FFT Function

hi, me again and still with a simple problem :slight_smile:
project school, i have to make a plugin project by using the fft function and process the input signal, please tell me what should i do first?
already looking for some references in git Hub but still make me confused, just need input process and no output, may i use code from example project? (Simple FFT Example), i have to get the signal real time

The Simple FFT example is a good place to start. It depends what you need to achieve with the FFT but the dsp::FFT can process the signal over complex or real numbers and if you only need magnitude frequency response, you can use the lightweight performFrequencyOnlyForwardTransform() function.

thank you Noah :slight_smile:
can u tell me, how much this function get frequency sample?


and can i copy all the code in fft example and paste it into plugin project?
need your help :slight_smile:

The FFT example uses a FIFO to process the data 60 times a second and displays it as a spectrogram but if you only need to analyse the data, you may not need all of the example code.

What do you mean by โ€œget frequency sampleโ€? The array passed in the performFrequencyOnlyForwardTransform() needs to be twice the size of your FFT data points as it contains both input and output data. You also need to create a FFT object to call the transform on prior to this.

i mean "sample rate"
and what about how make this code as a plugin?

You can get the sample rate from the prepareToPlay() function right before getNextAudioBlock() gets called.

I suppose you could make this as a plugin yes. I suggest starting from a plugin template in the Projucer and gradually implementing the FFT example.

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