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Topic: SONIA FFT TEST (Read 1909 times) |
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christian
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Re: SONIA FFT TEST
« Reply #16 on: Nov 3rd, 2003, 4:04pm » |
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yes!!!  ))
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christian
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Re: SONIA FFT TEST
« Reply #17 on: Nov 3rd, 2003, 4:05pm » |
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thank you for working so straight
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elaine
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Re: SONIA FFT TEST
« Reply #18 on: Jan 30th, 2004, 9:22am » |
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hi all,
i'm doing a project that wants to analyze the frequency from a speech. thus, i'm using the LiveInput.getSpectrum to get the FFTs bands.
and now, just want to check if my understanding is correct:
the LiveInput engine has a default sampling rate of 44100Hz and a 1024 size of FFT spectrum. that means, the engine will recognize any source with frequencies lie between 0Hz to 22050Hz (44100/2) and display it proportionally in the spectrum??
so, if i play a sound file and want to identify the frequencis, says from 2000Hz to 4000Hz, i write the following..
float fft_bands = 1024;
float sr = 44100; //sampling rate
float optimal_freq_min = 2000;
float optimal_freq_max = 4000;
int count_freq_min = int(fft_bands * optimal_freq_min/(sr/2));
int count_freq_max = int(fft_bands * optimal_freq_max/(sr/2));
int count_freq_range = count_freq_max - count_freq_min;
...
for ( int i = 0; i < LiveInput.spectrum.length; i++){
if ((LiveInput.spectrum[i]>250) && (i>count_freq_min) && (i<count_freq_max))
count++;
}
...
the above code works, but the count value is out of my expectation even i play a sine wave of 200Hz. i expect to get a ZERO count but i got a non-zero count instead...
could anyone can me some suggestions?
thanks in advance,
elaine
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