Rhino Speech-to-Intent
Angular Quick Start

Platforms

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

Requirements

• Picovoice Account and AccessKey
• Node.js 14+
• 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 you'll need a Rhino 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 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 Rhino call process again to detect another inference.

Custom Contexts

Create custom contexts in the Picovoice Console using the Rhino 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 will use the base64 model.

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

Switching Languages

In order to use Rhino 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 Angular SDK, there is a Angular demo project available on the Rhino GitHub repository.

Setup

Clone the Rhino repository from GitHub:

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

Usage

1. Install dependencies and run:

cd rhino/demo/angular
npm install
npm run start

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

Resources