Sequencepublic 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 {@link Sequencer} object. Specifically, the
Sequence contains timing
information and one or more tracks. Each {@link Track 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
{@link MidiSystem}. A sequence can also be built from scratch by adding new
Tracks to an empty Sequence, and adding
{@link MidiEvent} objects to these Tracks. |
| Fields Summary |
|---|
| public static final float | PPQThe tempo-based timing type, for which the resolution is expressed in pulses (ticks) per quarter note. | | public static final float | SMPTE_24The SMPTE-based timing type with 24 frames per second (resolution is expressed in ticks per frame). | | public static final float | SMPTE_25The SMPTE-based timing type with 25 frames per second (resolution is expressed in ticks per frame). | | public static final float | SMPTE_30DROPThe SMPTE-based timing type with 29.97 frames per second (resolution is expressed in ticks per frame). | | public static final float | SMPTE_30The SMPTE-based timing type with 30 frames per second (resolution is expressed in ticks per frame). | | protected float | divisionTypeThe timing division type of the sequence. | | protected int | resolutionThe timing resolution of the sequence. | | protected Vector | tracksThe MIDI tracks in this sequence. |
| Constructors Summary |
|---|
public Sequence(float divisionType, int resolution)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 {@link #createTrack}
and {@link #deleteTrack}.
if (divisionType == PPQ)
this.divisionType = PPQ;
else if (divisionType == SMPTE_24)
this.divisionType = SMPTE_24;
else if (divisionType == SMPTE_25)
this.divisionType = SMPTE_25;
else if (divisionType == SMPTE_30DROP)
this.divisionType = SMPTE_30DROP;
else if (divisionType == SMPTE_30)
this.divisionType = SMPTE_30;
else throw new InvalidMidiDataException("Unsupported division type: " + divisionType);
this.resolution = resolution;
| public Sequence(float divisionType, int resolution, int numTracks)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 {@link #getTracks}
method. Additional tracks may be added, or existing tracks removed,
using {@link #createTrack} and {@link #deleteTrack}.
if (divisionType == PPQ)
this.divisionType = PPQ;
else if (divisionType == SMPTE_24)
this.divisionType = SMPTE_24;
else if (divisionType == SMPTE_25)
this.divisionType = SMPTE_25;
else if (divisionType == SMPTE_30DROP)
this.divisionType = SMPTE_30DROP;
else if (divisionType == SMPTE_30)
this.divisionType = SMPTE_30;
else throw new InvalidMidiDataException("Unsupported division type: " + divisionType);
this.resolution = resolution;
for (int i = 0; i < numTracks; i++) {
tracks.addElement(new Track());
}
|
| Methods Summary |
|---|
| public javax.sound.midi.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 {@link #getTracks}. Tracks may be
removed from the sequence using {@link #deleteTrack}.
Track track = new Track();
tracks.addElement(track);
return track;
| | public boolean | deleteTrack(javax.sound.midi.Track track)Removes the specified track from the sequence.
synchronized(tracks) {
return tracks.removeElement(track);
}
| | public float | getDivisionType()Obtains the timing division type for this sequence.
return divisionType;
| | public long | getMicrosecondLength()Obtains the duration of this sequence, expressed in microseconds.
return com.sun.media.sound.MidiUtils.tick2microsecond(this, getTickLength(), null);
| | public javax.sound.midi.Patch[] | getPatchList()Obtains a list of patches referenced in this sequence.
This patch list may be used to load the required
{@link Instrument} objects
into a {@link Synthesizer}.
// $$kk: 04.09.99: need to implement!!
return new Patch[0];
| | 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.
return resolution;
| | public long | getTickLength()Obtains the duration of this sequence, expressed in MIDI ticks.
long length = 0;
synchronized(tracks) {
for(int i=0; i<tracks.size(); i++ ) {
long temp = ((Track)tracks.elementAt(i)).ticks();
if( temp>length ) {
length = temp;
}
}
return length;
}
| | public javax.sound.midi.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.
return (Track[]) tracks.toArray(new Track[tracks.size()]);
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