Voice enabling Delphi Android and iOS apps
Last reviewed: 10/1/2020
HOW Article ID: H052014
The information in this article applies to:
- SpeechKit 9
Voice enabling Delphi Android and iOS applications is easier with SpeechKit classes for managing speech recognition and speech synthesis.
Develop Delphi applications that speak and listen using your favorite version of Delphi. SpeechKit includes Delphi units comprised of the Delphi classes that manage recognizers and synthesizers. These are common classes, methods, and events across all platforms.
SpeechKit includes an Object Pascal source file Chant.SpeechKit.pas comprised of the Object Pascal classes that manage speech recognition and speech synthesis. It also includes an Object Pascal source file Chant.Shared.pas comprised of common Object Pascal classes that all Chant libraries use.
To access the SpeechKit Object Pascal classes within your application, first add a project reference to the SpeechKit Object Pascal source files:
- Within your Delphi project, select Project Options.
- Select the Delphi compiler options.
- Add Search path reference to the SpeechKit unit source file director: C:\Program Files\Chant\SpeechKit 9\Delphi\source.
- Add unit output path reference to the local directory with a period '.' character.
To access the SpeechKit Object Pascal classes within your application, add a reference to the Chant.Shared, and Chant.SpeechKit units in your uses clause.
unit Unit1; interface uses ..., Chant.Shared, Chant.SpeechKit;
Instantiate SpeechKit and set the license properties.
// Instantiate SpeechKit object _SpeechKit := TSpeechKit.Create(); if (_SpeechKit <> nil) then begin // Set license properties //_SpeechKit.SetLicense('LicenseRegistrationNumber', 'LicenseSerialNumber'); // Else, for evaluation, set only evaluation serial number _SpeechKit.SetLicense('', 'EvaluationSerialNumber'); end;
Event callbacks are the mechanism in which the class object sends information back to the application such as speech recognition occurred, audio playback finished, or there was an error.
procedure TForm1.Recognition(Sender: TObject; Args: TRecognitionDictationEventArgs); begin If ((Args <> nil) and (Length(Args.Text) > 0)) then begin ... end; end;
The following are Delphi project configuration and application implementation considerations for targeting Android devices.
SpeechKit includes Android compatible jar libraries required by the SpeechKit Delphi classes.
Right click the Libraries folder in your Android Target Platform and select the Add... option to add the following SpeechKit jars to your project:
- Program Files\Chant\SpeechKit 9\Android\lib\speechkit.jar and
- Program Files\Chant\SpeechKit 9\Android\lib\chant-shared.jar.
Additional Delphi Android units may be required such as Androidapi.Helpers to access the application context and Androidapi.Jni.Os and Androidapi.JNIBridge for permissions.
Speech recognition requires the user to grant RECORD_AUDIO permission. Add the appropriate permission in the manifest file by selecting Project->Options->Application->Uses Permission and setting Record audio to true.
Speech synthesis streamed to a file requires WRITE_EXTERNAL_STORAGE permission. Add the appropriate permission in the manifest file by selecting Project->Options->Application->Uses Permission and setting Write external storage to true.
The following are Delphi project configuration and application implementation considerations for targeting iOS devices.
SpeechKit Static Library
SpeechKit includes an iOS compatible static library required by the SpeechKit Object Pascal classes. Copy the libChantSpeechKit.a to your project folder from C:\Program Files\Chant\SpeechKit 9\iOS\lib (do not add it to the project).
Add static library linking options to your project by selecting Project->Options->Building->Delphi Compiler->Linking->Options passed to the LD Linker->Value from "All configurations - iOS Device 64-bit":
SpeechKit includes Object Pascal source files iOSapiChantSpeechKit.pas and Chant.SpeechKit.Bridge.pas that serve as a bridge for the Delphi class to communicate with iOS.
Add the SpeechKit Object Pascal classes to your application project:
- Within your Delphi project, select Project->Add to Project.
- Navigate to C:\Program Files\Chant\SpeechKit 9\Delphi\source.
- Add iOSapi.ChantSpeechKit.pas and Chant.SpeechKit.Bridge.pas to the project.
Speech recognition requires the user to grant permission for speech recognition and microphone usage. Add the appropriate permission via version string key values by selecting Project->Options->VerionInfo and setting string values for NSSpeechRecognitionUsageDescription and NSMicrophoneUsageDescription.
Verify that you have the necessary iOS development prerequisites and configured them for development per the RAD Studio Delphi documentation.
There may be additional iOS frameworks required by the iOS for an application to use Speech Recognition. To verify or add them to your SDK, select Tools->Options->Deployment->SDK Manager->iOS Device 64-bit.
Scroll through the list to verify or add the following Frameworks to your project:
- Click the Update Local File Cache button to bring them from your device into the C++Builder environment.
- Click the Save button to save changes to the environment.