typedef struct{ Uint8 id; Uint8 type; Uint32 length; Uint32 offset; } SDL_CDtrack;
SDL_CDtrack stores data on each track on a CD, its fields should be pretty self explainatory. It is a member a the SDL_CD structure.
Note: Frames can be converted to standard timings. There are CD_FPS frames per second, so SDL_CDtrack.length/CD_FPS=length_in_seconds.