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.
Frames can be converted to standard timings. There are CD_FPS frames per second, so SDL_CDtrack.length/CD_FPS=length_in_seconds.
SDL_CD