Microsoft Spatializer abandoned

Resonance Audio

Unity · Wwise · FMOD · Standalone

Resonance Audio is a spatial audio SDK that provides HRTF-based binaural rendering, ambisonic encoding/decoding, and room modeling. Originally developed by Google and released as open source, it offers cross-platform support with integrations for Unity, Wwise, FMOD, and VST. The SDK includes tools for geometrical acoustics simulation, reverberation estimation from game geometry, and ambisonic soundfield capture. It supports first-order and higher-order ambisonics, room effects modeling, and binaural rendering using the SADIE HRTF database. The codebase is written in C++ and provides bindings for multiple platforms including desktop, mobile (Android/iOS), and various audio middleware systems. Note: Google archived the GitHub repository in November 2023, so it is no longer actively maintained, though all source code, build scripts, and platform integrations remain available under an open source license.

libmysofa

Standalone

libmysofa is a C library for reading and processing Head-Related Transfer Function (HRTF) data stored in AES SOFA files conforming to the AES69-2015 standard. It provides functions to load SOFA files, extract HRTF filters for specific spatial coordinates, and convert between Cartesian and spherical coordinate systems. The library handles automatic normalization of HRTF data, nearest-neighbor interpolation for arbitrary listener positions, and efficient caching of multiple SOFA files. It supports both integer and floating-point filter extraction with configurable sample rates and neighbor search parameters. Designed for integration into spatial audio engines and renderers, libmysofa offers both simple and advanced APIs for developers who need direct access to HRTF data without implementing SOFA parsing from scratch.

Steam Audio

Wwise · FMOD · Unity · Unreal

Spatial audio SDK from Valve. Provides geometric acoustics (ray-traced occlusion, early reflections, late reverb) and HRTF-based binaural rendering with a single core library plus first-party integrations for the four main game engines and middlewares. The core is C++ under the hood. You can either link it directly or drop in the Unity / Unreal / FMOD / Wwise integration packages and configure spatializers from each tool's authoring UI. Windows (32/64), Linux (32/64), macOS, Android (armv7/arm64/x86/x64), and iOS.

Omnitone

Standalone

Omnitone is a Web Audio API implementation of ambisonic decoding and binaural rendering. It supports first-order (4-channel) and higher-order ambisonic streams (2nd and 3rd order, up to 16 channels). The library uses native Web Audio nodes for performance-critical processing, ensuring efficient CPU usage. The implementation follows the Google spatial media specification and uses SADIE binaural filters for rendering. It accepts input from HTML media elements or multichannel AudioBufferSourceNodes, with support for dynamic rotation matrices to orient the sound field in response to user interaction or sensor data. Omnitone powers the Resonance Audio SDK for web and provides both ambisonic and bypass rendering modes. The library is designed for browser-based spatial audio applications, VR experiences, and 360-degree video playback. Note: the last release (v1.3.0) was in January 2019, so the project is effectively dormant.