It is. explain yourself. What are you trying to do? Play a music cd? If you lack the knowledge to make a 1:1 duplicate of the cd in question, then the only thing I can think of is to make the individual songs in .wav format.
The question wasn't what file format the tracks on a CD are in, but how to convert a CD so that Gamma can do something with it. Simply reading the question carefully helps.
Since you play a ps1 game I assume that it should work like on a ps1 original console. Therefore the guess that you have to replicate a normal music cd as close as possible? And those are made up of .wav tracks. But Im no expert on emulation so maybe its something Im missing here.