JuliusJS

A speech recognition library for the web

JuliusJS is an opinionated port of Julius to JavaScript.
It actively listens to the user to transcribe what they are saying through a callback.

// bootstrap JuliusJS
var julius = new Julius();

julius.onrecognition = function(sentence) {
  console.log(sentence);
};

// say "Hello, world!"
// console logs: `> HELLO WORLD`

Features:

• Real-time transcription
• Use the provided grammar, or write your own
• 100% JavaScript implementation
• All recognition is done in-browser through a Worker
• Familiar event-inspired API
• No external server calls

Quickstart

Using Express 4.0

1. Grab the latest version with bower

• bower install juliusjs --save

1. Include julius.js in your html

• <script src="julius.js"></script>

1. Make the scripts available to the client through your server

var express = require('express'),
  app     = express();

app.use(express.static('path/to/dist'));

1. In your main script, bootstrap JuliusJS and register an event listener for recognition events

// bootstrap JuliusJS
var julius = new Julius();

// register listener
julius.onrecognition = function(sentence) {
  // ...
  console.log(sentence);
};

• Your site now has real-time speech recognition baked in!

Configure your own recognition grammar

In order for JuliusJS to use it, your grammar must follow the Julius grammar specification. The site includes a tutorial on writing grammars.
By default, phonemes are defined in bin/hmmdefs, though you might find other sites more useful as reference.

• Building your own grammar requires the mkdfa.pl script and associated binaries, distributed with Julius.
• On Mac OS X
  • Use ./bin/mkdfa.pl, included with this repo
• On other OS
  • Run emscripten.sh to populate bin with the necessary files

1. Write a yourGrammar.voca file with words to be recognized

• The .voca file defines "word candidates" and their pronunciations.

1. Write a yourGrammar.grammar file with phrases composed of those words

• The .grammar file defines "category-level syntax, i.e. allowed connection of words by their category name."

1. Compile the grammar using ./bin/mkdfa.pl yourGrammar

• The .voca and .grammar must be prefixed with the same name
• This will generate yourGrammar.dfa and yourGrammar.dict

1. Give the new .dfa and .dict files to the Julius constructor

// when bootstrapping JuliusJS
var julius = new Julius('path/to/dfa', 'path/to/dict');

Motivation

Advanced Use

Configuring the engine

Build from source

Developers

Emscripten

Implementation goals

Contributing

• Contributions are welcome! See CONTRIBUTING.md for guidelines.

In the wild

If you use JuliusJS let me know, and I'll add your project to this list.

1. Coming soon...

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JuliusJS is a port of the "Large Vocabulary Continuous Speech Recognition Engine Julius" to JavaScript