TextToSpeech

@available(iOS 13.0, *)
@objc
public class TextToSpeech : NSObject

This is the client entry point for the Spokestack Text to Speech (TTS) system. It provides the capability to synthesize textual input, and speak back the synthesis as audio system output. The synthesis and speech occur on asynchronous blocks so as to not block the client while it performs network and audio system activities.

When inititalized, the TTS system communicates with the client either via a delegate that receive events, or via a publisher-subscriber pattern.

// assume that self implements the TextToSpeechDelegate protocol.
let configuration = SpeechConfiguration()
let tts = TextToSpeech(self, configuration: configuration)
let input = TextToSpeechInput()
input.text = "Hello world!"
tts.synthesize(input) // synthesize the provided default text input using the default synthetic voice and api key.
tts.speak(input) // synthesize the same input as above, and play back the result using the default audio system.

Using the TTS system requires setting an API client identifier (SpeechConfiguration.apiId) and API client secret (SpeechConfiguration.apiSecret) , which are used to cryptographically sign and meter TTS API usage.

Show on GitHub

Properties

Initializers

Public Functions

  • Synthesize speech using the provided input parameters and speech configuration, and play back the result using the default audio system.

    Playback is provided as a convenience for the client. The client is responsible for coordinating the audio system resources and utilization required by SpeechPipeline and/or other media playback. The TextToSpeechDelegate.didBeginSpeaking and TextToSpeechDelegate.didFinishSpeaking callbacks may be utilized for this purpose.

    The TextToSpeech class handles all memory management for the playback components it utilizes.

    Note

    Playback will begin immediately after the synthesis results are received and sufficiently buffered.

    Warning

    AVAudioSession.Category and AVAudioSession.CategoryOptions must be set by the client to compatible settings that allow for playback through the desired audio sytem ouputs.

    Declaration

    Swift

    @objc
public func speak(_ input: TextToSpeechInput)

    Parameters

    input

    Parameters that specify the speech to synthesize.
    Show on GitHub

  • Stops playback of the current synthesis result.

    Declaration

    Swift

    @objc
public func stopSpeaking()
    Show on GitHub

  • Synthesize speech using the provided input parameters and speech configuration. A successful synthesis will return a URL to the streaming audio container of synthesized speech to the TextToSpeech‘s delegate.

    Note

    The URL will be invalidated within 60 seconds of generation.

    Declaration

    Swift

    @objc
public func synthesize(_ input: TextToSpeechInput)

    Parameters

    input

    Parameters that specify the speech to synthesize.
    Show on GitHub

  • Synthesize speech using the provided list of inputs. A successful set of synthesises returns a list of synthesis results.

    Declaration

    Swift

    public func synthesize(_ inputs: Array<TextToSpeechInput>) -> AnyPublisher<[TextToSpeechResult], Error>

    Parameters

    inputs

    Return Value

    AnyPublisher<[TextToSpeechResult], Error>

    Show on GitHub

Internal functions

  • Internal function that must be public for Objective-C compatibility reasons.

    Warning

    Client should never call this function.

    Declaration

    Swift

    @available(*, deprecated, message: "Internal function that must be public for Objective-C compatibility reasons. Client should never call this function.")
override public func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?)
    Show on GitHub