Codec.Audio.FLAC.StreamDecoder

The module contains a Haskell interface to FLAC stream decoder.

How to use this module

Just call the decodeFlac function with DecoderSettings, input and output file names. The decodeFlac function can produce vanilla WAVE and RF64.

Low-level details

The implementation uses the reference implementation of FLAC — libFLAC (C library) under the hood. This means you'll need at least version 1.3.0 of libFLAC (released 26 May 2013) installed for the binding to work.

The binding works with minimal overhead compared to pure C implementation. Decoding speed is equal to that of flac command line tool. Memory consumption is minimal and remains constant regardless of size of file to decode.

Documentation

data DecoderSettings

Parameters of stream decoder.

Constructors

DecoderSettings

Fields

• decoderMd5Checking :: !Bool

  If True, the decoder will compute the MD5 signature of the unencoded audio data while decoding and compare it to the signature from the STREAMINFO block. Default value: False.

• decoderWaveFormat :: !WaveFormat

  This specifies WAVE format in which to save the decoded file. You can choose between WaveVanilla and WaveRF64; choose the latter if uncompressed file is expected to be longer than 4 Gb. Default value: WaveVanilla.

Instances

Eq DecoderSettings

Methods

(==) :: DecoderSettings -> DecoderSettings -> Bool

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

Ord DecoderSettings

Methods

compare :: DecoderSettings -> DecoderSettings -> Ordering

(<) :: DecoderSettings -> DecoderSettings -> Bool

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

(>) :: DecoderSettings -> DecoderSettings -> Bool

(>=) :: DecoderSettings -> DecoderSettings -> Bool

max :: DecoderSettings -> DecoderSettings -> DecoderSettings

min :: DecoderSettings -> DecoderSettings -> DecoderSettings

Read DecoderSettings

Methods

readsPrec :: Int -> ReadS DecoderSettings

readList :: ReadS [DecoderSettings]

readPrec :: ReadPrec DecoderSettings

readListPrec :: ReadPrec [DecoderSettings]

Show DecoderSettings

Methods

showsPrec :: Int -> DecoderSettings -> ShowS

show :: DecoderSettings -> String

showList :: [DecoderSettings] -> ShowS

Default DecoderSettings

Methods

def :: DecoderSettings

data DecoderException

Exception that is thrown when decoding fails for some reason.

Constructors

DecoderInitFailed DecoderInitStatus

Decoder initialization failed.

DecoderFailed DecoderState

Decoder failed.

Instances

Eq DecoderException

Methods

(==) :: DecoderException -> DecoderException -> Bool

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

Read DecoderException

Methods

readsPrec :: Int -> ReadS DecoderException

readList :: ReadS [DecoderException]

readPrec :: ReadPrec DecoderException

readListPrec :: ReadPrec [DecoderException]

Show DecoderException

Methods

showsPrec :: Int -> DecoderException -> ShowS

show :: DecoderException -> String

showList :: [DecoderException] -> ShowS

Exception DecoderException

Methods

toException :: DecoderException -> SomeException

fromException :: SomeException -> Maybe DecoderException

displayException :: DecoderException -> String

data DecoderInitStatus

Status of decoder initialization process.

Constructors

DecoderInitStatusOK

Initialization was successful.

DecoderInitStatusUnsupportedContainer

The library was not compiled with support for the given container format.

DecoderInitStatusInvalidCallbacks

A required callback was not supplied.

DecoderInitStatusMemoryAllocationError

An error occurred allocating memory.

DecoderInitStatusErrorOpeningFile

fopen() failed.

DecoderInitStatusAlreadyInitialized

Initialization was attempted on already initialized decoder.

Instances

Bounded DecoderInitStatus

Methods

minBound :: DecoderInitStatus

maxBound :: DecoderInitStatus

Enum DecoderInitStatus

Methods

succ :: DecoderInitStatus -> DecoderInitStatus

pred :: DecoderInitStatus -> DecoderInitStatus

toEnum :: Int -> DecoderInitStatus

fromEnum :: DecoderInitStatus -> Int

enumFrom :: DecoderInitStatus -> [DecoderInitStatus]

enumFromThen :: DecoderInitStatus -> DecoderInitStatus -> [DecoderInitStatus]

enumFromTo :: DecoderInitStatus -> DecoderInitStatus -> [DecoderInitStatus]

enumFromThenTo :: DecoderInitStatus -> DecoderInitStatus -> DecoderInitStatus -> [DecoderInitStatus]

Eq DecoderInitStatus

Methods

(==) :: DecoderInitStatus -> DecoderInitStatus -> Bool

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

Ord DecoderInitStatus

Methods

compare :: DecoderInitStatus -> DecoderInitStatus -> Ordering

(<) :: DecoderInitStatus -> DecoderInitStatus -> Bool

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

(>) :: DecoderInitStatus -> DecoderInitStatus -> Bool

(>=) :: DecoderInitStatus -> DecoderInitStatus -> Bool

max :: DecoderInitStatus -> DecoderInitStatus -> DecoderInitStatus

min :: DecoderInitStatus -> DecoderInitStatus -> DecoderInitStatus

Read DecoderInitStatus

Methods

readsPrec :: Int -> ReadS DecoderInitStatus

readList :: ReadS [DecoderInitStatus]

readPrec :: ReadPrec DecoderInitStatus

readListPrec :: ReadPrec [DecoderInitStatus]

Show DecoderInitStatus

Methods

showsPrec :: Int -> DecoderInitStatus -> ShowS

show :: DecoderInitStatus -> String

showList :: [DecoderInitStatus] -> ShowS

data DecoderState

Enumeration of decoder states.

Constructors

DecoderStateSearchForMetadata

The decoder is ready to search for metadata.

DecoderStateReadMetadata

The decoder is ready to or is in the process of reading metadata.

DecoderStateSearchForFrameSync

The decoder is ready to or is in the process of searching for the frame sync code.

DecoderStateReadFrame

The decoder is ready to or is in the process of reading a frame.

DecoderStateEndOfStream

The decoder has reached the end of the stream.

DecoderStateOggError

An error occurred in the underlying Ogg layer.

DecoderStateSeekError

An error occurred while seeking. The decoder must be flushed or reset before decoding can continue.

DecoderStateAborted

The decoder was aborted by the read callback.

DecoderStateMemoryAllocationError

An error occurred allocating memory. The decoder is in an invalid state and can no longer be used.

DecoderStateUnititialized

The decoder is in the uninitialized state.

Instances

Bounded DecoderState

Methods

minBound :: DecoderState

maxBound :: DecoderState

Enum DecoderState

Methods

succ :: DecoderState -> DecoderState

pred :: DecoderState -> DecoderState

toEnum :: Int -> DecoderState

fromEnum :: DecoderState -> Int

enumFrom :: DecoderState -> [DecoderState]

enumFromThen :: DecoderState -> DecoderState -> [DecoderState]

enumFromTo :: DecoderState -> DecoderState -> [DecoderState]

enumFromThenTo :: DecoderState -> DecoderState -> DecoderState -> [DecoderState]

Eq DecoderState

Methods

(==) :: DecoderState -> DecoderState -> Bool

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

Ord DecoderState

Methods

compare :: DecoderState -> DecoderState -> Ordering

(<) :: DecoderState -> DecoderState -> Bool

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

(>) :: DecoderState -> DecoderState -> Bool

(>=) :: DecoderState -> DecoderState -> Bool

max :: DecoderState -> DecoderState -> DecoderState

min :: DecoderState -> DecoderState -> DecoderState

Read DecoderState

Methods

readsPrec :: Int -> ReadS DecoderState

readList :: ReadS [DecoderState]

readPrec :: ReadPrec DecoderState

readListPrec :: ReadPrec [DecoderState]

Show DecoderState

Methods

showsPrec :: Int -> DecoderState -> ShowS

show :: DecoderState -> String

showList :: [DecoderState] -> ShowS

decodeFlac

Arguments

:: MonadIO m

=> DecoderSettings

Decoder settings

-> FilePath

File to decode

-> FilePath

Where to save the resulting WAVE file

-> m ()

Decode a FLAC file to WAVE.

DecoderException is thrown when underlying FLAC decoder reports a problem.