Quiet.js (GitHub: brian-armstrong/quiet-js, License: MIT)
Quiet.js is a javascript binding for libquiet.
In other words it’s a library for sending and receiving data via sound card.
It can functions via either speakers or a cable, for instance a 3.5mm mini jack.
Quiet comes included with a few transmissions profiles which configure quiet’s transmitter and receiver.
For speaker transmission, there is a profile which transmits around the 19kHz range.
For transmissions via cable, quiet.js has profiles which offer speeds of at least 40 kbps.
The transmission functionality is available for all evergreen browsers.
Because this project is still very young it is not available via npm yet. There is already an issue logged by the developer himself to implement exports so it can be published to npm.
Quiet-js includes a blob of libquiet as well as a javascript binding, which are compiled by Emscripten. The bindings must be loaded before the compiled portion. The recommended way to include Quiet in your project is:
<script type="text/javascript" src="quiet.js"></script>
<script type="text/javascript" src="my_app.bundle.js"></script>
<script async type="text/javascript" src="quiet-emscripten.js"></script>
The developer highly recommends to also include libfec.js. An enscripted version of libfec which can be installed using npm. When libfec is not included, quiet.js will not be able to use any profiles which use convolutional codes or Reed-Solomon error correction.