CS 111 - Program Design I

Lab 11

This lab will have you combine two sound files to add a "background" soundtrack to a foreground sound. The following files of the Gettysburg Address and the Preamble of the U.S. Constitution are great foreground sound files.

The background file should be repeated it if is not as long as the foreground file. To do this, if the current index from the foreground sound is a value bigger than the length of the background sound, you need to subtract the length of the background sound from the current index until the result produces a valid array index for background sound. The use of the modulus operator % may help perform this calculation.

We will also want to make the background sound quieter than it originally is, so we wish to make its volume a third of its original value. Here are some good files for the background sound:

Combining Two Sounds Together

To combine two sound files, you simply just add the sample values together.

The only problem occurs if the resulting value goes above 32,767 or below -32,768. A simple solution is to use an if statement to check for this. Two simple if statements can check for this and correct the problem if it occurs. To correct this, just set the value to either 32,767 if the value was greater than 32,767 or set the value to -32768. if the value was less than -32,768.

Lab Assignment 11

Due: Wednesday 4/16/2014 by 11:59 pm

Create a Java program that will:

  1. Be writen using good programming style which includes:
    • Good variable names
    • In-line commenting
    • Proper indentation of program statements
    • Use of blank lines to separate blocks of code.
    • Header block commenting for the program and each method written

      Your header block comment for the program must include the following:

      • Your Name,
      • Net-ID,
      • Course Name,
      • Assignment Name and
      • Day and time of your CS 101 lab section (i.e. Wednesday at 9:00)
      • A short description of the assignment.
Header block comments for each method must include the following:
      • A description of the purpose of the method
      • A listing of the name, type and purpose of every parameter
      • A description of the return value and its type

  1. Contain the main() method that will
    • Prompt the user for the "Foreground" sound file and make a sound object from this file.
    • Prompt the user for the "Background" sound file and make a sound object from this file.
    • Call a method combineSounds()
    • play (or explore) the resulting sound and
    • Prompt the user to save the resulting sound in a file

  1. Contain the method combineSounds() that will
    • Take two sound objects as parameters: the foreground sound and the background sound.
    • Add the background sound to the foreground sound, but the volume of the background sound should be one-third of its original volume. To do this, first divide the background sound sample values by 3 before adding the two values together.
    • check for and correct any "clipping" that may result from the resulting value being greater than 32,767 or less than -32,768.
    • Note: if the background sound file is shorter than the foreground sound file, repeat the background sound as often as needed to give a background sound to the entire foreground sound. Use the 3 second version of the Star Wars Theme in StarWars3.wav or the 3 second version of CantinaBand3.wav to test this out.

  1. You are also to submit the Java file electronically via the assignment link for Lab 11 in BLackboard.
Here are some example sound files you can use with this assignment. -- Main.troy - 2014-04-14
Topic attachments
I Attachment Action Size Date Who Comment
Waveform sound filewav CantinaBand3.wav manage 129.2 K 2014-04-15 - 18:18 UnknownUser  
Waveform sound filewav StarWars3.wav manage 129.2 K 2014-04-15 - 18:18 UnknownUser  
Topic revision: r2 - 2014-04-15 - 18:18:54 - Main.troy
 
Copyright 2016 The Board of Trustees
of the University of Illinois.webmaster@cs.uic.edu
WISEST
Helping Women Faculty Advance
Funded by NSF