stride3d/stride · error · Exception

VideoInstance AVFoundation failed to get the AudioEngine

Error message

VideoInstance AVFoundation failed to get the AudioEngine

What it means

While setting up audio for an AVFoundation-backed video instance, the code could not resolve an IAudioEngineProvider (or its AudioEngine) from Instance.Services, so no audio engine exists to register the audio stream with. The library throws rather than silently playing video without audio.

Solutions

1. Register IAudioEngineProvider (and ensure the audio engine is created) in the game's service registry before initializing video
2. Ensure the Stride audio system is initialized prior to video playback
3. If audio is unwanted, set VideoComponent.PlayAudio = false so the path is skipped
4. Check initialization order in Game onStart so audio precedes VideoComponent usage

Example fix

// before
var engine = Instance.Services.GetService<IAudioEngineProvider>()?.AudioEngine
    ?? throw new Exception("...");
// after
// in startup, before video init:
services.AddAudio(); // or manually register IAudioEngineProvider
var engine = Instance.Services.GetService<IAudioEngineProvider>()?.AudioEngine
    ?? throw new Exception("...");

var provider = Instance.Services.GetService<IAudioEngineProvider>();
bool audioReady = provider?.AudioEngine != null;
if (!audioReady) Instance.VideoComponent.PlayAudio = false; // or register audio first

bool AudioAvailable(SceneInstance s) => s.Services.GetService<IAudioEngineProvider>()?.AudioEngine != null;

try { backend.Initialize(url, start, len); }
catch (Exception ex) when (ex.Message.Contains("failed to get the AudioEngine"))
{ /* disable PlayAudio or initialize audio system and retry */ }

When it happens

Trigger: IAudioEngineProvider not registered in the service registry (Services.GetService returned null); audio engine not yet created/initialized when the video initializes; PlayAudio enabled and video has audio but the audio system was never set up.

Common situations: Running with a minimal/custom service registry missing Stride's audio module; console/platform builds where audio was intentionally stripped; initializing video before the audio engine in startup order.

Understand the failure class

Background: "not installed", "pip install", "required for": how missing-dependency errors surface across open-source libraries — this error's family across 34 libraries.

Related errors

• VideoInstance mediaCodec failed to get the AudioEngine
• AVAssetReader (audio) create failed
• AVAssetReader.StartReading (audio) failed
• Unhandled value
• Failed to compile a sound asset, ffmpeg was not found.

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/8fc4031ecf43bae3. Report an issue: GitHub.

Appendix: source

Thrown at sources/engine/Stride.Video/Backends/AVFoundationVideoBackend.cs:348

            Instance.NotifyFramePresented();
        }
        finally
        {
            imported?.Dispose();
        }
    }

    private void InitializeAudio(string url, long startPosition, long length)
    {
        var audioTracks = asset.TracksWithMediaType(AVMediaTypes.Audio.GetConstant());
        if (audioTracks == null || audioTracks.Length == 0)
            return;
        var videoComponent = Instance.VideoComponent;
        if (!videoComponent.PlayAudio)
            return;

        var audioEngine = Instance.Services.GetService<IAudioEngineProvider>()?.AudioEngine
            ?? throw new Exception("VideoInstance AVFoundation failed to get the AudioEngine");

        audioSynchronizer = new MediaSynchronizer();
        audioSynchronizer.PlayRange = Instance.PlayRange;
        audioSynchronizer.IsLooping = Instance.IsLooping;
        audioSynchronizer.LoopRange = Instance.LoopRange;

        var isSpatialized = videoComponent.AudioEmitters.Any(x => x != null);
        audioSound = new StreamedBufferSound(audioEngine, audioSynchronizer, url, startPosition, length, isSpatialized);
        audioSynchronizer.RegisterExtractor(audioSound);

        if (isSpatialized)
        {
            if (audioSound.GetCountChannels() == 1)
            {
                foreach (var emitter in videoComponent.AudioEmitters)
                {
                    if (emitter == null)
                        continue;

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