I'm trying to playback MP4/AAC files through QtMulitmediaKit. It works on many platforms, but not on Windows 7. The files can be played without problems using the preinstalled Windows Media Player.
If I install the "K-Lite Codec Pack - Basic " playback through QtMultimediaKit works as expected. However Windows 7 comes with a preinstalled DirectShow filter for MP4/AAC that should make installing another filter unnecessary.