Safe Haskell | Safe |
---|---|
Language | Haskell2010 |
MIDI-File Datatype
Taken from Haskore.
- data T = Cons Type Division [Track]
- data Division
- type Track = T ElapsedTime T
- data Type
- empty :: T
- type ElapsedTime = Integer
- fromElapsedTime :: ElapsedTime -> Integer
- toElapsedTime :: Integer -> ElapsedTime
- type Tempo = Int
- fromTempo :: Tempo -> Int
- toTempo :: Int -> Tempo
- explicitNoteOff :: T -> T
- implicitNoteOff :: T -> T
- getTracks :: T -> [Track]
- mergeTracks :: C time => Type -> [T time event] -> T time event
- mapTrack :: (Track -> Track) -> T -> T
- secondsFromTicks :: Division -> T ElapsedTime T -> T Rational T
- ticksPerQuarterNote :: Division -> Tempo
- showLines :: T -> String
- changeVelocity :: Double -> T -> T
- resampleTime :: Double -> T -> T
- showEvent :: T -> ShowS
- showTime :: ElapsedTime -> ShowS
- sortEvents :: T -> T
- progChangeBeforeSetTempo :: T -> T
Documentation
The datatypes for MIDI Files and MIDI Events
type Track = T ElapsedTime T Source
type ElapsedTime = Integer Source
explicitNoteOff :: T -> T Source
Convert all NoteOn p 0
to NoteOff p 64
.
The latter one is easier to process.
implicitNoteOff :: T -> T Source
Convert all NoteOff p 64
to NoteOn p 0
.
The latter one can be encoded more efficiently using the running status.
mergeTracks :: C time => Type -> [T time event] -> T time event Source
Merge all tracks into a single track according to the MIDI file type.
secondsFromTicks :: Division -> T ElapsedTime T -> T Rational T Source
Process and remove all SetTempo
events.
The result is an event list where the times are measured in seconds.
changeVelocity :: Double -> T -> T Source
Deprecated: only use this for debugging
A hack that changes the velocities by a rational factor.
resampleTime :: Double -> T -> T Source
Deprecated: only use this for debugging
Change the time base.
showTime :: ElapsedTime -> ShowS Source
Deprecated: only use this for debugging
sortEvents :: T -> T Source
Deprecated: only use this for debugging
Sort MIDI note events lexicographically. This is to make MIDI files unique and robust against changes in the computation. In principle Performance.merge should handle this but due to rounding errors in Float the order of note events still depends on some internal issues. The sample rate of MIDI events should be coarse enough to assert unique results.
progChangeBeforeSetTempo :: T -> T Source
Deprecated: only use this for debugging
Old versions of Haskore.Interface.MIDI.Write
wrote ProgramChange
and SetTempo
once at the beginning of a file in that order.
The current version supports multiple ProgramChange
s in a track and
thus a ProgramChange
is set immediately before a note.
Because of this a ProgramChange
is now always after a SetTempo
.
For checking equivalence with old MIDI files we can switch this back.