javax.sound.midi.Sequencer |
A hardware or software device that plays back a MIDI
is known as a sequencer.
A MIDI sequence contains lists of time-stamped MIDI data, such as
might be read from a standard MIDI file. Most
sequencers also provide functions for creating and editing sequences.
sequence
The Sequencer
interface includes methods for the following
basic MIDI sequencer operations:
Sequencer
has access to:
Nested Classes | |||||||||||
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Sequencer.SyncMode | A SyncMode object represents one of the ways in which
a MIDI sequencer's notion of time can be synchronized with a master
or slave device. |
Constants | |||||||||||
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int | LOOP_CONTINUOUSLY | A value indicating that looping should continue indefinitely rather than complete after a specific number of loops. |
Public Methods | |||||||||||
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Registers a controller event listener to receive notification
whenever the sequencer processes a control-change event of the
requested type or types.
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Registers a meta-event listener to receive
notification whenever a meta-event is encountered in the sequence
and processed by the sequencer.
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Obtains the number of repetitions for
playback.
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Obtains the end position of the loop,
in MIDI ticks.
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Obtains the start position of the loop,
in MIDI ticks.
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Obtains the current master synchronization mode for this sequencer.
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Obtains the set of master synchronization modes supported by this
sequencer.
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Obtains the length of the current sequence, expressed in microseconds,
or 0 if no sequence is set.
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Obtains the current position in the sequence, expressed in
microseconds.
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Obtains the sequence on which the Sequencer is currently operating.
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Obtains the current slave synchronization mode for this sequencer.
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Obtains the set of slave synchronization modes supported by the sequencer.
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Returns the current tempo factor for the sequencer.
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Obtains the current tempo, expressed in beats per minute.
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Obtains the current tempo, expressed in microseconds per quarter
note.
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Obtains the length of the current sequence, expressed in MIDI ticks,
or 0 if no sequence is set.
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Obtains the current position in the sequence, expressed in MIDI
ticks.
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Obtains the current mute state for a track.
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Obtains the current solo state for a track.
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Indicates whether the Sequencer is currently recording.
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Indicates whether the Sequencer is currently running.
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Disables recording to the specified track.
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Prepares the specified track for recording events received on a particular channel.
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Removes a controller event listener's interest in one or more
types of controller event.
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Removes the specified meta-event listener from this sequencer's
list of registered listeners, if in fact the listener is registered.
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Sets the number of repetitions of the loop for
playback.
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Sets the last MIDI tick that will be played in
the loop.
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Sets the first MIDI tick that will be
played in the loop.
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Sets the source of timing information used by this sequencer.
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Sets the current position in the sequence, expressed in microseconds
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Sets the current sequence on which the sequencer operates.
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Sets the current sequence on which the sequencer operates.
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Sets the slave synchronization mode for the sequencer.
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Scales the sequencer's actual playback tempo by the factor provided.
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Sets the tempo in beats per minute.
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Sets the tempo in microseconds per quarter note.
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Sets the current sequencer position in MIDI ticks
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Sets the mute state for a track.
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Sets the solo state for a track.
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Starts playback of the MIDI data in the currently
loaded sequence.
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Starts recording and playback of MIDI data.
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Stops recording, if active, and playback of the currently loaded sequence,
if any.
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Stops recording, if active.
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[Expand]
Inherited Methods | |||||||||||
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A value indicating that looping should continue indefinitely rather than complete after a specific number of loops.
Registers a controller event listener to receive notification
whenever the sequencer processes a control-change event of the
requested type or types. The types are specified by the
controllers
argument, which should contain an array of
MIDI controller numbers. (Each number should be between 0 and 127,
inclusive. See the MIDI 1.0 Specification for the numbers that
correspond to various types of controllers.)
The returned array contains the MIDI controller numbers for which the listener will now receive events. Some sequencers might not support controller event notification, in which case the array has a length of 0. Other sequencers might support notification for some controllers but not all. This method may be invoked repeatedly. Each time, the returned array indicates all the controllers that the listener will be notified about, not only the controllers requested in that particular invocation.
listener | the controller event listener to add to the list of registered listeners |
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controllers | the MIDI controller numbers for which change notification is requested |
Registers a meta-event listener to receive notification whenever a meta-event is encountered in the sequence and processed by the sequencer. This method can fail if, for instance,this class of sequencer does not support meta-event notification.
listener | listener to add |
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true
if the listener was successfully added,
otherwise false
Obtains the number of repetitions for playback.
Obtains the end position of the loop, in MIDI ticks.
Obtains the start position of the loop, in MIDI ticks.
Obtains the current master synchronization mode for this sequencer.
Obtains the set of master synchronization modes supported by this sequencer.
Obtains the length of the current sequence, expressed in microseconds, or 0 if no sequence is set.
Obtains the current position in the sequence, expressed in microseconds.
Obtains the sequence on which the Sequencer is currently operating.
This method can be called even if the
Sequencer
is closed.
null
if no sequence is currently set.
Obtains the current slave synchronization mode for this sequencer.
Obtains the set of slave synchronization modes supported by the sequencer.
Returns the current tempo factor for the sequencer. The default is 1.0.
Obtains the current tempo, expressed in beats per minute. The actual tempo of playback is the product of the returned value and the tempo factor.
Obtains the current tempo, expressed in microseconds per quarter note. The actual tempo of playback is the product of the returned value and the tempo factor.
Obtains the length of the current sequence, expressed in MIDI ticks, or 0 if no sequence is set.
Obtains the current position in the sequence, expressed in MIDI
ticks. (The duration of a tick in seconds is determined both by
the tempo and by the timing resolution stored in the
.)Sequence
Obtains the current mute state for a track. The default mute state for all tracks which have not been muted is false. In any case where the specified track has not been muted, this method should return false. This applies if the sequencer does not support muting of tracks, and if the specified track index is not valid.
track | the track number. Tracks in the current sequence are numbered from 0 to the number of tracks in the sequence minus 1. |
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true
if muted, false
if not.
Obtains the current solo state for a track. The default mute state for all tracks which have not been solo'd is false. In any case where the specified track has not been solo'd, this method should return false. This applies if the sequencer does not support soloing of tracks, and if the specified track index is not valid.
track | the track number. Tracks in the current sequence are numbered from 0 to the number of tracks in the sequence minus 1. |
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true
if solo'd, false
if not.
Indicates whether the Sequencer is currently recording. The default is false
.
The Sequencer begins recording when
is called,
and then returns startRecording()
true
until
or stop()
is called.stopRecording()
true
if the Sequencer is recording, otherwise false
Indicates whether the Sequencer is currently running. The default is false
.
The Sequencer starts running when either
or start()
is called. startRecording()
isRunning
then returns true
until playback of the
sequence completes or
is called.stop()
true
if the Sequencer is running, otherwise false
Disables recording to the specified track. Events will no longer be recorded into this track.
track | the track to disable for recording, or null to disable
recording for all tracks.
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Prepares the specified track for recording events received on a particular channel. Once enabled, a track will receive events when recording is active.
track | the track to which events will be recorded |
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channel | the channel on which events will be received. If -1 is specified for the channel value, the track will receive data from all channels. |
IllegalArgumentException | thrown if the track is not part of the current sequence. |
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Removes a controller event listener's interest in one or more
types of controller event. The controllers
argument
is an array of MIDI numbers corresponding to the controllers for
which the listener should no longer receive change notifications.
To completely remove this listener from the list of registered
listeners, pass in null
for controllers
.
The returned array contains the MIDI controller
numbers for which the listener will now receive events. The
array has a length of 0 if the listener will not receive
change notifications for any controllers.
listener | old listener |
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controllers | the MIDI controller numbers for which change
notification should be cancelled, or null to cancel
for all controllers |
Removes the specified meta-event listener from this sequencer's list of registered listeners, if in fact the listener is registered.
listener | the meta-event listener to remove |
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Sets the number of repetitions of the loop for
playback.
When the playback position reaches the loop end point,
it will loop back to the loop start point
count
times, after which playback will
continue to play to the end of the sequence.
If the current position when this method is invoked is greater than the loop end point, playback continues to the end of the sequence without looping, unless the loop end point is changed subsequently.
A count
value of 0 disables looping:
playback will continue at the loop end point, and it
will not loop back to the loop start point.
This is a sequencer's default.
If playback is stopped during looping, the current loop status is cleared; subsequent start requests are not affected by an interrupted loop operation.
count | the number of times playback should
loop back from the loop's end position
to the loop's start position, or
to indicate that looping should
continue until interrupted |
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IllegalArgumentException | if count is
negative and not equal to LOOP_CONTINUOUSLY |
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Sets the last MIDI tick that will be played in the loop. If the loop count is 0, the loop end point has no effect and playback continues to play when reaching the loop end point.
A value of -1 for the ending point indicates the last tick of the sequence. Otherwise, the ending point must be greater than or equal to the starting point, and it must fall within the size of the loaded sequence.
A sequencer's loop end point defaults to -1, meaning the end of the sequence.
tick | the loop's ending position, in MIDI ticks (zero-based), or -1 to indicate the final tick |
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IllegalArgumentException | if the requested loop point cannot be set, usually because it falls outside the sequence's duration or because the ending point is before the starting point |
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Sets the first MIDI tick that will be played in the loop. If the loop count is greater than 0, playback will jump to this point when reaching the loop end point.
A value of 0 for the starting point means the beginning of the loaded sequence. The starting point must be lower than or equal to the ending point, and it must fall within the size of the loaded sequence.
A sequencer's loop start point defaults to start of the sequence.
tick | the loop's starting position, in MIDI ticks (zero-based) |
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IllegalArgumentException | if the requested loop start point cannot be set, usually because it falls outside the sequence's duration or because the start point is after the end point |
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Sets the source of timing information used by this sequencer.
The sequencer synchronizes to the master, which is the internal clock,
MIDI clock, or MIDI time code, depending on the value of
sync
. The sync
argument must be one
of the supported modes, as returned by
.getMasterSyncModes()
sync | the desired master synchronization mode |
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Sets the current position in the sequence, expressed in microseconds
microseconds | desired position in microseconds |
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Sets the current sequence on which the sequencer operates. The stream must point to MIDI file data.
This method can be called even if the
Sequencer
is closed.
stream | stream containing MIDI file data. |
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IOException | if an I/O exception occurs during reading of the stream. |
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InvalidMidiDataException | if invalid data is encountered in the stream, or the stream is not supported. |
Sets the current sequence on which the sequencer operates.
This method can be called even if the
Sequencer
is closed.
sequence | the sequence to be loaded. |
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InvalidMidiDataException | if the sequence contains invalid MIDI data, or is not supported. |
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Sets the slave synchronization mode for the sequencer.
This indicates the type of timing information sent by the sequencer
to its receiver. The sync
argument must be one
of the supported modes, as returned by
.getSlaveSyncModes()
sync | the desired slave synchronization mode |
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Scales the sequencer's actual playback tempo by the factor provided.
The default is 1.0. A value of 1.0 represents the natural rate (the
tempo specified in the sequence), 2.0 means twice as fast, etc.
The tempo factor does not affect the values returned by
and getTempoInMPQ()
.
Those values indicate the tempo prior to scaling.
getTempoInBPM()
Note that the tempo factor cannot be adjusted when external
synchronization is used. In that situation,
setTempoFactor
always sets the tempo factor to 1.0.
factor | the requested tempo scalar |
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Sets the tempo in beats per minute. The actual tempo of playback is the product of the specified value and the tempo factor.
bpm | desired new tempo in beats per minute |
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Sets the tempo in microseconds per quarter note. The actual tempo of playback is the product of the specified value and the tempo factor.
mpq | desired new tempo in microseconds per quarter note. |
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Sets the current sequencer position in MIDI ticks
tick | the desired tick position |
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Sets the mute state for a track. This method may fail for a number
of reasons. For example, the track number specified may not be valid
for the current sequence, or the sequencer may not support this functionality.
An application which needs to verify whether this operation succeeded should
follow this call with a call to
.getTrackMute(int)
track | the track number. Tracks in the current sequence are numbered from 0 to the number of tracks in the sequence minus 1. |
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mute | the new mute state for the track. true implies the
track should be muted, false implies the track should be unmuted. |
Sets the solo state for a track. If solo
is true
only this track and other solo'd tracks will sound. If solo
is false
then only other solo'd tracks will sound, unless no
tracks are solo'd in which case all un-muted tracks will sound.
This method may fail for a number
of reasons. For example, the track number specified may not be valid
for the current sequence, or the sequencer may not support this functionality.
An application which needs to verify whether this operation succeeded should
follow this call with a call to
.getTrackSolo(int)
track | the track number. Tracks in the current sequence are numbered from 0 to the number of tracks in the sequence minus 1. |
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solo | the new solo state for the track. true implies the
track should be solo'd, false implies the track should not be solo'd. |
Starts playback of the MIDI data in the currently
loaded sequence.
Playback will begin from the current position.
If the playback position reaches the loop end point,
and the loop count is greater than 0, playback will
resume at the loop start point for the number of
repetitions set with setLoopCount
.
After that, or if the loop count is 0, playback will
continue to play to the end of the sequence.
The implementation ensures that the synthesizer is brought to a consistent state when jumping to the loop start point by sending appropriate controllers, pitch bend, and program change events.
IllegalStateException | if the Sequencer is
closed. |
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Starts recording and playback of MIDI data. Data is recorded to all enabled tracks, on the channel(s) for which they were enabled. Recording begins at the current position of the sequencer. Any events already in the track are overwritten for the duration of the recording session. Events from the currently loaded sequence, if any, are delivered to the sequencer's transmitter(s) along with messages received during recording.
Note that tracks are not by default enabled for recording. In order to record MIDI data, at least one track must be specifically enabled for recording.
IllegalStateException | if the Sequencer is
closed. |
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Stops recording, if active, and playback of the currently loaded sequence, if any.
IllegalStateException | if the Sequencer is
closed. |
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Stops recording, if active. Playback of the current sequence continues.
IllegalStateException | if the Sequencer is
closed. |
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