r8brain-free-src — MIT, Aleksey Vaneev
High-Quality Audio Sample Rate Converter
Home: https://github.com/avaneev/r8brain-free-src
Used for: oversampling, FFT-backed cepstral min-phase synthesis (apodizer),
and FIR filter generation in HeadMania's DSP pipeline.
MIT License
Copyright (c) 2013-2025 Aleksey Vaneev
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.
PFFFT — BSD-style, Julien Pommier / NCAR FFTPACK
A Pretty Fast FFT
Home: https://bitbucket.org/jpommier/pffft
Used for: bundled FFT inside r8brain-free-src.
Derived from FFTPACKv4 (Paul Swarztrauber, NCAR, 1985) under FFTPACKv5 terms.
Copyright (c) 2013 Julien Pommier ( pommier@modartt.com )
Copyright (c) 2020 Hayati Ayguen ( h_ayguen@web.de )
Copyright (c) 2020 Dario Mambro ( dario.mambro@gmail.com )
Based on original fortran 77 code from FFTPACKv4 from NETLIB, authored by
Dr Paul Swarztrauber of NCAR, in 1985.
As confirmed by the NCAR fftpack software curators, the following FFTPACKv5
license applies to FFTPACKv4 sources. My changes are released under the same
terms.
FFTPACK license:
http://www.cisl.ucar.edu/css/software/fftpack5/ftpk.html
Copyright (c) 2004 the University Corporation for Atmospheric Research
("UCAR"). All rights reserved. Developed by NCAR's Computational and
Information Systems Laboratory, UCAR, www.cisl.ucar.edu.
Redistribution and use of the Software in source and binary forms, with or
without modification, is permitted provided that the following conditions
are met:
- Neither the names of NCAR's Computational and Information Systems
Laboratory, the University Corporation for Atmospheric Research, nor the
names of its sponsors or contributors may be used to endorse or promote
products derived from this Software without specific prior written
permission.
- Redistributions of source code must retain the above copyright notices,
this list of conditions, and the disclaimer below.
- Redistributions in binary form must reproduce the above copyright notice,
this list of conditions, and the disclaimer below in the documentation
and/or other materials provided with the distribution.
THIS 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
CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 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 WITH THE
SOFTWARE.
Ooura FFT — permissive, fee-free, Takuya Ooura
General Purpose FFT Package
Home: https://www.kurims.kyoto-u.ac.jp/~ooura/fft.html
Used for: the FP64 large-N FFT backend behind minimum-phase kernel synthesis
(core/src/apodizing_filter.cpp includes fft/fft4g.h directly, so this is
linked regardless of the PFFFT build option).
Copyright(C) 1996-2001 Takuya OOURA
The in-tree wrapper (third_party/r8brain-free-src/fft/fft4g.h) records the
grant as: "Modified and used with permission granted by the license."
The author's terms, from the package home page above:
You may use, copy, modify and distribute this code for any purpose (include
commercial use) and without fee. Please refer to this package when you
modify this code.
cpp-httplib — MIT, Yuji Hirose
Single-file C++ HTTP/HTTPS Server and Client Library
Home: https://github.com/yhirose/cpp-httplib
Used for: HTTP server (UI hosting, REST API) and UPnP HTTP transport.
MIT License
Copyright (c) 2025 Yuji Hirose. All rights reserved.
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.
dr_libs — Unlicense OR MIT-0, David Reid
Single-file Public-Domain Audio Decoders (dr_flac, dr_wav, dr_mp3)
Home: https://github.com/mackron/dr_libs
Used for: FLAC / WAV / MP3 decoding in the file-input audio path.
Dual-licensed: choose either alternative below.
This software is available as a choice of the following licenses. Choose
whichever you prefer.
═══════════════════════════════════════════════════════════════════════════════
ALTERNATIVE 1 - Public Domain (www.unlicense.org)
═══════════════════════════════════════════════════════════════════════════════
This is free and unencumbered software released into the public domain.
Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
software, either in source code form or as a compiled binary, for any purpose,
commercial or non-commercial, and by any means.
In jurisdictions that recognize copyright laws, the author or authors of this
software dedicate any and all copyright interest in the software to the public
domain. We make this dedication for the benefit of the public at large and to
the detriment of our heirs and successors. We intend this dedication to be an
overt act of relinquishment in perpetuity of all present and future rights to
this software under copyright law.
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 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.
For more information, please refer to <http://unlicense.org/>
═══════════════════════════════════════════════════════════════════════════════
ALTERNATIVE 2 - MIT No Attribution
═══════════════════════════════════════════════════════════════════════════════
Copyright 2020 David Reid
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.
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.
doctest — MIT, Viktor Kirilov
C++ Single-Header Test Framework
Home: https://github.com/doctest/doctest
Used for: HeadMania unit tests (hm_tests). NOT distributed in release
binaries — included here for completeness only.
The MIT License (MIT)
Copyright (c) 2016-2023 Viktor Kirilov
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.
═══════════════════════════════════════════════════════════════════════════════
NOTES FOR WINDOWS BUILDS
═══════════════════════════════════════════════════════════════════════════════
The Windows build of HeadMania UpSampler additionally redistributes the
Microsoft Edge WebView2 runtime loader (WebView2Loader.dll). The WebView2
SDK is distributed under Microsoft's own license; the LICENSE.txt and
NOTICE.txt files from the WebView2 SDK accompany the Windows release ZIP.
─────────────────────────────────────────────────────────────────────────────
Steinberg ASIO SDK 2.3.4
HeadMania UpSampler builds against the Steinberg ASIO SDK on Windows
to support generic ASIO output drivers including Diretta Host.
The SDK files themselves are NOT redistributed with HeadMania source.
Developers must download the SDK from https://www.steinberg.net/asiosdk
and configure CMake to find it (see docs/build-asio-setup.md).
ASIO is a trademark and software of Steinberg Media Technologies GmbH.
The compiled HeadMania binary is distributed under a signed
Steinberg ASIO Licensing Agreement.
─────────────────────────────────────────────────────────────────────────────
─────────────────────────────────────────────────────────────────────────────
ONNX Runtime (C/C++ API headers)
HeadMania UpSampler's experimental Neuromancer renderer compiles against the
ONNX Runtime C/C++ API headers on Windows (third_party/onnxruntime/include).
The runtime library itself is NOT redistributed with HeadMania: it is loaded
at run time from a path the listener configures, and the renderer reports
itself unavailable until one is present.
Home: https://github.com/microsoft/onnxruntime
MIT License
Copyright (c) Microsoft Corporation
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.
─────────────────────────────────────────────────────────────────────────────
═══════════════════════════════════════════════════════════════════════════════
END OF THIRD-PARTY LICENSES
═══════════════════════════════════════════════════════════════════════════════
AutoEq — data, credited, Jaakko Pasanen + measuring labs
Headphone Correction Data
Home: https://github.com/jaakkopasanen/AutoEq
Used for: the AutoEQ tab. The headphone list bundled with the app is built
from AutoEq's results index; each correction and measurement
graph is downloaded from the AutoEq repository when the listener
picks a headphone.
AutoEq is created and maintained by Jaakko Pasanen. HeadMania uses none of
AutoEq's code: it reads AutoEq's published correction files with its own parser
and applies them with its own filters. AutoEq's MIT licence covers its code;
the measurement data belongs to the labs and reviewers who made it.
The AutoEQ tab names the measuring lab on every headphone entry and under every
graph. In the bundled list, measurements come from crinacle, Innerfidelity,
Super Review, Rtings, oratory1990, ToneDeafMonk, Jaytiss, Headphone.com
(legacy), Hi End Portable, Kuulokenurkka, HypetheSonics, RikudouGoku, Regan
Cipher, Harpo, Filk, Fahryst, kr0mka, Kazi, DHRME, Auriculares Argentina,
freeryder05, Bakkwatan and Ted's Squig Hoard.
The AutoEQ feature is free for every user on every platform. Listing AutoEq
here does not imply that its maintainer or any lab endorses this app.