Failure on the first facial scan with FaceLivenessDetector.

[alvarorommel]

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On which framework/platform are you having an issue?

Android

Which UI component?

Liveness

How is your app built?

Android Kotlin

What browsers are you seeing the problem on?

No response

Which region are you seeing the problem in?

No response

Please describe your bug.

The tirst Attempt at Facial Scan (Liveness Check) Always Failed, Regardless of Device.

The following error appeared in the app logs:
“The camera failed to open within the allowed time limit.”

It seemed like the FaceLivenessDetector was trying to access the camera before it was fully ready, causing the device to be unable to activate or access the camera in time.

FaceLivenessDetector is triggered immediately after obtaining the sessionId, which leads to a backend error.

On the backend, the AWS Lambda function failed because the sessionId was sent too quickly. As a result, the issue shown in the image occurred, where the ReferenceImage object was not included. In order for the image to be present, the status had to be SUCCEEDED; in any other state, the object (the image) was not included.

What's the expected behaviour?

We hope that the first facial scan attempt doesn't always fail and that it works as it did in previous versions.

Help us reproduce the bug!

The only change we made was updating the libraries involved in the facial scan.
We had:

implementation 'com.amplifyframework.ui:liveness:1.3.0'  
implementation 'com.amplifyframework:aws-auth-cognito:2.17.0'  
implementation 'com.amplifyframework:core:2.8.1'

We changed to:

implementation 'com.amplifyframework.ui:liveness:1.4.2'  
implementation 'com.amplifyframework:aws-auth-cognito:2.27.4'  
implementation 'com.amplifyframework:core:2.27.4'

Code Snippet

Here is a code example of how FaceLivenessDetector is used:

ResourceAWS.Status.SUCCESS -> {
    loading.dismiss()
    setContent {
        MaterialTheme(
            colorScheme = colores
        ) {
            FaceLivenessDetector(
                sessionId = resource.data.sessionId,
                region = "us-east-1",
                disableStartView = true,
                onComplete = {
                    viewModel.fetchSessionResult(
                        resource.data.sessionId
                    )
                    observeSessionResult()
                },
                onError = { error ->
                }
            )
        }
    }
}

ResourceAWS.Status.ERROR -> {
}

ResourceAWS.Status.LOADING -> {
    loading.show()
}

Console log output

"The camera failed to open within the allowed time limit."

Additional information and screenshots

Tested Solutions:

Introduce a delay before activating FaceLivenessDetector to allow time for the camera to become operational.

Attempt to check if the camera is ready to use: This solution was ineffective because Amplify manages the camera internally and does not provide any method or callback to determine whether the camera is ready.

Automatically retry the facial scan after the first failed attempt: If the error "camera failed to open" occurs, relaunch the scan. While this approach worked, it visibly showed the failure and then reloaded the view.

Introduce a delay within the Lambda function, though this is not recommended since it keeps the Lambda occupied.

[soberm]

Hi @alvarorommel, thanks for opening this issue. This issue is more relevant to our Android repository. I'll be transferring it there for proper handling and resolution.

[vincetran]

Can you provide some more details about your implementation?

The only change we made was updating the libraries involved in the facial scan.

Are you saying that when you were using v1.3.0 of Liveness, everything was working perfectly fine in production but when you started testing updating to v1.4.2, it started to break?

When do you use 1.4.2, can you describe with more details what happens? You launch the FaceLivenessDetector with a session ID and then does it take 5 seconds for the error to occur?

The change that happened between 1.3.0 and 1.4.2 is to add that error handling: https://github.com/aws-amplify/amplify-ui-android/pull/205/files

5 seconds should be more than enough time to open the camera unless there are other factors at play.

[alvarorommel]

Yes, if I use version 1.3.0 of Liveness, it works fine. However, if I upgrade to version 1.4.2 without changing any other code, the issue occurs.
As for your request for more details about my implementation, here they are:
First, in my Activity I create a session after asking for camera permissions, and only if permissions are granted:

fun createSession(callback: GetSessionIDCallback) {
    callback.onLoading()
    val request = RestOptions.builder()
        .addPath("*****")
        .build()
    var result = ""
    Amplify.API.get(request, { response ->
        result = response.data.asString()
        if (!response.code.isSuccessful) {
            callback.onError(response.data.asString())
        } else {
            val value = gson.fromJson(
                result,
                SessionIDResponseModel::class.java
            )
            callback.onResponse(value)
        }
    }, { error ->
        callback.onError(error.message!!)
    })
}

Then, if the session creation is successful, I launch the FaceLivenessDetector as shown above. Finally, if FaceLivenessDetector doesn’t throw an error, I fetch the session results.
I haven’t modified this code since its initial implementation and it never caused problems before. It seems the error-handling changes you introduced are now causing issues in my app.
I’ve attached two short videos showing the behavior in both versions: version 1.3.0 first, and then version 1.4.2.
As you can see, the 1.3.0 video completes a full scan, whereas the 1.4.2 clip abruptly stops after a few seconds. The only variable between them is the SDK version.

amplify_1.3.0.mp4

amplify_1.4.2.mp4

[vincetran]

Thanks for the details! Give us some time to investigate and we'll come back with any findings.