App Crashes on Android Build with ObjectDetector using `categoryAllowList`

[ilhamachmada]

Plugin Version or Commit ID

v0.16.1

Unity Version

6000.0.49f1

Your Host OS

Windows 11

Target Platform

Android

[Windows Only] Visual Studio C++ and Windows SDK Version

No response

[Linux Only] GCC/G++ and GLIBC Version

No response

[Android Only] Android Build Tools and NDK Version

No response

[iOS Only] XCode Version

No response

Command Sequences

Description

When trying to build and run object detection on Android using categoryAllowList, the app crashes with a fatal native error inside tensors_to_detections_calculator.cc. This happens only when categoryAllowList is specified — the app works fine without it.

Steps to Reproduce

1. Set up MediaPipe Unity Plugin (com.github.homuler.MediaPipeUnity)
2. Configure ObjectDetectorOptions with categoryAllowList = ["sports ball"]
3. Build and run on Android device
4. App crashes immediately when detection starts

Example Code

public Tasks.Vision.ObjectDetector.ObjectDetectorOptions GetObjectDetectorOptions(
    Tasks.Vision.ObjectDetector.ObjectDetectorOptions.ResultCallback resultCallback = null)
{
    return new Tasks.Vision.ObjectDetector.ObjectDetectorOptions(
        baseOptions: new Tasks.Core.BaseOptions(
            delegate_: Delegate,
            modelAssetPath: ModelPath
        ),
        runningMode: RunningMode,
        maxResults: MaxResults,
        scoreThreshold: ScoreThreshold,
        categoryAllowList: new List<string> { "person", "cat" },
        resultCallback: resultCallback
    );
}

Log

2025/07/28 10:33:58.949 10971 11170 Fatal native F0000 00:00:1753673638.949334   11170 tensors_to_detections_calculator.cc:1183] Check failed: class_index_set_.values.size() == IsClassIndexAllowed(0) ? num_classes_ : num_classes_ - 1 (1 vs. 90) Only all classes  >= class 0  or  >= class 1
2025/07/28 10:33:58.949 10971 11170 Fatal native terminating.
2025/07/28 10:33:58.949 10971 11170 Fatal native F0000 00:00:1753673638.949334   11170 tensors_to_detections_calculator.cc:1183] Check failed: class_index_set_.values.size() == IsClassIndexAllowed(0) ? num_classes_ : num_classes_ - 1 (1 vs. 90) Only all classes  >= class 0  or  >= class 1
2025/07/28 10:33:58.949 10971 11170 Fatal native terminating.

Additional Context

I have tested with both MediaPipeUnityPlugin-all and MediaPipeUnityPlugin-all-stripped — both exhibit the same crashing behavior.

[homuler]

Can you give me a working code?
It would be helpful if the code can be run within the Unity Editor, like the following test code.

MediaPipeUnityPlugin/Packages/com.github.homuler.mediapipe/Tests/EditMode/Tasks/Vision/ObjectDetector/ObjectDetectorTest.cs

Lines 117 to 135 in 5374c45

	[Test]
	public void Detect_ShouldReturnObjectDetectionResult_When_ObjectsAreDetected()
	{
	var options = new ObjectDetectorOptions(
	new BaseOptions(BaseOptions.Delegate.CPU,
	modelAssetBuffer: _objectDetectorModel.Value.bytes),
	runningMode: RunningMode.IMAGE,
	maxResults: 10);
	using (var objectDetector = ObjectDetector.CreateFromOptions(options))
	{
	using (var image = CopyAsImage(_facePicture.Value))
	{
	var result = objectDetector.Detect(image, null);
	Assert.IsTrue(result.detections?.Count > 0);
	Assert.IsTrue(result.detections?.Count <= 10);
	}
	}
	}

In addition, will you tell me which model you're using?