This library uses liquid SDR to transmit data through sound. This makes it suitable for sending data across a 3.5mm headphone jack or via speaker and mic.
Quiet can build standalone binaries for encoding/decoding data via .wav files or for streaming through your soundcard via PortAudio. It can also be built as a library to be consumed by other C programs.
- Liquid DSP Be sure to work from the devel branch
- libfec (optional but strongly recommended)
- libsndfile (optional)
- PortAudio (optional)
With the dependencies installed, run
./bootstrap provided by this library, which will create a
build directory and invoke cmake. If you would like to install it after building, do
cd build && make install.
The encoding and decoding processes are controlled by the profiles in
quiet-profiles.json. Each profile contains a complete set of parameters such as modem type and error correction.
For cable transmission, use the
cable- profiles. These will attempt to use nearly the full spectrum provided by your soundcard. As such, they contain many audible frequencies and should not be used on channels that could be heard by people.
ultrasonic- profiles encode data through a very low bitrate, but the audio content lies above 16kHz, which should pass through audio equipment relatively well while being inaudible to the average person. This is a good option for sending data through a channel where you would prefer not to disrupt human listeners.
|Chrome (Android)||Supported||Partially Supported|
|Firefox (Android)||Supported||Partially Supported|
|Internet Explorer||Not Supported||Not Supported|
|Safari (iOS)||Supported||Not Supported|
Additionally, the emscripten compiled portion requires a memory initializer,
quiet-emscripten.js.mem. This is loaded asynchronously by
It is strongly recommended to also include libfec.js. An emscripten-compiled version of libfec may be found here or with
npm install libfec. If libfec is not included, then quiet.js will not be able to use any profiles which use convolutional codes or Reed-Solomon error correction.