analyse

#!/usr/bin/octave -f

pkg load signal;

input = argv(){1};
[~, name] = fileparts(input);

[y, fs] = audioread(input);
[h, hf] = freqz(y, 1, 65536, fs);
[g, gf] = grpdelay(y, 1, 65536, fs);
gain_db = mag2db(abs(h));
phase = rad2deg(unwrap(angle(h)));
grpdelay_ms = g / fs * 1000;

fig = figure("Name", input, "position", [0, 0, 400, 800]);

subplot(3, 1, 1);
plot(hf, gain_db);
set(gca, "XScale", "log");
grid on;
title("Frequency Response");
xlabel("Frequency (Hz)");
ylabel("Magnitude (dB)");
axis([1, fs/2, -20, 20]);

subplot(3, 1, 2);
plot(hf, phase);
set(gca, "XScale", "log");
grid on;
title("Phase Response");
xlabel("Frequency (Hz)");
ylabel("Phase (degrees)");
axis([1, fs/2, -180, 180]);

subplot(3, 1, 3);
plot(gf, grpdelay_ms);
set(gca, "XScale", "log");
grid on;
title("Group Delay");
xlabel("Frequency (Hz)");
ylabel("Group Delay (ms)");
axis([1, fs/2, 0, 10]);

print(fig, [name ".png"], "-dpng");