iPlug2 Forum

No output from FFTW library

Hello,

I am testing some effects in frequency domain with the FFTW library on Windows 10.

I achieve to compile and link the library with the Iplug2 project, it builds successfully.

However, there is no sound, the FFT produces no output.

With the same code, I have created a Juce project and it works.
What could be the issue ?
I can send you the Iplug2 project if you want.

Best Regards.

Make sure you are not writing to the plugin output array before reading the input. Even though it appears the output and input are separate arrays in most (all?) plugins the audio input array and audio output array are the same array.

So, in the case of an FFT, you need to provide buffer arrays for feeding the FFT and storing the output to load back to the plugin audio output array. All of that needs to be delay compensated with SetLatency().

Don’t know how all of this is done in Juce but in iPlug reading and writing to the audio I/O is done with a “for” loop inside ProcessBlock(). The FFT itself should be run outside that loop.

Others here may have more detailed suggestions. I haven’t worked with FFTs in plugins too much.

There is no reason why FFTW wouldn’t work in iPlug2