Frequenz Analyse FFT
I'm looking for the fastest solution to output from the microphone the strongest current frequency of the frequency spectrum on a text label.
Open microphone Internal or external
Save it to a file
Detect the strongest frequency (25 - 15000 Hz)
Save results in textlabel.
Loop Recording to stop.
Close the file
Hallo! Audio recording is easy with QAudioRecorder Class. For the analyzing part you'll need to find other 3rd party stuff unless you're willing to reinvent the wheel.
This a good starting point as it allows to select device etc.
Or this old Qt4 spectrum analyser example.