19.09.2024 
Recap In Part 1, we covered PCM audio and superimposing waveforms, and developed an algorithm to combine an arbitrary number of audio streams into one. Now we need to use these ideas to finish a full implementation using Qt Multimedia. Using Qt Multimedia for Audio Device Access So what do we need? Well, we want […]
Author Archives: Matt Aber
Implementing an Audio Mixer, Part 1 Basic DSP with Qt Multimedia
Motivation When using Qt Multimedia to play audio files, it’s common to use QMediaPlayer, as it supports a larger variety of formats than QSound and QSoundEffect. Consider a Qt application with several audio sources; for example, different notification sounds that may play simultaneously. We want to avoid cutting notification sounds off when a new one […]
Formatting Selected Text in QML Quasi-Backporting Qt 6.7 QML cursorSelection to Older Versions
Motivation Let’s say we’re working on a QML project that involves a TextEdit. There’s some text in it: here is some text We want to select part of this text and hit ctrl+B to make it bold: here is some text In Qt Widgets, this is trivial, but not so much in QML – we […]
Introducing: KDSPDSetup Initialize loggers with simple config files and focus on your code's functionality
KDAB’s newest open-source library is now publicly available: KDSPDSetup! KDSPDSetup is a small library written in modern C++ (≥ 20) that initializes objects from the spdlog library by reading a toml configuration file. This makes setting up loggers more convenient and results in cleaner-looking code. Let’s take a look at an example to see how […]
Incredibly Simple QR Generation in QML Wrapping tiny JS libraries in QML to do quick and simple things effortlessly and elegantly.
The Need for Simple & Modular QR Generation in QML Recently, our designer Nuno Pinheiro needed to generate QR codes for an Android app in QML and started asking around about a simple way to do this. The best existing QML solution was QZXing, a Qt/QML wrapper for the 1D/2D barcode image processing library ZXing. […]
Qt 6 WASM: Uploading & Playing Back Audio Files Adapting to the limitations of the web platform and Qt Multimedia
This article walks through an implementation using C++11 or later, Qt 6.5 or later for WebAssembly (multithreaded), and CMake. The browser environment used was Mozilla Firefox 119.0.1 (64-bit) provided by the Mozilla Firefox snap package for Ubuntu. Overview & Motivation Lately, I’ve been working on a small Qt Widgets project to help manage some weekly […]