如何在不保存的情况下在 Android 工作室中以 bitmap 或 ByteBuffer 的形式访问流式摄像机视频？（Java）

Question

I am building an app in Android studio in Java where I want to access realtime video from camera without saving it and get it as a ByteBuffer. Any help will be appreciated.

Answer 1

It Depends on the API you use (CameraX, Camera2). If you use Camera2 API the general flow would be:

1. Open a Camera:

val manager = getSystemService(CAMERA_SERVICE) as CameraManager
manager.openCamera(cameraId, cameraStateCallback, cameraHandler)

2. Wait for the camera to open:

private val cameraStateCallback: CameraDevice.StateCallback = object : CameraDevice.StateCallback() {
    override fun onOpened(cameraDevice: CameraDevice) {
        //Start a capture session
    }

    override fun onDisconnected(cameraDevice: CameraDevice) {
        cameraOpenCloseLock.release()
        cameraDevice.close()
    }

    override fun onError(cameraDevice: CameraDevice, error: Int) {
        cameraOpenCloseLock.release()
        cameraDevice.close()
    }
}

3. Then start a capture session, and using ImageReader to receive images.

You can check this project for a small basic working example of the entire flow.