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:

• Sequencer.setSequence(java.io.InputStream stream)
• Sequencer.setSequence(Sequence sequence)
• Track.add(MidiEvent)
• MidiFileFormat

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 Object

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

Modifier and Type	Method	Description
protected Object	clone()	Creates and returns a copy of this object.
boolean	equals(Object obj)	Indicates whether some other object is "equal to" this one.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
final Class<?>	getClass()	Returns the runtime class of this Object.
int	hashCode()	Returns a hash code value for this object.
final void	notify()	Wakes up a single thread that is waiting on this object's monitor.
final void	notifyAll()	Wakes up all threads that are waiting on this object's monitor.
String	toString()	Returns a string representation of the object.
final void	wait()	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
final void	wait(long timeoutMillis)	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
final void	wait(long timeoutMillis, int nanos)	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Field Details

PPQ

public static final float PPQ

The tempo-based timing type, for which the resolution is expressed in pulses (ticks) per quarter note.

See Also:

• Sequence(float, int)
• Constant Field Values

SMPTE_24

public static final float SMPTE_24

The SMPTE-based timing type with 24 frames per second (resolution is expressed in ticks per frame).

See Also:

• Sequence(float, int)
• Constant Field Values

SMPTE_25

public static final float SMPTE_25

The SMPTE-based timing type with 25 frames per second (resolution is expressed in ticks per frame).

See Also:

• Sequence(float, int)
• Constant Field Values

SMPTE_30DROP

public static final float SMPTE_30DROP

The SMPTE-based timing type with 29.97 frames per second (resolution is expressed in ticks per frame).

See Also:

• Sequence(float, int)
• Constant Field Values

SMPTE_30

public static final float SMPTE_30

The SMPTE-based timing type with 30 frames per second (resolution is expressed in ticks per frame).

See Also:

• Sequence(float, int)
• Constant Field Values

divisionType

protected float divisionType

The timing division type of the sequence.

See Also:

• PPQ
• SMPTE_24
• SMPTE_25
• SMPTE_30DROP
• SMPTE_30
• getDivisionType()

resolution

protected int resolution

The timing resolution of the sequence.

See Also:

• getResolution()

tracks

protected Vector<Track> tracks

The MIDI tracks in this sequence.

See Also:

• getTracks()

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 SMPTE 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(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:

• PPQ
• SMPTE_24
• SMPTE_25
• SMPTE_30DROP
• SMPTE_30
• getDivisionType()
• getResolution()
• getTracks()

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 SMPTE 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(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:

• PPQ
• SMPTE_24
• SMPTE_25
• SMPTE_30DROP
• SMPTE_30
• getDivisionType()
• getResolution()

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:

• PPQ
• SMPTE_24
• SMPTE_25
• SMPTE_30DROP
• SMPTE_30
• Sequence(float, int)
• MidiFileFormat.getDivisionType()

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 SMPTE timing, the resolution is specified in ticks per frame.

Returns:

the number of ticks per beat (PPQ) or per frame (SMPTE)

See Also:

• getDivisionType()
• Sequence(float, int)
• MidiFileFormat.getResolution()

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(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:

• createTrack()
• getTracks()

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:

• createTrack()
• deleteTrack(Track)

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:

• getMicrosecondLength()

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:

• Synthesizer.loadInstruments(Soundbank, Patch[])