There are two options for the final project:
The goal of the final project is to do something that's less of a toy problem and closer to a real problem, and to use an external library. In the first option you use libsndfile and in the second option you use libnetpbm.
Because the labs don't have soundcards available for us, most of you will choose the second option. Still, you are welcome to choose the first option if you have a way to hear the sound files.