Pi Wave Compressor

The code in this repository enables you to create a graphical interface for recording audio files and compressing them into files that are 10x smaller without compromising audio quality.

Use case details can be found in this journal:

K. Nakamura, D. Hernández, J. M. Cecilia, P. Manzoni, M. Zennaro, J. -C. Cano and C. T. Calafate, "LADEA: A Software Infrastructure for Audio Delivery and Analytics," Mobile Networks and Applications (MONET), Volume 26, Oct 2021, pp. 2048-2054, doi: 10.1007/s11036-021-01747-z

Getting started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes in your Raspberry.

Technical details

• Raspberry Pi 3 B+ the final revision of the third-generation single-board computer.

• Raspberry Pi OS Desktop

• 3.5'' RPi Display

To configure the display and drivers, proceed as follows:

$ sudo rm -rf LCD-show
$ git clone https://github.com/goodtft/LCD-show.git
$ chmod -R 755 LCD-show
$ cd LCD-show/
$ sudo ./LCD35-show

For more information you can check documentation

Prerequisites

This is the basic information required to set up a suitable development environment for a Raspberry Pi 3 B+ device.

You first need to have Python 3 and Pip 3 installed in your device. Check here for the proper instructions and code:

https://www.python.org/download/releases/3.0/

$ sudo apt install python3
$ sudo apt install python3-pip

Additionally, you need to configure the audio output of your Raspberry, depending on the type of headphones you are going to use.

$ sudo raspi-config

Go to <<Advance Options/Audio/Force 3.5mm Jack>> in case you are going to use headphones with that input/output.

Required libraries and packages

• Pyaudio

• Pydub

• Sounddevice

• FFmpeg

• Tkinter

• Matplotlib

$ sudo pip install pyaudio
$ sudo pip install pydub
$ sudo pip install sounddevice
$ sudo apt-get install ffmpeg libav-tools
$ sudo apt-get install libasound-dev portaudio19-dev libportaudio2 libportaudiocpp0
$ sudo apt install python3-tk
$ sudo python3 -m pip install -U matplotlib

Running

Now you can download and install the project in your devices.

First download the .ZIP, extract it in your device.

Open the terminal at the project location and run.

$ sudo python3 touch_scr.py

Files

The code in this folder is written in Python 3 and tested on:

Files contained:

• The Img folder contains all the images required by the graphical interface, as well as the photos of previously registered users.

• The touch_scr.py file is responsible for generating the graphical interface and performing the user interaction actions.

• The rec.py file is tasked with generating, processing, and compressing the audio files.

Experimental

The interface is designed to be highly user-friendly, with the utilization of icons that dynamically enable/disable to effectively guide the user through the entire process of recording an audio message.

Audio messages generated on the Raspberry can be transmitted using LoRa devices through the LoRaCTP protocol.

Authors

• Kiyoshy Nakamura
• Pietro Manzoni

License

This project is licensed under the GNU GPLv3 - see the LICENSE file for details.