Qt has long provided some support for multimedia on the platforms it supports in C++ through the inclusion of its Phonon library. In Qt 5.0 and beyond, Qt Quick provides several objects to interact with the native support Qt and the underlying platform provides. Using these QML components, you can:

What's actually supported by Qt depends on the target platform; for example, if the hardware doesn't have a camera, you can't display a camera viewfinder or take pictures. In practice, the level of support varies further; for example, as I write this, multimedia and support on Windows is very poor. Moreover, the actual format of the audio and video which Qt can play back depends on the libraries installed with Qt, which depend on the target platform. Platforms such as Linux might require additional libraries to fully support the audiovisual...