Matlab对wav文件做fft分析

1.代码

% 指定要读取的.wav文件路径
filename = 'jay.wav';

% 使用audioread函数读取.wav文件
[sound_data, sample_rate] = audioread(filename);
sound_data =  sound_data(:, 1);
% 计算音频数据的长度
sound_length = length(sound_data);

% 计算FFT的点数
% fft_points = 2^nextpow2(sound_length);
fft_points = sound_length;

% 执行FFT变换
sound_fft = fft(sound_data, fft_points); % 结果是复数

%%%%%%%%%%%%%%画fft实部的%%%%%%%%%%%%%
subplot(3, 1, 1);
x1 = sample_rate*(0:(fft_points-1))/fft_points;
y1 = sound_fft;
plot(x1, y1);                             % 默认忽略虚部，有两个边带，且幅度有正有负
xlabel('Frequency (Hz)');
ylabel('Magnitude');
title('FFT Spectrum');

%%%%%%%%%%%%%%画fft的幅度值%%%%%%%%%%%%%
subplot(3, 1, 2);
x2 = sample_rate*(0:(fft_points-1))/fft_points;
y2 = abs(sound_fft);
plot(x2, y2);                             % 有两个边带，且幅度有正有负
xlabel('Frequency (Hz)');
ylabel('Magnitude');
title('FFT Spectrum');

%%%%%%%%%%%%%%画fft的幅度值, 只要半个边带%%%%%%%%%%%%%
subplot(3, 1, 3);
x3 = sample_rate*(0:(fft_points/2))/fft_points;
y3 = abs(sound_fft(1:fft_points/2+1));
plot(x3, y3);                             % 有两个边带，且幅度有正有负
xlabel('Frequency (Hz)');
ylabel('Magnitude');
title('FFT Spectrum');