Resonance Audio abandoned

Microsoft Spatializer

Unity

A cross-platform spatializer plugin that integrates spatial audio processing into Unity projects. The plugin uses efficient DSP algorithms to render head-related transfer functions (HRTF) for immersive 3D audio positioning. Designed to fit Unity's audio engine architecture, it supports both Windows and Android platforms. Version 2.0 represents a complete rewrite focused on performance optimization and cross-platform compatibility. The plugin uses a multi-source mixer architecture that reduces CPU overhead compared to previous implementations. While an older HoloLens 2-specific version (v1) offered hardware DSP offload, the current version prioritizes flexibility and integration with Unity's audio pipeline. Note: the GitHub repository was archived (made read-only) in July 2024 and is no longer actively developed, though it remains usable for existing projects. It enables realistic directional audio cues essential for VR, AR, and immersive gaming experiences.

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.

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.

SPARTA

Standalone

SPARTA is a suite of open-source spatial audio plug-ins built on the Spatial Audio Framework. The collection provides comprehensive tools for Ambisonic encoding, decoding, rotation, and analysis, as well as specialized processors for beamforming, binaural rendering, room simulation, and sound-field visualization. Each plug-in supports high-order operations (up to 10th order Ambisonics) and many include SOFA file loading for HRIR/BRIR data and OSC head-tracking integration. The suite covers the full spatial audio pipeline: Array2SH encodes microphone arrays to Ambisonics, AmbiENC provides source panning, AmbiRoomSim adds image-source reflections, and AmbiDEC/AmbiBIN decode to loudspeakers or headphones. Analysis tools like PowerMap, DirASS, and SLDoA visualize directional sound-field characteristics. Additional utilities include dynamic range compression (AmbiDRC), arbitrary spreading (Spreader), VBAP panning, and matrix/multi-channel convolution with partitioned modes. All plug-ins are available as VST, VST3, AU, LV2, and AAX formats for macOS, Linux (x86_64 and ARM), and Windows. The codebase is built with JUCE and distributed under GPLv3, making it suitable for research, production, and custom extensions.