# [MSEide-MSEgui-talk] About MSE and FFT.

```Hello Martin.

I have some questions about mse-fft...```
```
But sorry if some are stupid, I do my first steps with tscopesamplerfft and
tsigscopefft.

Let's go.

There is a buffer of float filled by the input of a sound card, or/and by a
decoded audio file, or/and by a custom sine wave, etc...

I would like to analyse that buffer (array of float = the samples).

Can mse fft analyse other sources than from mse audio ? (huh, like for example
from uos...)

Concretely, how to analyze the array of float (the samples) to get the
frequencies that produce that array, what is the 1, 2, 3, 4 trick ?

Let's begin with something simple: a unique sine wave of 440 htz produced by a
math function.

If a array[0..1023] of float was filled, with samplerate 44100, by a sine-wave
of 440 htz, if you do not know the freq of the sine wave (only the sample
rate), how a fft can retreive the frequency of the signal ?
How many array[0..1023] of float are needed to give a good result ?

And to continue with something more complicated, if the buffer was filled by
the input of a sound card (mic or aux, here a string of guitar), how to
get/note the main frequency (for tuning if needed) ?

I would like, for each guitar string, design the "ideal" sine wave (440 htz for
la) in green, and design the live-sine wave of the guitar in red.  While tuning
the string, when both green and red waves are equal, then it is tuned. But a [
+/- the note ] like classic tuners do is good too.

And a spectrum/peak 16 bands for audio files/input mic would be very welcome
too.
I can do it with uos but I am courious how you propose to do it with mse-fft
(and how fast it is).

OK, back to mse noisegen demo.
What is scrollbar "crest" ?
What king of average is done with checkbox "average" ?

Thanks.

Fre;D

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