From 1fdcf8dfa3c7d9e8e88f2bab7c2a830bdd467bbb Mon Sep 17 00:00:00 2001
From: Loic Delattre <loicdelattre38@gmail.com>
Date: Fri, 24 Mar 2023 09:44:27 +0100
Subject: [PATCH] spectrogram and FT times test

---
 FT_times.m                 |  19 ++++++++++++++++
 frequencySpectrum_noplot.m |  44 +++++++++++++++++++++++++++++++++++++
 sound/output.wav           | Bin 98312 -> 98312 bytes
 spectral_analysis.m        |   9 ++++++++
 4 files changed, 72 insertions(+)
 create mode 100644 FT_times.m
 create mode 100644 frequencySpectrum_noplot.m
 create mode 100644 spectral_analysis.m

diff --git a/FT_times.m b/FT_times.m
new file mode 100644
index 0000000..d18fccf
--- /dev/null
+++ b/FT_times.m
@@ -0,0 +1,19 @@
+clear all
+close all
+clc
+
+[y, fs] = audioread("sound/modulator22.wav");
+times = [];
+item_num = 20;
+for j = 1:item_num
+  localtime = [];
+  for i = 0:1
+    t0 = clock ();
+    frequencySpectrum_noplot(y, fs, 0); %true does FFT, false DFT
+    localtime(i+1) = etime (clock (), t0);
+  endfor
+  times = [times; localtime];
+endfor
+
+printf('Average DFT time: %d \n', mean(times(1:item_num, 1)))
+printf('Average FFT time: %d \n', mean(times(1:item_num, 2)))
\ No newline at end of file
diff --git a/frequencySpectrum_noplot.m b/frequencySpectrum_noplot.m
new file mode 100644
index 0000000..fc4cd51
--- /dev/null
+++ b/frequencySpectrum_noplot.m
@@ -0,0 +1,44 @@
+function [power, duration] = frequencySpectrum_noplot(signal, fs, pad)
+%%%%%%%%%%%%%%%%%%
+%function power = frequencySpectrum(signal, fs, pad)
+%
+% Task: Display the power spectrum (lin and log scale) of a given signal
+%
+% Input:
+%	- signal: the input signal to process
+%	- fs: the sampling rate
+%	-pad: boolean if true, signal is padded with 0 to the next power of 2 -> FFT instead of DFT
+%
+% Output: 
+%	- power: the power spectrum
+%	
+%
+% Guillaume Gibert, guillaume.gibert@ecam.fr
+% 25/04/2022
+%%%%%%%%%%%%%%%%%%
+
+n = length(signal);        % number of samples
+
+if (pad)
+	n = 2^nextpow2(n);
+end
+
+tic
+y = fft(signal, n);% compute DFT of input signal
+duration = toc;
+
+power = abs(y).^2/n;    % power of the DFT
+
+[val, ind] = max(power); % find the mx value of DFT and its index
+
+t=0:1/fs:(n-1)/fs; % time range
+%pad signal with zeros
+if (pad)
+	signal = [ signal; zeros( n-length(signal), 1)];
+end
+
+f = (0:n-1)*(fs/n);     % frequency range
+
+
+
+
diff --git a/sound/output.wav b/sound/output.wav
index e1ea9637bfb0a07dac2763890515ea69e66561c4..b00d743181d8c9e85274adf97c7e61c0bb90b132 100644
GIT binary patch
delta 23
ecmeBZVC!gLn;^k1sLjBj6vogfzg3>`Wjz2%;|5&-

delta 23
ecmeBZVC!gLn;^mNvW9`7BZ9F}eycp=%X$D;PzQPd

diff --git a/spectral_analysis.m b/spectral_analysis.m
new file mode 100644
index 0000000..c79bb80
--- /dev/null
+++ b/spectral_analysis.m
@@ -0,0 +1,9 @@
+clear all
+close all
+clc
+
+[y, fs] = audioread("sound/modulator22.wav");
+%frequencySpectrum(y, fs, 0); %true does FFT, false DFT
+step_size = 5; %ms
+window_size = 30;%ms
+spectrogram(y, fs, step_size, window_size)
\ No newline at end of file