Octopus Binding for Web

Octopus Speech-to-Index Engine

Made in Vancouver, Canada by Picovoice

Octopus is Picovoice's Speech-to-Index engine. It directly indexes speech without relying on a text representation. This acoustic-only approach boosts accuracy by removing out-of-vocabulary limitation and eliminating the problem of competing hypothesis (e.g. homophones)

Compatibility

• Chrome / Edge
• Firefox
• Safari

Restrictions

IndexedDB is required to use Octopus in a worker thread. Browsers without IndexedDB support (i.e. Firefox Incognito Mode) should use Octopus in the main thread.

Installation

Using yarn:

yarn add @picovoice/octopus-web

or using npm:

npm install --save @picovoice/octopus-web

AccessKey

Octopus requires a valid Picovoice AccessKey at initialization. AccessKey acts as your credentials when using Octopus SDKs. You can get your AccessKey for free. Make sure to keep your AccessKey secret. Signup or Login to Picovoice Console to get your AccessKey.

Usage

For the web packages, there are two methods to initialize Octopus.

Public Directory

NOTE: Due to modern browser limitations of using a file URL, this method does not work if used without hosting a server.

This method fetches the model file from the public directory and feeds it to Octopus. Copy the model file into the public directory:

cp ${OCTOPUS_MODEL_FILE} ${PATH_TO_PUBLIC_DIRECTORY}

Base64

NOTE: This method works without hosting a server, but increases the size of the model file roughly by 33%.

This method uses a base64 string of the model file and feeds it to Octopus. Use the built-in script pvbase64 to base64 your model file:

npx pvbase64 -i ${OCTOPUS_MODEL_FILE} -o ${OUTPUT_DIRECTORY}/${MODEL_NAME}.js

The output will be a js file which you can import into any file of your project. For detailed information about pvbase64, run:

npx pvbase64 -h

Octopus Model

Octopus saves and caches your model file in IndexedDB to be used by WebAssembly. Use a different customWritePath variable to store multiple models and set the forceWrite value to true to force overwrite a model file in storage. If the model file (.pv) changes, version should be incremented to force the cached model to be updated.

Either base64 or publicPath must be set to instantiate Octopus. If both are set, Octopus will use the base64 model.

const octopusModel = {
  publicPath: ${MODEL_RELATIVE_PATH},
  // or
  base64: ${MODEL_BASE64_STRING},

  // Optionals
  customWritePath: "octopus_model",
  forceWrite: false,
  version: 1,
}

Initialize Octopus

Create an instance of Octopus in the main thread:

const handle = await Octopus.create(
  ${ACCESS_KEY},
  octopusModel,
  options // optional options
);

Or create an instance of Octopus in a worker thread:

const handle = await OctopusWorker.create(
  ${ACCESS_KEY},
  octopusModel,
  options // optional options
);

Index Audio Frames

The index result is an object holding the metadata information of your audio file. This is used later to search for a phrase.

function getAudioData(): Int16Array {
  ... // function to get audio data
  return new Int16Array();
}

const octopusMetadata = await handle.index(getAudioData());

For processing using worker, you may consider transferring the buffer instead for performance:

const pcm = new Int16Array();
const octopusMetadata = await handle.index(pcm, {
  transfer: true,
  transferCB: (data) => {pcm = data}
});

Search

Using the metadata from the previous step, you can search for a phrase. The result is a list of objects with each element containing the following properties:

• startSec: Start of the matched audio in seconds.
• endSec: End of the matched audio in seconds.
• probability: Probability (confidence) that this matches the search phrase (between 0 and 1).

const result = await handle.search(octopusMetadata, "${SEARCH_PHRASE}");
for (const elem of result) {
  console.log(elem.startSec, elem.endSec, elem.probability);
}

Clean Up

Clean up used resources by Octopus or OctopusWorker:

await handle.release();

Terminate

Terminate OctopusWorker instance:

await handle.terminate();

Demo

For example usage refer to our Web demo application.