A callback interface to interact with the recognition service: input the data and obtain the results. This interface and its methods are to be implemented on the client side.
public static interface Callback
Note: While the service is being stopped, frames continue to be requested and calls to this callback continue to be queued, so this callback can be called after the service has been stopped.
Reports an error.
Delivers the result after recognizing the frames that were provided.
Requests the latest video frame.