ofxSteamAudio

Physics-based 3D audio for openFrameworks — Steam Audio 4.8.1 (Phonon C API)

RAII C++ wrappers covering the public Steam Audio C API, plus interactive examples that mirror Valve’s integration tests (core/src/itest).

Features

Area	Wrapper types	Steam Audio itest
Context / memory	Context	memory, log
Audio buffers	AudioBuffer	AudioBuffer
HRTF	HRTF	HRTFDatabase
Binaural	BinauralEffect	binauraleffect
Panning	PanningEffect	panningeffect
Virtual surround	VirtualSurroundEffect	virtualsurroundeffect
Ambisonics	Encode / Panning / Binaural / Rotation / Decode	ambisonics*
Direct path	DirectEffect + Simulator	directsoundeffect, directsimulator
Reflections	ReflectionEffect, ReflectionMixer	parametricreverb, reverbeffect, convolutioneffect
Pathing	PathEffect, probes, bakers	pathing, probes
Scene	Scene, static / instanced mesh	scene, staticmesh, instancedmesh
Energy / IR	EnergyField, ImpulseResponse, Reconstructor	energyfield, impulseresponse
High-level	Engine	multi-source binaural demo

Also wraps: serialization, Embree device (x86_64), distance attenuation, air absorption, directivity, relative direction.

Layout

src/                    # wrappers (include ofxSteamAudio.h)
libs/steamaudio/        # headers + prebuilt libphonon (+ mysofa, pffft)
examples/
  simple-example/           # Binaural HRTF multi-source
  example-panning/          # Stereo panning
  example-ambisonics/       # Ambisonics encode → binaural
  example-virtual-surround/ # 5.1 → binaural
  example-direct/           # Occlusion + direct effect
  example-scene/            # Static + instanced meshes
  example-reflections/      # Parametric reverb
  example-pathing/          # Probe generation + path scaffolding
tests/api-tests/            # Headless coverage of all wrappers
.github/workflows/macos.yml # CI: macOS build + run tests

Quick start

#include "ofxSteamAudio.h"

ofxSteamAudio::Engine audio;

void setup() {
    audio.setup(44100, 512);
    int id = audio.addSource(glm::vec3(2, 0, 0));
    audio.setSourceFrequency(id, 220.0f);

    ofSoundStreamSettings s;
    s.numOutputChannels = 2;
    s.sampleRate = 44100;
    s.bufferSize = 512;
    s.setOutListener(this);
    soundStream.setup(s);
}

void update() {
    audio.setListener(cam);
    audio.updateSource(0, sourceWorldPos);
}

void audioOut(ofSoundBuffer& buffer) {
    audio.processAudio(buffer); // synthesizes tones + binaural spatialize
}

Low-level API (full control):

ofxSteamAudio::Context ctx;
ofxSteamAudio::HRTF hrtf;
ofxSteamAudio::BinauralEffect binaural;
// ctx.setup(); hrtf.create(ctx, audioSettings); binaural.create(ctx, audioSettings, hrtf);
// binaural.apply(direction, hrtf, monoIn.get(), stereoOut.get());

Building

Requires openFrameworks (tested with modern OF on macOS arm64/x86_64).

1. Get Steam Audio binaries

Prebuilt libs are not committed to git. Use the library manager:

./scripts/manage_libs.sh

Menu	Who	What
1 Download from release tag	Consumers	Pull libs-v4.8.1 assets (default install)
2 Build with apothecary	Maintainers	Standalone apothecary only (no full OF)
3 Package	Maintainers	Write scripts/dist/steamaudio-*.tar.gz
4 Upload	Maintainers	gh release upload to tag libs-v*
5 Build + package + upload	Maintainers	Full local pipeline for one platform

Non-interactive:

./scripts/download_libs.sh host          # this machine
./scripts/download_libs.sh osx
./scripts/build_libs.sh osx              # clones openframeworks/apothecary if needed
./scripts/package_libs.sh osx
./scripts/manage_libs.sh upload libs-v4.8.1
./scripts/manage_libs.sh list            # full platform matrix
./scripts/manage_libs.sh status

build_libs.sh does not need openFrameworks — only openframeworks/apothecary (APOTHECARY_DIR / auto-cache).

Platforms (OF ∩ Steam Audio + OF extras): osx, linux64, linuxaarch64, vs-x64, ios, android-*, emscripten-*, plus experimental/planned rows — see scripts/platforms.sh.

2. Build examples / tests

cd examples/simple-example && make -j
cd tests/api-tests && make -j Release && make RunRelease

Link notes (macOS)

addon_config.mk pulls libphonon (+ libmysofa / libpffft when present), zlib, Accelerate, AudioToolbox, CoreAudio. Default ray tracer (no Embree) works on Apple Silicon.

Platform tracking & releases

Live matrix: PLATFORM_STATUS.md (regenerated by CI / scripts).

./scripts/manage_libs.sh list          # platforms + GHA runners
./scripts/manage_libs.sh report        # local + release probe → PLATFORM_STATUS.md
./scripts/test_package.sh osx          # layout test (no OF)

Workflow	OF?	Purpose
CI	No	Probe every release asset; download+test those present; write status (failures tracked, missing = warning)
CI optional OF job	Yes	Dispatch with run_of_tests=true
Build Steam Audio libs	No — apothecary only	Build all CI-mapped platforms (continue-on-error); package successes; aggregate PLATFORM_STATUS.md; optional upload to libs-v*

Maintainer release loop:

1. Actions → Build Steam Audio libs (apothecary) → Run
   • upload_release: true, libs_tag: libs-v4.8.1
   • Filter: all / full / experimental
2. Job matrix includes osx, linux64, linuxaarch64, vs-, ios, android-, emscripten-, tvos, planned Apple, etc.
3. Failures are OK — each platform writes status JSON; report job merges into PLATFORM_STATUS.md
4. Only successful .tar.gz files are uploaded to the release
5. CI then tracks which assets exist / pass package tests

Asset name: steamaudio-4.8.1-<package_id>.tar.gz

Steam Audio

• Steam Audio GitHub
• C API docs
• Version: 4.8.1 (STEAMAUDIO_VERSION from phonon_version.h)

License

Addon code: see LICENSE. Steam Audio: Apache 2.0 — see libs/steamaudio/license/.