Foreign.Libcdio.CdText

Metadata is stored in a binary format both library-internally and on the disc. Most audio archivists will recognize it as "those information fields in a CUE file" (though there are other formats as well), and casual listeners will recognize it as the scrolling text that you're always happy to see, on the rare times your music player shows it. Little-used and even-less-known, however, is that a single disc can theoretically contain metadata in up to eight different languages; because of the complexity that introduces, no unifying datatype is provided in favour of a function-based interface.

cdtext.h

Defines

• MIN_CDTEXT_FIELD (removed; identical to minBound :: Field)
• MAX_CDTEXT_FIELD (removed; identical to maxBound :: Field)

Types

• cdtext_field_t -> Field

  • CDTEXT_FIELD_INVALID (removed; handled via Nothing)

• cdtext_genre_t -> Genre

  • CDTEXT_GENRE_UNUSED (removed; handled via Nothing)

• cdtext_lang_t -> Language

  • CDTEXT_LANGUAGE_UNKNOWN -> UnknownLanguage

    • Before libcdio 2.1.0: (often effectively removed; handled via Nothing)
  • CDTEXT_LANGUAGE_INVALID (removed; handled via Nothing)
  • CDTEXT_LANGUAGE_BLOCK_UNUSED (removed; handled via Nothing)
• cdtext_t (removed; merged into Cdio objects)

Symbols

• cdtext_data_init -> cdTextDataInit
• cdtext_destroy (removed; handled via the garbage collector)
• cdtext_field2str -> fieldString
• cdtext_genre2str -> genreString
• cdtext_get (removed; type conversion makes it identical to cdtext_get_const)
• cdtext_get_const -> cdTextGet
• cdtext_get_first_track -> firstTrack
• cdtext_get_genre -> genre
• cdtext_get_language -> language
• cdtext_get_last_track -> lastTrack
• cdtext_init (removed; internal function without much external occasion)
• cdtext_lang2str -> languageString
• cdtext_list_languages -> listLanguages
• cdtext_list_languages_v2 -> listAllLanguages
• cdtext_select_language -> selectLanguage
• cdtext_set (removed; primarily intended for internal use, and is more limited than would be expected)
• cdtext_set_language_index -> selectLanguageIndex
• cdtext_str2lang -> parseLanguage

Sound.Libcdio.Read.CdText

While similar functionality is provided, the Sound.Libcdio.Read.CdText is written as a separate monadic interface rather than in the Cdio-bound style used here.

• cdTextDataInit -> parseCdText
• cdTextGet -> discId, snd genre, and info
• genre -> fst genre
• listAllLanguages -> languages
• listLanguages (removed; obsolete and imprecise)
• selectLanguage -> withLanguage
• selectLanguageIndex -> withIndex

Types

data Cdio

A particular disc reading/writing device, along with the data contained on the loaded disc. Note well that this is always a mutable object, and is not thread-safe; moreover, any function this is passed to may wind up silently modifying the data.

data Field

Constructors

Title

Performer

Songwriter

Composer

Message

Arranger

Isrc

UpcEan

GenreName

DiscId

Instances

Bounded Field

Defined in Foreign.Libcdio.Types.Enums

Methods

minBound :: Field

maxBound :: Field

Enum Field

Defined in Foreign.Libcdio.Types.Enums

Methods

succ :: Field -> Field

pred :: Field -> Field

toEnum :: Int -> Field

fromEnum :: Field -> Int

enumFrom :: Field -> [Field]

enumFromThen :: Field -> Field -> [Field]

enumFromTo :: Field -> Field -> [Field]

enumFromThenTo :: Field -> Field -> Field -> [Field]

Eq Field

Defined in Foreign.Libcdio.Types.Enums

Methods

(==) :: Field -> Field -> Bool

(/=) :: Field -> Field -> Bool

Ord Field

Defined in Foreign.Libcdio.Types.Enums

Methods

compare :: Field -> Field -> Ordering

(<) :: Field -> Field -> Bool

(<=) :: Field -> Field -> Bool

(>) :: Field -> Field -> Bool

(>=) :: Field -> Field -> Bool

max :: Field -> Field -> Field

min :: Field -> Field -> Field

Read Field

Defined in Foreign.Libcdio.Types.Enums

Methods

readsPrec :: Int -> ReadS Field

readList :: ReadS [Field]

readPrec :: ReadPrec Field

readListPrec :: ReadPrec [Field]

Show Field

Defined in Foreign.Libcdio.Types.Enums

Methods

showsPrec :: Int -> Field -> ShowS

show :: Field -> String

showList :: [Field] -> ShowS

data Genre

Genres recognized in the CD Text standard.

Constructors

Undefined

AdultContemporary

AltRock

Childrens

Classic

ChristianContemporary

Country

Dance

EasyListening

Erotic

Folk

Gospel

HipHop

Jazz

LatinMusic

Musical

NewAge

Opera

Operetta

Pop

Rap

Reggae

Rock

RhythmAndBlues

SoundEffects

Soundtrack

SpokenWord

WorldMusic

Instances

Bounded Genre

Defined in Foreign.Libcdio.Types.Enums

Methods

minBound :: Genre

maxBound :: Genre

Enum Genre

Defined in Foreign.Libcdio.Types.Enums

Methods

succ :: Genre -> Genre

pred :: Genre -> Genre

toEnum :: Int -> Genre

fromEnum :: Genre -> Int

enumFrom :: Genre -> [Genre]

enumFromThen :: Genre -> Genre -> [Genre]

enumFromTo :: Genre -> Genre -> [Genre]

enumFromThenTo :: Genre -> Genre -> Genre -> [Genre]

Eq Genre

Defined in Foreign.Libcdio.Types.Enums

Methods

(==) :: Genre -> Genre -> Bool

(/=) :: Genre -> Genre -> Bool

Ord Genre

Defined in Foreign.Libcdio.Types.Enums

Methods

compare :: Genre -> Genre -> Ordering

(<) :: Genre -> Genre -> Bool

(<=) :: Genre -> Genre -> Bool

(>) :: Genre -> Genre -> Bool

(>=) :: Genre -> Genre -> Bool

max :: Genre -> Genre -> Genre

min :: Genre -> Genre -> Genre

Read Genre

Defined in Foreign.Libcdio.Types.Enums

Methods

readsPrec :: Int -> ReadS Genre

readList :: ReadS [Genre]

readPrec :: ReadPrec Genre

readListPrec :: ReadPrec [Genre]

Show Genre

Defined in Foreign.Libcdio.Types.Enums

Methods

showsPrec :: Int -> Genre -> ShowS

show :: Genre -> String

showList :: [Genre] -> ShowS

data Language

Written languages recognized in the CD Text standard.

Constructors

UnknownLanguage

Albanian

Breton

Catalan

Croatian

Welsh

Czech

Danish

German

English

Spanish

Esperanto

Estonian

Basque

Faroese

French

Frisian

Irish

Gaelic

Galician

Icelandic

Italian

Lappish

Latin

Latvian

Luxembourgian

Lithuanian

Hungarian

Maltese

Dutch

Norwegian

Occitan

Polish

Portuguese

Romanian

Romansh

Serbian

Slovak

Slovenian

Finnish

Swedish

Turkish

Flemish

Wallon

Zulu

Vietnamese

Uzbek

Urdu

Ukrainian

Thai

Telugu

Tatar

Tamil

Tadzhik

Swahili

SrananTongo

Somali

Sinhalese

Shona

SerboCroatian

Ruthenian

Russian

Quechua

Pushtu

Punjabi

Persian

Papamiento

Oriya

Nepali

Ndebele

Marathi

Moldavian

Malaysian

Malagasay

Macedonian

Laotian

Korean

Khmer

Kazakh

Kannada

Japanese

Indonesian

Hindi

Hebrew

Hausa

Gurani

Gujurati

Greek

Georgian

Fulani

Dari

Churash

Chinese

Burmese

Bulgarian

Bengali

Bielorussian

Bambora

Azerbaijani

Assamese

Armenian

Arabic

Amharic

Instances

Bounded Language

Defined in Foreign.Libcdio.Types.Enums

Methods

minBound :: Language

maxBound :: Language

Enum Language

Defined in Foreign.Libcdio.Types.Enums

Methods

succ :: Language -> Language

pred :: Language -> Language

toEnum :: Int -> Language

fromEnum :: Language -> Int

enumFrom :: Language -> [Language]

enumFromThen :: Language -> Language -> [Language]

enumFromTo :: Language -> Language -> [Language]

enumFromThenTo :: Language -> Language -> Language -> [Language]

Eq Language

Defined in Foreign.Libcdio.Types.Enums

Methods

(==) :: Language -> Language -> Bool

(/=) :: Language -> Language -> Bool

Ord Language

Defined in Foreign.Libcdio.Types.Enums

Methods

compare :: Language -> Language -> Ordering

(<) :: Language -> Language -> Bool

(<=) :: Language -> Language -> Bool

(>) :: Language -> Language -> Bool

(>=) :: Language -> Language -> Bool

max :: Language -> Language -> Language

min :: Language -> Language -> Language

Read Language

Defined in Foreign.Libcdio.Types.Enums

Methods

readsPrec :: Int -> ReadS Language

readList :: ReadS [Language]

readPrec :: ReadPrec Language

readListPrec :: ReadPrec [Language]

Show Language

Defined in Foreign.Libcdio.Types.Enums

Methods

showsPrec :: Int -> Language -> ShowS

show :: Language -> String

showList :: [Language] -> ShowS

Description

fieldString :: Field -> String

Describe the type of data in a human-readable manner, as opposed to the machine representation returned by the Show instance.

languageString :: Language -> String

Return a canonical English name of the given language, as opposed to the machine representation returned by the Show instance.

parseLanguage :: String -> Maybe Language

Transform a string returned by languageString back into its Language representation.

Before libcdio 2.1.0: Always returns Nothing

genreString :: Genre -> String

Return a canonical English name of the given genre, as opposed to the machine representation returned by the Show instance.

Management

cdTextDataInit :: ByteString -> IO (Maybe Cdio)

Read binary CD-TEXT data into a structured datatype.

Note that binary CdText dumps will frequently include four bytes at the beginning indicating the size of the file; this implementation expects that those bytes are not included. If your dump does include them, drop 4 before passing the ByteString to this function.

Before libcdio 0.94: Always returns Nothing

listLanguages :: Cdio -> IO [Language]

Retrieve the languages included in the disc metadata. Note that this does not save the index position or any duplicate language blocks (if that is desired, see listAllLanguages instead).

listAllLanguages :: Cdio -> IO [Maybe Language]

Retrieve the languages included in the disc metadata, in the order they occur, and respecting any empty language blocks if there's a valid language after them (empty blocks at the end are cleaned away).

Before libcdio 2.1.0: Acts as listLanguages

selectLanguage :: Cdio -> Language -> IO Bool

Try to set the data associated with the given language as active for future calls to cdTextGet and similar. If passed UnknownLanguage or the CDTEXT does not provide the one requested, selects the first (default) data set instead, and returns False.

selectLanguageIndex :: Cdio -> Word -> IO Bool

Select the language at the given index of listAllLanguages for future data retrieval. If the index is out of bounds or corresponds to a Nothing in listAllLanguages, the first (default) data set is selected instead and 'False is returned.

Access

cdTextGet :: Cdio -> Field -> Maybe Track -> IO (Maybe String)

Attempt to retrieve the value of a given field from the disc (if Nothing) or track (if Just) metadata, in the currently-active language. Note that GenreName and DiscId will always refer to the disc-level data.

genre :: Cdio -> IO (Maybe Genre)

The machine-readable genre describing the music on this disc. For any associated human-readable name or subgenre, use cdTextGet c GenreName Nothing.

language :: Cdio -> IO (Maybe Language)

Indicate which language results will (currently) be returned in. See selectLanguage to change this.

firstTrack :: Cdio -> IO (Maybe Track)

The earliest track with any associated metadata in the current language. Note that this may differ from minTrack.

lastTrack :: Cdio -> IO (Maybe Track)

The final track with any associated metadata in the current language. Note that this may differ from maxTrack.