Rhino Speech-to-Intent
Angular Quick Start

Platforms

• Chrome & Chromium-based browsers
• Edge
• Firefox
• Safari

Requirements

• Picovoice Account and AccessKey
• Node.js 16+
• Angular 13+
• npm

Picovoice Account & AccessKey

Signup or Login to Picovoice Console to get your AccessKey. Make sure to keep your AccessKey secret.

Quick Start

Setup

1. Install Node.js.

2. Install the npm packages:

   • @picovoice/rhino-angular
   • @picovoice/web-voice-processor

npm install @picovoice/rhino-angular @picovoice/web-voice-processor

Usage

To initialize Rhino Speech-to-Intent you'll need a context file (.rhn) as well as a model file (.pv). Place these files in the project's public directory or generate a base64 representation of the file using the built-in script:

npx pvbase64 -i ${RHINO_INIT_FILE} -o ${BASE64_OUTPUT_FILE}

Pass the path to the file (relative to the public directory) or use the base64 string:

const rhinoFile = {
  publicPath: "${FILE_RELATIVE_PATH}",
  // or
  base64: "${FILE_BASE64_STRING}",
}

Add the RhinoService that infers intent from spoken commands within a given context to an Angular component:

import { Subscription } from "rxjs"
import { RhinoService } from "@picovoice/rhino-angular"

const contextFileBase64 = // base64 of Rhino context file (.rhn)
const modelFileBase64 = // base64 of Rhino model file (.pv)

export class VoiceWidget {
  private contextInfoSubscription: Subscription
  private inferenceSubscription: Subscription
  private isLoadedSubscription: Subscription
  private isListeningSubscription: Subscription
  private errorSubscription: Subscription

  constructor(private rhinoService: RhinoService) {
    this.contextInfoSubscription = rhinoService.contextInfo$.subscribe(
      contextInfo => {
        console.log(contextInfo);
      });
    this.inferenceSubscription = rhinoService.inference$.subscribe(
      inference => {
        console.log(inference);
      });
    this.isLoadedSubscription = porcupineService.isLoaded$.subscribe(
      isLoaded => {
        console.log(isLoaded);
      });
    this.isListeningSubscription = porcupineService.isListening$.subscribe(
      isListening => {
        console.log(isListening);
      });
    this.errorSubscription = porcupineService.error$.subscribe(
      error => {
        console.error(error);
      });
  }

  async ngOnInit() {
    await this.rhinoService.init(
      ${ACCESS_KEY},
      { base64: contextFileBase64 },
      { base64: modelFileBase64 },
    )
  }

  async process() {
    await this.rhinoService.process();
  }

  ngOnDestroy() {
    this.contextInfoSubscription.unsubscribe();
    this.inferenceSubscription.unsubscribe();
    this.isLoadedSubscription.unsubscribe();
    this.isListeningSubscription.unsubscribe();
    this.errorSubscription.unsubscribe();
    this.rhinoService.release();
  }
}

To start detecting an inference, run the process function:

await this.rhinoService.process();

The process function initializes WebVoiceProcessor. Rhino Speech-to-Intent will then listen and process frames of microphone audio until it reaches a conclusion, then update the inference subscription with the latest result. Once a conclusion is reached, Rhino will enter a paused state. From the paused state, call process again to detect another inference.

Custom Contexts

Create custom contexts in the Picovoice Console using the Rhino Speech-to-Intent Grammar. Train and download a Rhino context file (.rhn) for the target platform Web (WASM). This model file can be used directly with publicPath, but, if base64 is preferable, convert the .rhn file to a base64 JavaScript variable using the built-in pvbase64 script:

npx pvbase64 -i ${CONTEXT_FILE}.rhn -o ${CONTEXT_BASE64}.js -n ${CONTEXT_BASE64_VAR_NAME}

Similar to the model file (.pv), context files (.rhn) are saved in IndexedDB to be used by Web Assembly. Either base64 or publicPath must be set for the context to instantiate Rhino. If both are set, Rhino Speech-to-Intent will use the base64 model.

const contextModel = {
  publicPath: "${CONTEXT_RELATIVE_PATH}",
  // or
  base64: "${CONTEXT_BASE64_STRING}",
}

Non-English Languages

In order to use Rhino Speech-to-Intent with different languages you need to use the corresponding model file (.pv) for the desired language. The model files for all supported languages are available in the Rhino GitHub repository.

Demo

For the Rhino Speech-to-Intent Angular SDK, there is an Angular demo project available on the Rhino GitHub repository.

Setup

Clone the Rhino Speech-to-Intent repository from GitHub:

git clone --recurse-submodules https://github.com/Picovoice/rhino.git

Usage

1. Install the dependencies, and use the start script with a language code to start a local web server hosting the demo in the language of your choice (e.g. pl -> Polish, ko -> Korean). To see a list of available languages, run start without a language code.

cd rhino/demo/angular
npm install
npm run start ${LANGUAGE}

2. Open http://localhost:4200 to view it in the browser

3. Enter your AccessKey and click Init Rhino to start the demo

Resources