iPod database reading/writing

iPod database reading/writing — Functions to read, write, and create an iPod database

Functions

Types and Values

Description

These functions are for reading, writing, creating, and deleting an iPod database and getting the total number of tracks and playlists.

Overview of using an iPod database:

itdb_parse(): read the iTunesDB and ArtworkDB

itdb_write(): write the iTunesDB and ArtworkDB

itdb_parse() will return a Itdb_iTunesDB structure with GLists containing all tracks the playlists in the database. Each track is represented by an Itdb_Track. Each playlist is represented by an Itdb_Playlist. See the Tracks and Playlists sections for details on tracks and playlists, respectively.

Each Itdb_Playlist has a GList called members which contains all of the tracks in the playlist. Tracks referenced in a playlist must also be present in the tracks GList of the Itdb_iTunesDB.

The iPod must contain one master playlist (MPL) containing all tracks accessible on the iPod through the Music->Tracks/Albums/Artists/etc. menu. In addition to the MPL there can be a number of normal playlists accessible through the Music->Playlists menu on the iPod. Tracks that are a member of one of these normal playlists must also be a member of the MPL.

The Podcasts playlist is just another playlist with some internal flags set differently. Tracks in the Podcasts playlist are not normally members of the MPL (so on the iPod they will only show up under the Podcasts menu). All tracks referenced must be in the tracks GList of the Itdb_iTunesDB, however.

Each track may have a thumbnail associated with it. You can retrieve a GdkPixmap of the thumbnail using itdb_artwork_get_pixbuf(). A thumbnail can be added with itdb_track_set_thumbnails(). A thumbnail can be removed with itdb_track_remove_thumbnails(). Please see the Artwork section for more details on artwork related functions and structures.

Be aware that iTunes additionally stores the artwork as tags in the original music file. That's also from where the data is read when artwork is displayed in iTunes, and there can be more than one piece of artwork. libgpod does not store the artwork as tags in the original music file. As a consequence, if iTunes attempts to access the artwork, it will find none, and remove libgpod's artwork. Luckily, iTunes will only attempt to access the artwork if you select a track in iTunes. To work around this, gtkpod keeps a list of the original filename of all artwork and silently adds the thumbnails if they were 'lost'. Your application might want to do something similar, or you can supply patches for (optionally!) adding tags to the original music files.

The Itdb_iTunesDB, Itdb_Playlist and Itdb_Track structures each have userdata and usertype fields that can be used by the application to store additional application-specific data. If userdata is a pointer to an external structure, you can supply a ItdbUserDataDuplicateFunc and a ItdbUserDataDestroyFunc so that this data can be duplicated or freed automatically with a call to the library _duplicate()/_free() functions.

Functions

itdb_new ()

Itdb_iTunesDB *
itdb_new (void);

Creates a new Itdb_iTunesDB with the unknowns filled in to reasonable values.

Returns

a newly created Itdb_iTunesDB to be freed with itdb_free() when it's no longer needed


itdb_free ()

void
itdb_free (Itdb_iTunesDB *itdb);

Free the memory taken by itdb .

Parameters

itdb

an Itdb_iTunesDB

 

itdb_parse ()

Itdb_iTunesDB *
itdb_parse (const gchar *mp,
            GError **error);

Parse the Itdb_iTunesDB of the iPod located at mp

Parameters

mp

mount point of the iPod (eg "/mnt/ipod") in local encoding

 

error

return location for a GError or NULL

 

Returns

a newly allocated Itdb_iTunesDB struct holding the tracks and the playlists present on the iPod at mp , NULL if mp isn't an iPod mount point. If non-NULL, the Itdb_iTunesDB is to be freed with itdb_free() when it's no longer needed


itdb_write ()

gboolean
itdb_write (Itdb_iTunesDB *itdb,
            GError **error);

Write out an iTunesDB. It reassigns unique IDs to all tracks. An existing "Play Counts" file is renamed to "Play Counts.bak" if the export was successful. An existing "OTGPlaylistInfo" file is removed if the export was successful.

Parameters

itdb

the Itdb_iTunesDB to write to disk

 

error

return location for a GError or NULL

 

Returns

TRUE on success, FALSE on error, in which case error is set accordingly.


itdb_set_mountpoint ()

void
itdb_set_mountpoint (Itdb_iTunesDB *itdb,
                     const gchar *mp);

Sets the mountpoint of itdb . Always use this function to set the mountpoint of an Itdb_iTunesDB as it will reset the number of available /iPod_Control/Music/F.. dirs. It doesn't attempt to parse an iPod database that may be present on the iPod at mp .

Calling this function removes the artwork in the Itdb_iTunesDB database using this Itdb_Device which was read from the iPod.

.

Parameters

itdb

an Itdb_iTunesDB

 

mp

new mount point

 

Since: 0.1.3


itdb_get_mountpoint ()

const gchar *
itdb_get_mountpoint (Itdb_iTunesDB *itdb);

Retrieve a reference to the mountpoint of itdb

Parameters

itdb

an Itdb_iTunesDB

 

Returns

the itdb mountpoint, this string shouldn't be freed nor modified

Since: 0.4.0


itdb_init_ipod ()

gboolean
itdb_init_ipod (const gchar *mountpoint,
                const gchar *model_number,
                const gchar *ipod_name,
                GError **error);

Initialise an iPod device from scratch. The function attempts to create a blank database, complete with master playlist and device information as well as the directory structure required for the type of iPod. model_number is used to tell libgpod about the exact iPod model, which is needed for proper artwork writing. model_number can be found from the table returned by itdb_device_get_ipod_info_table (for example). On recent distros with iPods released in the last few years (starting with the iPod Color), it should be fine to pass in a NULL model_number while still getting artwork writing.

Parameters

mountpoint

the iPod mountpoint

 

model_number

the iPod model number, can be NULL

 

ipod_name

the name to give to the iPod. Will be displayed in gtkpod or itunes

 

error

return location for a GError or NULL

 

Returns

TRUE when successful, FALSE if a failure has occurred.

Since: 0.4.0


itdb_tracks_number ()

guint32
itdb_tracks_number (Itdb_iTunesDB *itdb);

Counts the number of tracks stored in itdb

Parameters

itdb

an Itdb_iTunesDB

 

Returns

the number of tracks in itdb


itdb_tracks_number_nontransferred ()

guint32
itdb_tracks_number_nontransferred (Itdb_iTunesDB *itdb);

Counts the number of non-transferred tracks in itdb

Parameters

itdb

an Itdb_iTunesDB

 

Returns

the number of tracks in itdb that haven't been transferred to the iPod yet (ie the number of Itdb_Track in which the transferred field is false)


itdb_playlists_number ()

guint32
itdb_playlists_number (Itdb_iTunesDB *itdb);

Counts the number of playlists stored in itdb

Parameters

itdb

an Itdb_iTunesDB

 

Returns

the number of playlists in itdb (including the master playlist)


ItdbUserDataDestroyFunc ()

void
(*ItdbUserDataDestroyFunc) (gpointer userdata);

Function called to free userdata

Parameters

userdata

A gpointer to user data

 

ItdbUserDataDuplicateFunc ()

gpointer
(*ItdbUserDataDuplicateFunc) (gpointer userdata);

Function called to duplicate userdata

Parameters

userdata

A gpointer to user data

 

Returns

A gpointer

Types and Values

struct Itdb_iTunesDB

struct Itdb_iTunesDB {
    GList *tracks;
    GList *playlists;
    gchar *filename;
    Itdb_Device *device;
    guint32 version;
    guint64 id;
    gint32 tzoffset;
    /* reserved for future use */
    gint32 reserved_int2;
    Itdb_iTunesDB_Private *priv;
    gpointer reserved2;
    /* below is for use by application */
    guint64 usertype;
    gpointer userdata;
    /* functions called to duplicate/free userdata */
    ItdbUserDataDuplicateFunc userdata_duplicate;
    ItdbUserDataDestroyFunc userdata_destroy;
};

Structure representing an iTunes database

Members

GList *tracks;

A list of tracks in the database (Itdb_Track)

 

GList *playlists;

A list of playlists in the database (Itdb_Playlist)

 

gchar *filename;

The filename of the iTunesDB

 

Itdb_Device *device;

iPod device info (Itdb_Device)

 

guint32 version;

The version number of the iTunesDB

 

guint64 id;

A 64 bit id value for the iTunesDB

 

gint32 tzoffset;

offset in seconds from UTC

 

gint32 reserved_int2;

Reserved for future use

 

Itdb_iTunesDB_Private *priv;

Private data

 

gpointer reserved2;

Reserved for future use

 

guint64 usertype;

For use by application

 

gpointer userdata;

For use by application

 

ItdbUserDataDuplicateFunc userdata_duplicate;

A function to duplicate userdata

 

ItdbUserDataDestroyFunc userdata_destroy;

A function to free userdata

 

Itdb_iTunesDB_Private

typedef struct {
    GList *mhsd5_playlists;
    guint16 platform;
    guint16 unk_0x22;
    guint64 id_0x24;
    guint16 lang;
    guint64 pid;
    gint32 unk_0x50;
    gint32 unk_0x54;
    gint16 audio_language;
    gint16 subtitle_language;
    gint16 unk_0xa4;
    gint16 unk_0xa6;
    gint16 unk_0xa8;
    gchar *genius_cuid;
} Itdb_iTunesDB_Private;


enum ItdbFileError

Error codes for iTunesDB file

Members

ITDB_FILE_ERROR_SEEK

file corrupt: illegal seek occurred

 

ITDB_FILE_ERROR_CORRUPT

file corrupt

 

ITDB_FILE_ERROR_NOTFOUND

file not found

 

ITDB_FILE_ERROR_RENAME

file could not be renamed

 

ITDB_FILE_ERROR_ITDB_CORRUPT

iTunesDB in memory corrupt