CS 101 - Introduction to Computing, Fall 2008

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.

• Gettysburg Address
• The Preamble
• Gettysburg Address 10 seconds
• The Preamble 10 seconds

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.

The functions of

• getSampleValueAt()
• setSampleValueAt()

Lab Assignment 11

Create a Java program that will:

1. Contain a comment indicating
   • your Name,
   • Net-ID,
   • Course Name,
   • Assignment Name and
   • a short description of the assignment

2. 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.
   • Add the background sound file to the foreground sound file, but the volume of the background sound should be one-third of the sound from its original file. 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, stop combining the two sounds once you run out of background sound samples.
   • play (or explore) the resulting sound and prompt the user to save it in a file
   Here are some example sound files you can use with this assignment.
   • Sample Sound Files

   Submittal of the Lab Assignment

   • When saving your program, use a meaningful name like lab11.java.
   • You are also to submit the Java file electronically by using the UNIX turnin command.
   • You are also required to submit the image that you selected the x-start, y-start, x-end and y-end values.

     To use the UNIX turnin command to electronically hand-in your html file using the project name of lab11. To submit the files in lab11.java and BlendIn.jpg for lab11, the turnin command is entered as:

          turnin -c cs101 -p lab11 lab11.java BlendIn.jpg
     

     To verify what you submitted using the turnin command type:

          turnin -c cs101 -p lab11 -v