Integration-Testing an audiomixer-based Application with an fft/spectrum

[MaZderMind]

Hi there,

I'm working on a complex Application that mixes together various
RTP-Streams based n network Control-Input.

I'd like to integration-test complex mixing scenarios, by sending in
Streams of Test-Audio together with Control-Input and checking what
comes out the other end.

I thought about putting in sine-waves with different frequencies with an
audiotestsrc and having the spectrum-Element generate an FFT on the
output, searching for the correct Peaks.

The spectrum-Element unfortunately does not not specify the actual
Frequency-Range it's analyzing and I didn't find the correct place in
the code for it, which makes me think that it might not be the optimal
choice for these tests.

Therefor I'd like to ask if others have already implemented similar
Tests or have different Ideas.

- Peter