Class MIDI::Sequence
In: lib/midilib/sequence.rb
Parent: Object

A MIDI::Sequence contains MIDI::Track objects.

Methods

beats_per_minute   bpm   each   get_measures   length_to_delta   name   name=   new   note_to_delta   note_to_length   read   tempo   time_signature   write  

Included Modules

Enumerable

Constants

UNNAMED = 'Unnamed Sequence'
DEFAULT_TEMPO = 120
NOTE_TO_LENGTH = { 'whole' => 4.0, 'half' => 2.0, 'quarter' => 1.0, 'eighth' => 0.5, '8th' => 0.5, 'sixteenth' => 0.25, '16th' => 0.25, 'thirty second' => 0.125, 'thirtysecond' => 0.125, '32nd' => 0.125, 'sixty fourth' => 0.0625, 'sixtyfourth' => 0.0625, '64th' => 0.0625

Attributes

clocks  [RW] 
denom  [RW] 
format  [RW]  The MIDI file format (0, 1, or 2)
numer  [RW] 
ppqn  [RW]  Pulses (i.e. clocks) Per Quarter Note resolution for the sequence
qnotes  [RW] 
reader_class  [RW]  The class to use for reading MIDI from a stream. The default is MIDI::IO::SeqReader. You can change this at any time.
tracks  [RW]  Array with all tracks for the sequence
writer_class  [RW]  The class to use for writeing MIDI from a stream. The default is MIDI::IO::SeqWriter. You can change this at any time.

Public Class methods

Public Instance methods

beats_per_minute()

Returns the song tempo in beats per minute.

bpm()

Alias for beats_per_minute

each( {|track| ...}

Iterates over the tracks.

get_measures()

Returns a Measures object, which is an array container for all measures in the sequence

length_to_delta(length)

Translates length (a multiple of a quarter note) into a delta time. For example, 1 is a quarter note, 1.0/32.0 is a 32nd note, 1.5 is a dotted quarter, etc. Be aware when using division; 1/32 is zero due to integer mathematics and rounding. Use floating-point numbers like 1.0 and 32.0. This method always returns an integer.

See also note_to_delta and note_to_length.

name()

Returns the name of the first track (track zero). If there are no tracks, returns UNNAMED.

name=(name)

Hands the name to the first track. Does nothing if there are no tracks.

note_to_delta(name)

Given a note length name like "whole", "dotted quarter", or "8th triplet", return the length of that note in quarter notes as a delta time.

note_to_length(name)

Given a note length name like "whole", "dotted quarter", or "8th triplet", return the length of that note in quarter notes as a floating-point number, suitable for use as an argument to length_to_delta.

Legal names are any value in NOTE_TO_LENGTH, optionally prefixed by "dotted_" and/or suffixed by "_triplet". So, for example, "dotted_quarter_triplet" returns the length of a dotted quarter-note triplet and "32nd" returns 1/32.

tempo()

Alias for beats_per_minute

[Validate]