1. To extract the digital representation of a piece of music from an audio CD. Software that does this is often called a “CD ripper”.
2. [Amiga hackers] To extract sound or graphics from a program that they have been compiled/assembled into, or which generates them at run-time. In the case of older Amiga games this entails searching through memory shortly after a reboot. This sense has been in use for many years and probably gave rise to the (now more common) sense 1.