent Terms.

1.1. Specification License. Subject to all the terms and conditions of this Agreement, I, on behalf of myself and my successors in interest and assigns, hereby grant you a non-sublicensable, perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable license to my Necessary Decoder Claims for your Specification Implementation.

1.2. Code License. Subject to all the terms and conditions of this Agreement, I, on behalf of myself and my successors in interest and assigns, hereby grant you a non-sublicensable, perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable patent license to my Necessary Reference Implementation Claims to make, use, sell, offer for sale, import or distribute a Code Implementation.

1.3. Conditions.

1.3.1. Availability. If you own or control Necessary Claims, the licenses set forth in Section 1 are subject to and will become effective starting on the date that you make a binding public irrevocable commitment to license, on reasonable and non-discriminatory royalty-free licensing terms 1) your Necessary Decoder Claims to all implementers for Specification Implementations, and 2) your Necessary Reference Implementation Claims to all implementers for Code Implementations, where the terms of this Agreement satisfy any reciprocity requirements in your reasonable and non-discriminatory royalty-free licensing terms. The promises set forth in Section 1 will remain in effect so long as you continue to make such claims available for Specification Implementations and Code Implementations under reasonable and non-discriminatory royalty-free licensing terms. In addition, as a condition of the licenses set forth in Section 1, you acknowledge and agree that you have not and will not knowingly take any action for the purpose of circumventing the conditions in this Section 1. Notwithstanding the foregoing, you are not required to make the commitments set forth in this Section 1.3.1 as a result of merely using a Specification Implementation or a Code Implementation as an end-user.

1.3.2. Additional Conditions. This license is directly from me to you and you acknowledge as a condition of benefiting from it that no rights from me are received from suppliers, distributors, or otherwise in connection with this license. This license is not an assurance (i) that any of my issued patent claims covers a Specification Implementation or Code Implementation or are enforceable or (ii) that a Specification Implementation or Code Implementation would not infringe intellectual property rights of any third party.

1.4. Termination. All rights, grants, and promises made by me to you under Section 1 are immediately terminated if you or your agent file, maintain, or voluntarily participate in a lawsuit against me or any person or entity asserting that a Specification Implementation infringes Necessary Decoder Claims or a Code Implementation infringes Necessary Reference Implementation Claims, unless that suit was in response to a corresponding suit regarding a Specification Implementation or Code Implementation first brought against you. In addition, all rights, grants, and promises made by me to you under Section 1 are terminated if you, your agent, or successor in interest seek to license Necessary Decoder Claims for Specification Implementations or Necessary Reference Implementations Claims for Code Implementations on a royalty-bearing basis, unless that royalty-bearing licensing activity is in addition to, and not in lieu of, reasonable and non-discriminatory royalty-free licensing terms for Necessary Decoder Claims for Specification Implementations or Necessary Reference Implementation Claims for Code Implementations. This Agreement may also be terminated, including back to the date of non-compliance, because of non-compliance with any other term or condition of this Agreement.

2. Patent License Commitment. On behalf of me and my successors in interest and assigns, I agree to offer alternative reasonable and non-discriminatory royalty-bearing licensing terms 1) to my Necessary Decoder Claims solely for your Specification Implementation and 2) to my Necessary Reference Implementations Claims solely for your Code Implementation.

3. Past Skype Declarations. You may, at your option, continue to rely on the terms set forth in Skype’s past declarations made to the IETF for the Opus Audio Codec, subject to the terms of those declarations and in lieu of the terms of this Agreement solely for the patents set forth in those declarations.

4. Good Faith Obligations. I agree that I have not and will not knowingly take any action for the purpose of circumventing my obligations under this Agreement. In addition, I will not 1) seek an injunction or exclusion order against a) Code Implementations for Necessary Reference Implementation Claims or b) Specification Implementations for Necessary Decoder Claims or 2) require that an implementer license its patents back to me, except for Necessary Reference Implementation Claims for Code Implementations and Necessary Decoder Claims for Specification Implementations. I will not transfer Necessary Reference Implementation Claims or Necessary Decoder Claims unless the transferee is subject to these obligations.

5. Disclaimers. I expressly disclaim any warranties (express, implied, or otherwise), including implied warranties of merchantability, non-infringement, fitness for a particular purpose, or title, related to the Specification or Reference Implementation. The entire risk as to implementing or otherwise using the Specification, Specification Implementation, or Code Implementation is assumed by the implementer and user. IN NO EVENT WILL ANY PARTY BE LIABLE TO ANY OTHER PARTY FOR LOST PROFITS OR ANY FORM OF INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES OF ANY CHARACTER FROM ANY CAUSES OF ACTION OF ANY KIND WITH RESPECT TO THIS AGREEMENT, WHETHER BASED ON BREACH OF CONTRACT, TORT (INCLUDING NEGLIGENCE), OR OTHERWISE, AND WHETHER OR NOT THE OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Nothing in this Agreement requires me to undertake a patent search.

6. Definitions.

6.1. Agreement. “Agreement” means this document, which sets forth the rights, grants, limitations, conditions, obligations, and disclaimers made available for the particular Specification.

6.2. Code Implementation. “Code Implementation” means making, using, selling, offering for sale, importing or distributing 1) the Reference Implementation, or 2) an implementation that, in the case of an encoder, produces a bitstream that can be decoded by a Specification Implementation solely to the extent it produces such a bitstream, and, in the case of decoder, is a Specification Implementation, where that Specification Implementation may also infringe Necessary Reference Implementation Claims.

6.3. Control. “Control” means direct or indirect control of more than 50% of the voting power to elect directors of that corporation, or for any other entity, the power to direct management of such entity.

6.4. I, Me, or My. “I,” “me,” or “my” refers to the party making this declaration, and any entity that I Control.

6.5. Necessary Claims. “Necessary Claims” means Necessary Decoder Claims and Necessary Reference Implementation Claims.

6.6. Necessary Decoder Claims. “Necessary Decoder Claims” are those patent claims that a party owns or controls, including those claims acquired after the date of this declaration, that are necessarily infringed by an implementation of the required portions (including the required elements of optional portions) of the decoder Specification that are described in detail and not merely referenced in the Specification.

6.7. Necessary Reference Implementation Claims. “Necessary Reference Implementation Claims” are those patent claims that a party owns or controls, including those claims acquired after the date of this declaration, that are necessarily infringed by the Reference Implementation. Necessary Reference Implementation Claims do not include claims that would be infringed only as a consequence of further modification of the Reference Implementation.

6.8. Reference Implementation. “Reference Implementation” means the implementation of the Opus encoder and/or decoder code extracted from Appendix A of the Specification.

6.9. Specification. “Specification” means IETF RFC 6716 dated September 2012.

6.10. Specification Implementation. “Specification Implementation” means making, using, selling, offering for sale, importing or distributing any conformant implementation of the decoder set forth in the Specification 1) only to the extent it implements the Specification and 2) so long as all required portions of the Specification are implemented. Specification Implementation also includes any implementation of a decoder included in subsequent versions of RFC 6716 1) only to the extent that it implements the decoder Specification, and 2) so long as all required portions of the decoder Specification are implemented.

6.11. You or Your. “You,” “you,” or “your” means any person or entity who exercises patent rights granted under this Agreement, and any person or entity you Control.

This license is also filed on the IETF site. The old license is still available.

Other disclosures
While Xiph.Org, Broadcom, and Microsoft filed IPR disclosures giving royalty-free licenses to their patents used in Opus, four companies that did not directly participate in the development of Opus, Qualcomm, Huawei, France Telecom, and Ericsson, filed IPR disclosures with potentially royalty-bearing terms. The IETF allows anyone (and their dog) to file an IPR disclosures if they think that their patents “covers or may ultimately cover” a standard. In fact, for any organization who can be said to have contributed in any (very loosely defined) way, these IPR statements are not just allowed, but required. It is thus safer for organisations to declare as much as they can. As an example, one can find similar non-free Qualcomm IPR statements on both SIP and SDP. To our advantage, however, the IETF IPR disclosure policies require companies to provide the actual patent numbers. This allows anyone to verify these claims for themselves, which is definitely a good thing.

When it comes to patents, it is difficult to say much without making lawyers nervous. However, we can say something quite direct: external counsel Dergosits & Noah has advised us that Opus can be implemented without the need to license the patents disclosed by Qualcomm, Huawei, France Telecom, or Ericsson. We can also say that Mozilla is confident enough in Opus to ship it to hundreds of millions of Firefox users. Similarly, Cisco and Google are also supporting Opus in some products. More companies are expected to do the same soon.

Mozilla invested significant legal resources into avoiding known patent thickets when designing Opus. Whenever possible, we used processes and methods that have been long known in the field and which are considered patent-free. In addition, we filed numerous patent applications on the new things we invented to help defend the Opus community. As a result, Opus is available on a royalty-free basis and can be deployed by anyone, including other open-source projects. Everyone knows this is an incredibly challenging legal environment to operate in, but we think we’ve succeeded.