Module java.desktop
Package javax.sound.midi

Class Sequence

java.lang.Object
javax.sound.midi.Sequence
public class Sequence extends Object
A Sequence is a data structure containing musical information (often an entire song or composition) that can be played back by a Sequencer object. Specifically, the Sequence contains timing information and one or more tracks. Each track consists of a series of MIDI events (such as note-ons, note-offs, program changes, and meta-events). The sequence's timing information specifies the type of unit that is used to time-stamp the events in the sequence.

A Sequence can be created from a MIDI file by reading the file into an input stream and invoking one of the getSequence methods of MidiSystem. A sequence can also be built from scratch by adding new Tracks to an empty Sequence, and adding MidiEvent objects to these Tracks.

See Also:

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected float
    divisionType
    The timing division type of the sequence.
    static final float
    PPQ
    The tempo-based timing type, for which the resolution is expressed in pulses (ticks) per quarter note.
    protected int
    resolution
    The timing resolution of the sequence.
    static final float
    SMPTE_24
    The SMPTE-based timing type with 24 frames per second (resolution is expressed in ticks per frame).
    static final float
    SMPTE_25
    The SMPTE-based timing type with 25 frames per second (resolution is expressed in ticks per frame).
    static final float
    SMPTE_30
    The SMPTE-based timing type with 30 frames per second (resolution is expressed in ticks per frame).
    static final float
    SMPTE_30DROP
    The SMPTE-based timing type with 29.97 frames per second (resolution is expressed in ticks per frame).
    protected Vector<Track>
    tracks
    The MIDI tracks in this sequence.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Sequence(float divisionType, int resolution)
    Constructs a new MIDI sequence with the specified timing division type and timing resolution.
    Sequence(float divisionType, int resolution, int numTracks)
    Constructs a new MIDI sequence with the specified timing division type, timing resolution, and number of tracks.

  • Method Summary

    Modifier and Type
    Method
    Description
    Track
    createTrack()
    Creates a new, initially empty track as part of this sequence.
    boolean
    deleteTrack(Track track)
    Removes the specified track from the sequence.
    float
    getDivisionType()
    Obtains the timing division type for this sequence.
    long
    getMicrosecondLength()
    Obtains the duration of this sequence, expressed in microseconds.
    Patch[]
    getPatchList()
    Obtains a list of patches referenced in this sequence.
    int
    getResolution()
    Obtains the timing resolution for this sequence.
    long
    getTickLength()
    Obtains the duration of this sequence, expressed in MIDI ticks.
    Track[]
    getTracks()
    Obtains an array containing all the tracks in this sequence.

    Methods declared in class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

  • Constructor Details

    • Sequence

      public Sequence(float divisionType, int resolution) throws InvalidMidiDataException
      Constructs a new MIDI sequence with the specified timing division type and timing resolution. The division type must be one of the recognized MIDI timing types. For tempo-based timing, divisionType is PPQ (pulses per quarter note) and the resolution is specified in ticks per beat. For SMTPE timing, divisionType specifies the number of frames per second and the resolution is specified in ticks per frame. The sequence will contain no initial tracks. Tracks may be added to or removed from the sequence using createTrack() and deleteTrack(javax.sound.midi.Track).
      Parameters:
      divisionType - the timing division type (PPQ or one of the SMPTE types)
      resolution - the timing resolution
      Throws:
      InvalidMidiDataException - if divisionType is not valid
      See Also:

    • Sequence

      public Sequence(float divisionType, int resolution, int numTracks) throws InvalidMidiDataException
      Constructs a new MIDI sequence with the specified timing division type, timing resolution, and number of tracks. The division type must be one of the recognized MIDI timing types. For tempo-based timing, divisionType is PPQ (pulses per quarter note) and the resolution is specified in ticks per beat. For SMTPE timing, divisionType specifies the number of frames per second and the resolution is specified in ticks per frame. The sequence will be initialized with the number of tracks specified by numTracks. These tracks are initially empty (i.e. they contain only the meta-event End of Track). The tracks may be retrieved for editing using the getTracks() method. Additional tracks may be added, or existing tracks removed, using createTrack() and deleteTrack(javax.sound.midi.Track).
      Parameters:
      divisionType - the timing division type (PPQ or one of the SMPTE types)
      resolution - the timing resolution
      numTracks - the initial number of tracks in the sequence
      Throws:
      InvalidMidiDataException - if divisionType is not valid
      See Also:

  • Method Details

    • getDivisionType

      public float getDivisionType()
      Obtains the timing division type for this sequence.
      Returns:
      the division type (PPQ or one of the SMPTE types)
      See Also:

    • getResolution

      public int getResolution()
      Obtains the timing resolution for this sequence. If the sequence's division type is PPQ, the resolution is specified in ticks per beat. For SMTPE timing, the resolution is specified in ticks per frame.
      Returns:
      the number of ticks per beat (PPQ) or per frame (SMPTE)
      See Also:

    • createTrack

      public Track createTrack()
      Creates a new, initially empty track as part of this sequence. The track initially contains the meta-event End of Track. The newly created track is returned. All tracks in the sequence may be retrieved using getTracks(). Tracks may be removed from the sequence using deleteTrack(javax.sound.midi.Track).
      Returns:
      the newly created track

    • deleteTrack

      public boolean deleteTrack(Track track)
      Removes the specified track from the sequence.
      Parameters:
      track - the track to remove
      Returns:
      true if the track existed in the track and was removed, otherwise false
      See Also:

    • getTracks

      public Track[] getTracks()
      Obtains an array containing all the tracks in this sequence. If the sequence contains no tracks, an array of length 0 is returned.
      Returns:
      the array of tracks
      See Also:

    • getMicrosecondLength

      public long getMicrosecondLength()
      Obtains the duration of this sequence, expressed in microseconds.
      Returns:
      this sequence's duration in microseconds

    • getTickLength

      public long getTickLength()
      Obtains the duration of this sequence, expressed in MIDI ticks.
      Returns:
      this sequence's length in ticks
      See Also:

    • getPatchList

      public Patch[] getPatchList()
      Obtains a list of patches referenced in this sequence. This patch list may be used to load the required Instrument objects into a Synthesizer.
      Returns:
      an array of Patch objects used in this sequence
      See Also: