Portability	non-portable
Stability	experimental
Maintainer	bas@chordify.net, dreixel@chordify.net
Safe Haskell	Safe-Inferred

HarmTrace.Base.MusicTime

Contents

Datatypes
Functions
- Data access
- Type conversion and other utilities

Description

Summary: A set of types and classes for representing musical time, mainly (but not necessarily) in the context of recognising chords from an arbitrary audio source.

Synopsis

Datatypes

Types for representing Chords and their probabilities

type ChordAnnotation = [TimedData ProbChord]Source

A chord annotation consists of a list with chords and segment boundaries.

data ProbChordSeg Source

Clustering ProbChords in a collection of chords that share a key

Constructors

Segment
Fields segKey :: Key segChords :: [TimedData [ProbChord]]

Instances

Eq ProbChordSeg
Show ProbChordSeg

data ProbChord Source

Combines a ChordLabel with a probability.

Constructors

ProbChord
Fields chordLab :: ChordLabel prob :: NumData

Instances

Eq ProbChord
Show ProbChord

data ChordCand Source

A chord candidate: an intermediate datatype that matches shorthand, chord structure and root note (plus inversion)

Constructors

ChordCand
Fields originalRootCC :: Root inversionRootCC :: Root shorthardCC :: Shorthand chordStructCC :: ChordStruct

Instances

Eq ChordCand
Show ChordCand

Representing musical time

data TimedData a Source

A datatype that wraps around an (musical) datatype, adding information about the musical time to this datatype. Musical time is stored as a list of BarTime time stamps that can optionally be augmented with information about the Beat position of the particular time stamp inside the bar.

Constructors

TimedData
Fields getData :: a Returns the contained datatype getTimeStamps :: [BarTime] Returns the list of TimeStamps

Instances

Functor TimedData
Eq a => Eq (TimedData a)
Show a => Show (TimedData a)

data Beat Source

For now, we fix the number of available beats to four, because this is also hard-coded into the bar and beat-tracker.

Constructors

One
Two
Three
Four
NoBeat

Instances

Enum Beat
Eq Beat
Show Beat

data BarTime Source

Represents a musical time stamp, which is a NumData possibly augmented with a Beat denoting the position of the time stamp within a bar.

Constructors

BarTime NumData Beat
Time NumData

Instances

Eq BarTime
Ord BarTime
Show BarTime

type BarTimeTrackData = [BarTime]Source

type NumData = Double Source

A type synonym is defined for our main numerical representation, this allows us to easily change the precision.

Representing raw audio data

data AudioFeat Source

Groups the three types of VAMP plug-in data: ChordinoData, BarTimeTrackData, and KeyStrengthData. See for more information:

Constructors

AudioFeat
Fields getChroma :: ChordinoData getBeats :: BarTimeTrackData getKeys :: KeyStrengthData getAudioFeatId :: FilePath

type ChordinoData = [ChordinoLine]Source

data ChordinoLine Source

Represents two chroma features and a time stamp.

Constructors

ChordinoLine
Fields time :: NumData Returns the time stamp of the chroma features bass :: [NumData] Returns the bass chroma feature treb :: [NumData] Returns the treble chroma feature

Instances

Eq ChordinoLine
Show ChordinoLine

type KeyStrengthData = ChordinoData Source

type BeatTrackerData = [NumData]Source

type BeatChroma = TimedData [ChordinoLine]Source

type ChordStruct = [NumData]Source

A chord template is list of NumDatas

Functions

Data access

timedData :: a -> NumData -> NumData -> TimedData aSource

alternative TimedData constructor

timedDataBT :: a -> BarTime -> BarTime -> TimedData aSource

alternative TimedData constructor

getBarTime :: TimedData a -> BarTime Source

Returns the start time stamp

getBeat :: TimedData a -> Beat Source

Returns the start Beat

onset :: TimedData a -> NumData Source

Returns the onset time stamp

offset :: TimedData a -> NumData Source

Returns the offset time stamp

setData :: TimedData a -> b -> TimedData bSource

wraps a datatype in TimedData

Type conversion and other utilities

getBeatTrack :: BarTimeTrackData -> BeatTrackerData Source

Converts BarTimeTrackData into BeatTrackerData

concatTimedData :: a -> TimedData a -> TimedData a -> TimedData aSource

concatenates the BarTime timestamps of two TimedDatas and creates a new TimedData that stores the first argument.

nextBeat :: Beat -> Beat Source

returns the next beat, e.g. nextBeat Two = Three . Following the (current) definition of Beat, we still assume 4/4, in the future this function should also have the meter as an argument.

prevBeat :: Beat -> Beat Source

returns the previous Beat, similar to prevBeat.

returns the next beat, e.g. nextBeat Two = Three . Following the (current) definition of Beat, we still assume 4/4, in the future this function should also have the meter as an argument.

updateTPChord :: (ChordLabel -> ChordLabel) -> TimedData ProbChord -> TimedData ProbChord Source

Updates transforms ChordLabel wrapped in a ProbChord and TimedData

dropProb :: [TimedData ProbChord] -> [TimedData ChordLabel]Source

drops the probabilties paired with chordlabels (in a list of ProbChords) and returns a list of ChordLabels

dropTimed :: [TimedData a] -> [a]Source

drops the time (with or without Beat) information of a list Timed data structure

timeStamp :: BarTime -> NumData Source

Returns the NumData timestamp, given a BarTime

beat :: BarTime -> Beat Source

Returns the NumData timestamp, given a BarTime