Rhino Speech-to-Intent
Unity API

API Reference for the Rhino Unity SDK.

package: Pv.Unity

Rhino

public class Rhino : IDisposable

Class for the Rhino Speech-to-Intent engine.

Rhino.ContextInfo

public string ContextInfo { get; }

Gets the source of the Rhino context in YAML format. Shows the list of intents, which expressions map to those intents, as well as slots and their possible values.

Returns

• string : Rhino context source.

Rhino.FrameLength

public int FrameLength { get; }

Gets the required number of audio samples-per-frame.

Returns

• int : Required frame length.

Rhino.SampleRate

public int SampleRate { get; }

Get the audio sample rate required by Rhino.

Returns

• int : Required sample rate in Hz.

Rhino.Version

public string Version { get; }

Gets the version number of the Rhino library.

Returns

• string : Version of Rhino.

Rhino.Create()

public static Rhino Create(
        string accessKey,
        string contextPath,
        string modelPath = null,
        float sensitivity = 0.5f,
        float endpointDurationSec = 1.0f,
        bool requireEndpoint = true)

Factory method for creating instances of Rhino.

Parameters

• accessKey string : AccessKey obtained from Picovoice Console.
• contextPath string : Absolute path to the Rhino context file (.rhn).
• modelPath string : Absolute path to the file containing model parameters (.pv). If not set, default model is used.
• sensitivity float : Inference sensitivity. A higher sensitivity value results in fewer misses at the cost of (potentially) increasing the erroneous inference rate. Sensitivity should be a floating-point number within 0 and 1.
• endpointDurationSec float : Endpoint duration in seconds. An endpoint is a chunk of silence at the end of an utterance that marks the end of spoken command. It should be a positive number within [0.5, 5]. A lower endpoint duration reduces delay and improves responsiveness. A higher endpoint duration assures Rhino doesn't return inference pre-emptively in case the user pauses before finishing the request.
• requireEndpoint bool : If set to true, Rhino requires an endpoint (a chunk of silence) after the spoken command. If set to false, Rhino tries to detect silence, but if it cannot, it still will provide inference regardless. Set to false only if operating in an environment with overlapping speech (e.g. people talking in the background)

Returns

• Rhino : An instance of the Rhino Speech-to-Intent engine.

Throws

• RhinoException : If an error occurs while creating an instance of the Rhino Speech-To-Intent engine.

Rhino.Dispose()

public void Dispose()

Explicitly releases resources acquired by Rhino.

Rhino.GetInference()

public Inference GetInference()

Gets inference results from Rhino. Should only be called after Process() returns true, otherwise Rhino has not yet reached an inference conclusion.

Returns

• Inference : An object containing the results of a Rhino Inference.

Throws

• RhinoException : If inference retrieval fails.

Rhino.Process()

public bool Process(short[] pcm)

Processes a frame of audio and emits a flag indicating if the inference is ready. The number of samples-per-frame can be obtained by calling .FrameLength. The incoming audio needs to have a sample rate equal to .SampleRate and be 16-bit linearly-encoded. Rhino operates on single-channel audio.

Parameters

• pcm short[] pcm : A frame of audio samples.

Returns

• bool : Indicates whether Rhino has an inference ready or not.

Throws

• RhinoException : If there is an error while processing the audio frame.

Rhino.Reset()

public void Reset()

Resets the internal state of Rhino. It should be called before the engine can be used to infer intent from a new stream of audio.

Throws

• RhinoException : If an error occurs while resetting.

Inference

public class Inference

Class for storing data from a Rhino inference result.

Inference.IsUnderstood

public bool IsUnderstood { get; }

Indicates whether Rhino understood what it heard based on the context.

Inference.Intent

public string Intent { get; }

If IsUnderstood, name of intent that was inferred.

Inference.Slots

public Dictionary<string, string> Slots { get; }

If IsUnderstood, dictionary of slot keys and values that were inferred.

RhinoException

public class RhinoException : Exception

Exception thrown if an error is encountered by the Rhino engine.

Exceptions:

public class RhinoActivationException           : RhinoException { }
public class RhinoActivationLimitException      : RhinoException { }
public class RhinoActivationRefusedException    : RhinoException { }
public class RhinoActivationThrottledException  : RhinoException { }
public class RhinoIOException                   : RhinoException { }
public class RhinoInvalidArgumentException      : RhinoException { }
public class RhinoInvalidStateException         : RhinoException { }
public class RhinoKeyException                  : RhinoException { }
public class RhinoMemoryException               : RhinoException { }
public class RhinoRuntimeException              : RhinoException { }
public class RhinoStopIterationException        : RhinoException { }

RhinoManager

public class RhinoManager

High-level API for the Rhino Speech-to-Intent engine. It handles audio recording and processing in real-time, and notifies the client when an inference has been made.

RhinoManager.IsAudioDeviceAvailable

public bool IsAudioDeviceAvailable { get; }

Checks whether there are any audio capture devices available.

Returns

• bool : If any available audio capture device are available.

RhinoManager.IsRecording

public bool IsRecording { get; }

Checks whether RhinoManager is capturing audio or not.

Returns

• bool : If recording or not.

RhinoManager.Create()

public static RhinoManager Create(
        string accessKey,
        string contextPath,
        Action<Inference> inferenceCallback,
        string modelPath = null,
        float sensitivity = 0.5f,
        float endpointDurationSec = 1.0f,
        bool requireEndpoint = true,
        Action<RhinoException> processErrorCallback = null)

Factory method for creating instances of RhinoManager.

Parameters

• accessKey string : AccessKey obtained from Picovoice Console.
• inferenceCallback Action<Inference> : A callback that is invoked when Rhino has made an inference.
• contextPath string : Absolute path to the Rhino context file (.rhn).
• modelPath string : Absolute path to the file containing model parameters (.pv). If not set, default model is used.
• sensitivity float : Inference sensitivity. A higher sensitivity value results in fewer misses at the cost of (potentially) increasing the erroneous inference rate. Sensitivity should be a floating-point number within 0 and 1.
• endpointDurationSec float : Endpoint duration in seconds. An endpoint is a chunk of silence at the end of an utterance that marks the end of spoken command. It should be a positive number within [0.5, 5]. A lower endpoint duration reduces delay and improves responsiveness. A higher endpoint duration assures Rhino doesn't return inference pre-emptively in case the user pauses before finishing the request.
• requireEndpoint bool : If set to true, Rhino requires an endpoint (a chunk of silence) after the spoken command. If set to false, Rhino tries to detect silence, but if it cannot, it still will provide inference regardless. Set to false only if operating in an environment with overlapping speech (e.g. people talking in the background).
• processErrorCallback Action<RhinoException> : A callback that reports errors that are encountered while the engine is processing audio.

Returns

• RhinoManager : An instance of the RhinoManager class.

Throws

• RhinoException : If an error occurs while creating an instance of the Rhino Speech-To-Intent engine.

RhinoManager.Delete()

public void Delete()

Free resources that were allocated to 'RhinoManager'.

RhinoManager.Process()

public void Process()

Starts audio capture and intent inference. Audio capture and processing is stopped automatically once Rhino has made an inference.

Throws

• RhinoException : If there is an error while processing the audio frame.