Hw1 ECE301S11 travis rother - Rhea

Homework 1

Travis Rother

Part 1

% smoke.m
% Author: Travis Rother
% Description: plays beginning of smoke on the water in three different ways
function smoke()
    delta = .00005;

    buf = []; % stores the freq data to be written at the end
    playsmoke(112, 1); % play at normal speed  (Part a)
    playsmoke(224, 1); % play twice as fast    (Part b)
    playsmoke(112, 2); % play with a frequency shift    (Part c)
    
    wavwrite(buf,1/delta,32, 'smoke.wav'); % write to wav file


    function playsmoke(BPM, pitch)
        % define the notes the song uses
        G = note(-2);
        Bf = note(1);
        C = note(3);
        Df = note(4);

        % vector of notes the song plays
        notes = [G Bf C G Bf Df C G Bf C Bf G];

        % corresponding beat values for each note
        beat = [1 1 1.5 1 1 .5 2 1 1 1.5 1 1];

        % play all of the notes
        for i=1:length(notes)
            dur = (60/BPM)*beat(i);
            t = 0:delta:dur;
            z = sin(pitch*2*pi*notes(i)*t);
            sound(z,1/delta);
            buf = [buf; z(:)];
        end
    end

    function freq = note(hsteps)
       freq =  440 * 2^(hsteps/12);
    end
end

Part 2

[data, Fs] = wavread('Beatles.wav');
rev = flipud(data);
sound(rev,Fs);
wavwrite(rev,Fs,'revBeatles.wav');

a) "number 9, number 9, number 9... "
b) Yes I think it is possible that there is a hidden message. To me it sounds like "carry on, gentlemen". Or it could be nothing, just my brain trying to make sense of garbled sounds.