Legal Notices

The Engine stands upon the labors of the open-source ecosystem. The licenses under which those labors are granted, and the obligations the Forge keeps under them, are gathered here.

The Forge

Vox Machina Audio — the publishing Forge behind the Vox Machina USB audio engine for Android. For correspondence, address: legal@voxmachina.audio.

The Marks

Vox Machina and Vox Machina Audio are marks of the Forge. Android is a mark of Google LLC. All other product names, logos, brands, and marks named upon these pages are property of their respective holders, and are named here for identification only — no endorsement is claimed, none implied.

FFmpeg — LGPL Notice

The Engine carries FFmpeg (ffmpeg.org) as its decoder for a wide field of containers and codecs.

FFmpeg is granted under the GNU Lesser General Public License (LGPL) version 2.1 or later. The Engine links to FFmpeg dynamically — by way of shared libraries (.so) — in honor of LGPL 2.1 Section 6(b).

Libraries borne

Build configuration

The FFmpeg the Engine carries is built decode-only, LGPL-clean:

FFmpeg version: 7.1 Build flags: --disable-gpl --disable-nonfree --disable-programs --disable-doc --disable-encoders --disable-muxers --disable-devices --disable-avdevice --disable-avfilter --disable-postproc --disable-bsfs --disable-autodetect --enable-shared --disable-static --enable-small

Source and relinking

FFmpeg source is borne at ffmpeg.org/download.html.

A listener wishing to relink the Engine against a modified or updated FFmpeg may do so by:

The full text of the LGPL 2.1 is borne at gnu.org/licenses/old-licenses/lgpl-2.1.html.

libFLAC — BSD 3-Clause Notice

The Engine carries libFLAC (xiph.org/flac) for the decoding of FLAC audio, by way of a dedicated JNI bridge.

libFLAC is granted under the BSD 3-Clause License.

Copyright (C) 2000-2009 Josh Coalson Copyright (C) 2011-2024 Xiph.Org Foundation 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 copyright holder 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 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 HOLDER 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.

Chromaprint — LGPL Notice

The Engine carries Chromaprint 1.5.1 (github.com/acoustid/chromaprint) for native acoustic fingerprinting — the naming of a recording by the shape of its sound — by way of a dedicated JNI bridge, in service of the optional Metadata & Artwork Enrichment described in the Privacy Policy.

Chromaprint is granted under the GNU Lesser General Public License (LGPL) version 2.1 or later. The Engine links to it dynamically, by way of a shared library (.so), in honor of LGPL 2.1 Section 6(b). A listener wishing to relink against a modified Chromaprint may draw its source from the address above, build it with the Android NDK, and replace the .so within the application's jniLibs/arm64-v8a/ directory. The full text of the LGPL 2.1 is borne at gnu.org/licenses/old-licenses/lgpl-2.1.html.

taglib — LGPL Notice

The Engine carries taglib 2.3.1 for the reading and writing of audio metadata tags — the capture of a track's tags, and the write-back of corrected metadata and cover art under the optional Rite of Enrichment — by way of a dedicated JNI bridge.

taglib is dual-granted under the GNU Lesser General Public License (LGPL) version 2.1 and the Mozilla Public License (MPL) version 1.1. The Engine elects the LGPL 2.1.

Unlike FFmpeg and Chromaprint — unmodified, and separately linked — taglib here is both modified (a one-file include-guard patch restoring the format-selection guards) and statically archived into a combined shared library alongside the Engine's own bridge. It is therefore not a separately replaceable .so, and its obligation is discharged under LGPL 2.1 Section 6(a): the complete corresponding source is published, and the Engine's object code is offered for relinking upon request.

Source and relinking

The complete corresponding source — upstream taglib v2.3.1, the Engine's patch, and the build recipe — is published at the Forge's public mirror: github.com/MagosVox/VoxMachinaPublic. The object code needed to relink the combined library against a modified taglib is available on request, at legal@voxmachina.audio.

The Engine compiles in only the tag formats it writes — MPEG/ID3, Vorbis/FLAC/Ogg/Opus, MP4, and APE/WavPack; RIFF/WAV, AIFF, DSD, ASF, tracker, Matroska, Shorten, and TrueAudio support is compiled out. Bundled among taglib's own files are fileref_ext.h and fileref_ext.cpp — a stream-constructible variant of taglib's own resolver, itself taglib-derived and carrying taglib's original LGPL 2.1 / MPL 1.1 license, treated identically under the elected LGPL 2.1. The design of that variant follows a technique credited below.

Kyant0 — Design Credit

The stream-based construction technique the metadata bridge follows is credited to Kyant0/taglib (github.com/Kyant0/taglib), a project granted under the Apache License 2.0. No Apache-licensed code from that project is compiled into the Engine — the only files drawn from it are taglib-derived and licensed under LGPL 2.1 / MPL 1.1, acknowledged in the taglib notice above. This credit is offered for the technique alone.

Apache-Granted Libraries

The Engine further rests upon a number of libraries granted under the Apache License, Version 2.0, each acknowledged with gratitude:

Copyright The Android Open Source Project / JetBrains s.r.o. / Square, Inc. / respective authors Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

AutoEQ Measurement Profiles — MIT Notice

The Engine's in-app GraphicEQ headphone-correction profiles are derived from the AutoEQ project (github.com/jaakkopasanen/AutoEq), granted under the MIT License. Profiles are sourced from community reviewers including oratory1990, Super Review, ToneDeafMonk, HypetheSonics, freeryder05, Innerfidelity, and the Headphone.com Legacy set, and packaged for distribution by timschneeb/AutoEqPackages. Commercial measurements (Rtings, crinacle) are not included.

MIT License Copyright (c) 2018 Jaakko Pasanen 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.

Singularity Ambient — Pixabay Content License

The photo-real Kerr black-hole accretion-disk loop used in the Singularity ambient is drawn from Pixabay (pixabay.com), rendered by Pixabay user “u_l0oiolyzfi”, and used ship-as-is under the Pixabay Content License.

PIXABAY CONTENT LICENSE 5. Content License granted to you for Content (other than CC0 Content). Subject to the Prohibited Uses described below (which you agree and acknowledge you are not entitled to engage in), when you download any Content that is not CC0 Content from the Service, we grant you an irrevocable, worldwide, perpetual (or as long as allowed by law), non-exclusive and royalty-free right to download, use, copy, modify or adapt the Content for commercial or non-commercial purposes ('Content License'). The rights granted are non-exclusive, meaning that we may also grant other users the same rights in the same Content. You agree and acknowledge that certain uses are "Prohibited Uses" and the Content License granted is conditional on you not engaging in any of them — including, in summary: selling or distributing the Content on a standalone basis; using Content depicting trademarks, logos or brands for commercial purposes; using Content in any immoral or illegal way; using Content in a misleading or deceptive way (including implying endorsement); or using Content as part of a trade-mark, design-mark, trade-name, business name or service mark. 6. Attribution. You do not need to credit Pixabay or the contributor of Content when you use it, but it is certainly appreciated when you do so. You can provide credit in the following format: "by [Contributor] via Pixabay". Full terms: https://pixabay.com/service/license-summary/

Glass Vigil Ambient — Pexels Free License

The 4K rain-on-glass loop used in the Glass Vigil ambient is drawn from Pexels (pexels.com), created by Phil Desforges, seamlessly looped with its audio stripped prior to use, under the Pexels Free License.

PEXELS FREE LICENSE What is allowed? All photos and videos on Pexels are free to use. Attribution is not required. Giving credit to the photographer or Pexels is not necessary but always appreciated. You can modify the photos and videos from Pexels. What is not allowed? Identifiable people may not appear in a bad light or in a way that is offensive. Don't sell unaltered copies of a photo or video. Don't imply endorsement of your product by people or brands on the imagery. Don't redistribute or sell the photos and videos on other stock photo or wallpaper platforms. Don't use the photos or videos as part of your trade-mark, design-mark, trade-name, business name or service mark. Full terms: https://www.pexels.com/license/

Data Sources of the Enrichment Rite

The optional Metadata & Artwork Enrichment described in the Privacy Policy draws upon three public data services. None is a bundled library; each governs its own data under its own terms, and no endorsement by any is claimed or implied.

MusicBrainz

MusicBrainz is an open music encyclopedia that collects music metadata and makes it available to the public. Core MusicBrainz data is released under the Creative Commons CC0 1.0 Universal Public Domain Dedication. MusicBrainz's own data usage guidelines request attribution for applications built on its data, and ask that use of the data not imply endorsement by the MusicBrainz project or the MetaBrainz Foundation. See https://musicbrainz.org/doc/About/Data_License for the current terms.

Cover Art Archive

The Cover Art Archive is a joint project between the MetaBrainz Foundation and the Internet Archive — images are hosted on Internet Archive infrastructure and served via a redirect from coverartarchive.org. Cover art images carry varying licenses set by their individual contributors — there is no single blanket license covering all images in the archive. Vox Machina assumes no particular license for a fetched image beyond respecting the rights its contributor has declared. See https://coverartarchive.org/ for the current terms.

AcoustID

AcoustID is an audio identification web service based on the Chromaprint acoustic fingerprinting library. Applications that query the service require a registered application API key and must comply with its usage terms. For identification, Vox Machina sends only a Chromaprint acoustic fingerprint of a track's audio (a compact hash, not the audio itself) together with the track's duration, and receives candidate MusicBrainz recording identifiers in return. Vox Machina also offers an optional contribution feature that calls AcoustID's /v2/submit endpoint, which permanently and publicly associates a fingerprint with a recording. It is disabled by default, requires a separate explicit opt-in, and any contribution is attributed to the listener's own AcoustID account — entered by the listener and stored only on their device — never the developer's. See https://acoustid.org/webservice for the current terms.

Of Warranty

The Engine is offered as it stands, without warranty of any kind, expressed or implied. The Forge shall not be held to answer for damages arising from the use, or the inability to use, the software, to the fullest extent allowed by law.

To Reach the Forge

For legal correspondence — including matters of copyright or marks — address the Forge: legal@voxmachina.audio.