CD-ROM Function Reference

Function definitions:

extern int SDL_CDNumDrives(void);

Returns the number of CD-ROM drives on the system

extern const char *SDL_CDName(int drive);

Returns a human-readable, system-dependent identifier for the CD-ROM.
Examples:

• "/dev/cdrom"
• "E:"
• "/dev/disk/ide/1/master"

extern SDL_CD *SDL_CDOpen(int drive);

Opens a CD-ROM drive for access. It returns a drive handle on success, or NULL if the drive was invalid or busy. This newly opened CD-ROM becomes the default CD used when other CD functions are passed a NULL CD-ROM handle.
Drives are numbered starting with 0. Drive 0 is the system default CD-ROM.

extern CDstatus SDL_CDStatus(SDL_CD *cdrom);

This function returns the current status of the given drive.
If the drive has a CD in it, the table of contents of the CD and current play position of the CD will be stored in the SDL_CD structure.

extern int SDL_CDPlayTracks(SDL_CD *cdrom, int start_track, int start_frame, int ntracks, int nframes);

Play the given CD starting at 'start_track' and 'start_frame' for 'ntracks' tracks and 'nframes' frames. If both 'ntrack' and 'nframe' are 0, play until the end of the CD. This function will skip data tracks.
This function should only be called after calling SDL_CDStatus() to get track information about the CD.
For example:

        // Play entire CD:
        if ( CD_INDRIVE(SDL_CDStatus(cdrom)) )
                SDL_CDPlayTracks(cdrom, 0, 0, 0, 0);
        // Play last track:
        if ( CD_INDRIVE(SDL_CDStatus(cdrom)) ) {
                SDL_CDPlayTracks(cdrom, cdrom->numtracks-1, 0, 0, 0);
        }
        // Play first and second track and 10 seconds of third track:
        if ( CD_INDRIVE(SDL_CDStatus(cdrom)) )
                SDL_CDPlayTracks(cdrom, 0, 0, 2, 10);

extern int SDL_CDPlay(SDL_CD *cdrom, int start, int length);

Play the given CD starting at 'start' frame for 'length' frames.
It returns 0, or -1 if there was an error.

int SDL_CDPause(SDL_CD *cdrom);

Pause play -- returns 0, or -1 on error

int SDL_CDResume(SDL_CD *cdrom);

Resume play -- returns 0, or -1 on error

int SDL_CDStop(SDL_CD *cdrom);

Stop play -- returns 0, or -1 on error

int SDL_CDEject(SDL_CD *cdrom);

Eject CD-ROM -- returns 0, or -1 on error

void SDL_CDClose(SDL_CD *cdrom);

Closes the handle for the CD-ROM drive

Structure definitions:

/* The possible states which a CD-ROM drive can be in. */
typedef enum {
        CD_TRAYEMPTY,
        CD_STOPPED,
        CD_PLAYING,
        CD_PAUSED,
        CD_ERROR = -1
} CDstatus;


/* The structure identifying a track on the CD */
typedef struct {
        Uint8 id;               /* Track number */
        Uint8 type;             /* Data or audio track */
        Uint16 length;          /* Length, in frames, of this track */
        Uint32 offset;          /* Offset, in frames, from start of disk */
} SDL_CDtrack;

/* This structure is only current as of the last call to SDL_CDStatus() */
typedef struct SDL_CD {
        int id;                 /* Private drive identifier */
        CDstatus status;        /* Current drive status */

        /* The rest of this structure is only valid if there's a CD in drive */
        int numtracks;          /* Number of tracks on disk */
        int cur_track;          /* Current track position */
        int cur_frame;          /* Current frame offset within current track */
        SDL_CDtrack track[SDL_MAX_TRACKS+1];
} SDL_CD;

---

Useful Macros

/* Given a status, returns true if there's a disk in the drive */
#define CD_INDRIVE(status)      ((int)status > 0)

/* Conversion functions from frames to Minute/Second/Frames and vice versa */
#define CD_FPS  75
#define FRAMES_TO_MSF(f, M,S,F) {                                       \
        int value = f;                                                  \
        *(F) = value%CD_FPS;                                            \
        value /= CD_FPS;                                                \
        *(S) = value%60;                                                \
        value /= 60;                                                    \
        *(M) = value;                                                   \
}
#define MSF_TO_FRAMES(M, S, F)  ((M)*60*CD_FPS+(S)*CD_FPS+(F))