OpenAL Soft

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OpenAL Soft is an LGPL-licensed, cross-platform, software implementation of the OpenAL 3D audio API. It's forked from the open-sourced Windows version available originally from openal.org's SVN repository (now defunct). OpenAL provides capabilities for playing audio in a virtual 3D environment. Distance attenuation, doppler shift, and directional sound emitters are among the features handled by the API. More advanced effects, including air absorption, occlusion, and environmental reverb, are available through the EFX extension. It also facilitates streaming audio, multi-channel buffers, and audio capture.

More information is available on the official website.

License

The OpenAL Soft project is provided under the terms of the LGPL 2 or later (see COPYING).

The default HRTF dataset is derived from the [SADIE II database[(https://www.york.ac.uk/sadie-project/database.html), and is provided under the Apache 2.0 license (see LICENSE.Apache-2.0.txt).

Source Install

To install OpenAL Soft, use your favorite shell to go into the build/ directory, and run:

cmake ..

Alternatively, you can use any available CMake front-end, like cmake-gui, ccmake, or your preferred IDE's CMake project parser.

Assuming configuration went well, you can then build it. The command cmake --build . will instruct CMake to build the project with the toolchain chosen during configuration (often GNU Make or NMake, although others are possible).

Please Note: Double check that the appropriate backends were detected. Often, complaints of no sound, crashing, and missing devices can be solved by making sure the correct backends are being used. CMake's output will identify which backends were enabled.

For most systems, you will likely want to make sure PipeWire, PulseAudio, and ALSA were detected (if your target system uses them). For Windows, make sure WASAPI was detected.

Building openal-soft - Using vcpkg

You can download and install openal-soft using the vcpkg dependency manager:

git clone https://github.com/Microsoft/vcpkg.git
cd vcpkg
./bootstrap-vcpkg.sh
./vcpkg integrate install
./vcpkg install openal-soft

The openal-soft port in vcpkg is kept up to date by Microsoft team members and community contributors. If the version is out of date, please create an issue or pull request on the vcpkg repository.

Utilities

The source package comes with an informational utility, openal-info, and is built by default. It prints out information provided by the ALC and AL sub- systems, including discovered devices, version information, and extensions.

Configuration

OpenAL Soft can be configured on a per-user and per-system basis. This allows users and sysadmins to control information provided to applications, as well as application-agnostic behavior of the library. See alsoftrc.sample for available settings.

Language Bindings

As a C API, OpenAL Soft can be used directly by any language that can use functions with C linkage. For languages that can't directly use C-style headers, bindings may be developed to allow code written in that language to call into the library. Some bindings for some languages are listed here.

C# Bindings:

• OpenTK includes low-level C# bindings for the OpenAL API, including some extensions. It also includes utility libraries for math and linear algebra, which can be useful for 3D calculations.

Java Bindings:

• LWJGL, the Lightweight Java Game Library, includes Java bindings for the OpenAL API, usable with OpenAL Soft.
• JOAL, part of the JogAmp project, includes Java bindings for the OpenAL API, usable with OpenAL Soft. It also includes a higher level Sound3D Toolkit API and utility functions to make easier use of OpenAL features and capabilities.

Kotlin Bindings:

• Multiplatform OpenAL, developed for the Kleaver project, includes Kotlin/Native bindings for the OpenAL API, based on OpenAL Soft with support for Windows, Linux, macOS, iOS and Android.

Python Bindings:

• PyOpenAL. Also includes methods to play wave files and, with PyOgg, also Vorbis, Opus, and FLAC.

FreePascal/Lazarus Bindings:

• ALSound. Also includes a higher level API and libsndfile support to simplify loading and playing sounds.

Other bindings for these and other languages also exist. This list will grow as more bindings are found.

Acknowledgements

Special thanks go to:

• Creative Labs for the original source code this is based off of.
• Christopher Fitzgerald for the current reverb effect implementation, and helping with the low-pass and HRTF filters.
• Christian Borss for the 3D panning code previous versions used as a base.
• Ben Davis for the idea behind a previous version of the click-removal code.
• Richard Furse for helping with my understanding of Ambisonics that is used by the various parts of the library.