MidiChannel object represents a single MIDI channel.
* Generally, each MidiChannel method processes a like-named MIDI
* "channel voice" or "channel mode" message as defined by the MIDI specification. However,
* MidiChannel adds some "get" methods that retrieve the value
* most recently set by one of the standard MIDI channel messages. Similarly,
* methods for per-channel solo and mute have been added.
*
* A {@link Synthesizer} object has a collection
* of MidiChannels, usually one for each of the 16 channels
* prescribed by the MIDI 1.0 specification. The Synthesizer
* generates sound when its MidiChannels receive
* noteOn messages.
*
* See the MIDI 1.0 Specification for more information about the prescribed
* behavior of the MIDI channel messages, which are not exhaustively
* documented here. The specification is titled MIDI Reference:
* The Complete MIDI 1.0 Detailed Specification, and is published by
* the MIDI Manufacturer's Association (
* http://www.midi.org).
*
* MIDI was originally a protocol for reporting the gestures of a keyboard
* musician. This genesis is visible in the MidiChannel API, which
* preserves such MIDI concepts as key number, key velocity, and key pressure.
* It should be understood that the MIDI data does not necessarily originate
* with a keyboard player (the source could be a different kind of musician, or
* software). Some devices might generate constant values for velocity
* and pressure, regardless of how the note was performed.
* Also, the MIDI specification often leaves it up to the
* synthesizer to use the data in the way the implementor sees fit. For
* example, velocity data need not always be mapped to volume and/or brightness.
*
* @see Synthesizer#getChannels
*
* @author David Rivas
* @author Kara Kytle
*/
public interface MidiChannel {
/**
* Starts the specified note sounding. The key-down velocity
* usually controls the note's volume and/or brightness.
* If velocity is zero, this method instead acts like
* {@link #noteOff(int)}, terminating the note.
*
* @param noteNumber the MIDI note number, from 0 to 127 (60 = Middle C)
* @param velocity the speed with which the key was depressed
*
* @see #noteOff(int, int)
*/
public void noteOn(int noteNumber, int velocity);
/**
* Turns the specified note off. The key-up velocity, if not ignored, can
* be used to affect how quickly the note decays.
* In any case, the note might not die away instantaneously; its decay
* rate is determined by the internals of the Instrument.
* If the Hold Pedal (a controller; see
* {@link #controlChange(int, int) controlChange})
* is down, the effect of this method is deferred until the pedal is
* released.
*
*
* @param noteNumber the MIDI note number, from 0 to 127 (60 = Middle C)
* @param velocity the speed with which the key was released
*
* @see #noteOff(int)
* @see #noteOn
* @see #allNotesOff
* @see #allSoundOff
*/
public void noteOff(int noteNumber, int velocity);
/**
* Turns the specified note off.
*
* @param noteNumber the MIDI note number, from 0 to 127 (60 = Middle C)
*
* @see #noteOff(int, int)
*/
public void noteOff(int noteNumber);
/**
* Reacts to a change in the specified note's key pressure.
* Polyphonic key pressure
* allows a keyboard player to press multiple keys simultaneously, each
* with a different amount of pressure. The pressure, if not ignored,
* is typically used to vary such features as the volume, brightness,
* or vibrato of the note.
*
* It is possible that the underlying synthesizer
* does not support this MIDI message. In order
* to verify that setPolyPressure
* was successful, use getPolyPressure.
*
* @param noteNumber the MIDI note number, from 0 to 127 (60 = Middle C)
* @param pressure value for the specified key, from 0 to 127 (127 =
* maximum pressure)
*
* @see #getPolyPressure(int)
*/
public void setPolyPressure(int noteNumber, int pressure);
/**
* Obtains the pressure with which the specified key is being depressed.
*
* @param noteNumber the MIDI note number, from 0 to 127 (60 = Middle C)
*
* If the device does not support setting poly pressure,
* this method always returns 0. Calling
* setPolyPressure will have no effect then.
*
* @return the amount of pressure for that note, from 0 to 127
* (127 = maximum pressure)
*
* @see #setPolyPressure(int, int)
*/
public int getPolyPressure(int noteNumber);
/**
* Reacts to a change in the keyboard pressure. Channel
* pressure indicates how hard the keyboard player is depressing
* the entire keyboard. This can be the maximum or
* average of the per-key pressure-sensor values, as set by
* setPolyPressure. More commonly, it is a measurement of
* a single sensor on a device that doesn't implement polyphonic key
* pressure. Pressure can be used to control various aspects of the sound,
* as described under {@link #setPolyPressure(int, int) setPolyPressure}.
*
* It is possible that the underlying synthesizer
* does not support this MIDI message. In order
* to verify that setChannelPressure
* was successful, use getChannelPressure.
*
* @param pressure the pressure with which the keyboard is being depressed,
* from 0 to 127 (127 = maximum pressure)
* @see #setPolyPressure(int, int)
* @see #getChannelPressure
*/
public void setChannelPressure(int pressure);
/**
* Obtains the channel's keyboard pressure.
* If the device does not support setting channel pressure,
* this method always returns 0. Calling
* setChannelPressure will have no effect then.
*
* @return the amount of pressure for that note,
* from 0 to 127 (127 = maximum pressure)
*
* @see #setChannelPressure(int)
*/
public int getChannelPressure();
/**
* Reacts to a change in the specified controller's value. A controller
* is some control other than a keyboard key, such as a
* switch, slider, pedal, wheel, or breath-pressure sensor.
* The MIDI 1.0 Specification provides standard numbers for typical
* controllers on MIDI devices, and describes the intended effect
* for some of the controllers.
* The way in which an
* Instrument reacts to a controller change may be
* specific to the Instrument.
*
* The MIDI 1.0 Specification defines both 7-bit controllers * and 14-bit controllers. Continuous controllers, such * as wheels and sliders, typically have 14 bits (two MIDI bytes), * while discrete controllers, such as switches, typically have 7 bits * (one MIDI byte). Refer to the specification to see the * expected resolution for each type of control. *
* Controllers 64 through 95 (0x40 - 0x5F) allow 7-bit precision.
* The value of a 7-bit controller is set completely by the
* value argument. An additional set of controllers
* provide 14-bit precision by using two controller numbers, one
* for the most significant 7 bits and another for the least significant
* 7 bits. Controller numbers 0 through 31 (0x00 - 0x1F) control the
* most significant 7 bits of 14-bit controllers; controller numbers
* 32 through 63 (0x20 - 0x3F) control the least significant 7 bits of
* these controllers. For example, controller number 7 (0x07) controls
* the upper 7 bits of the channel volume controller, and controller
* number 39 (0x27) controls the lower 7 bits.
* The value of a 14-bit controller is determined
* by the interaction of the two halves. When the most significant 7 bits
* of a controller are set (using controller numbers 0 through 31), the
* lower 7 bits are automatically set to 0. The corresponding controller
* number for the lower 7 bits may then be used to further modulate the
* controller value.
*
* It is possible that the underlying synthesizer
* does not support a specific controller message. In order
* to verify that a call to controlChange
* was successful, use getController.
*
* @param controller the controller number (0 to 127; see the MIDI
* 1.0 Specification for the interpretation)
* @param value the value to which the specified controller is changed (0 to 127)
*
* @see #getController(int)
*/
public void controlChange(int controller, int value);
/**
* Obtains the current value of the specified controller. The return
* value is represented with 7 bits. For 14-bit controllers, the MSB and
* LSB controller value needs to be obtained separately. For example,
* the 14-bit value of the volume controller can be calculated by
* multiplying the value of controller 7 (0x07, channel volume MSB)
* with 128 and adding the
* value of controller 39 (0x27, channel volume LSB).
*
* If the device does not support setting a specific controller,
* this method returns 0 for that controller.
* Calling controlChange will have no effect then.
*
* @param controller the number of the controller whose value is desired.
* The allowed range is 0-127; see the MIDI
* 1.0 Specification for the interpretation.
*
* @return the current value of the specified controller (0 to 127)
*
* @see #controlChange(int, int)
*/
public int getController(int controller);
/**
* Changes a program (patch). This selects a specific
* instrument from the currently selected bank of instruments.
*
* The MIDI specification does not * dictate whether notes that are already sounding should switch * to the new instrument (timbre) or continue with their original timbre * until terminated by a note-off. *
* The program number is zero-based (expressed from 0 to 127).
* Note that MIDI hardware displays and literature about MIDI
* typically use the range 1 to 128 instead.
*
* It is possible that the underlying synthesizer
* does not support a specific program. In order
* to verify that a call to programChange
* was successful, use getProgram.
*
* @param program the program number to switch to (0 to 127)
*
* @see #programChange(int, int)
* @see #getProgram()
*/
public void programChange(int program);
/**
* Changes the program using bank and program (patch) numbers.
*
* It is possible that the underlying synthesizer
* does not support a specific bank, or program. In order
* to verify that a call to programChange
* was successful, use getProgram and
* getController.
* Since banks are changed by way of control changes,
* you can verify the current bank with the following
* statement:
*
* int bank = (getController(0) * 128)
* + getController(32);
*
*
* @param bank the bank number to switch to (0 to 16383)
* @param program the program (patch) to use in the specified bank (0 to 127)
* @see #programChange(int)
* @see #getProgram()
*/
public void programChange(int bank, int program);
/**
* Obtains the current program number for this channel.
* @return the program number of the currently selected patch
* @see Patch#getProgram
* @see Synthesizer#loadInstrument
* @see #programChange(int)
*/
public int getProgram();
/**
* Changes the pitch offset for all notes on this channel.
* This affects all currently sounding notes as well as subsequent ones.
* (For pitch bend to cease, the value needs to be reset to the
* center position.)
* The MIDI specification
* stipulates that pitch bend be a 14-bit value, where zero
* is maximum downward bend, 16383 is maximum upward bend, and
* 8192 is the center (no pitch bend). The actual
* amount of pitch change is not specified; it can be changed by
* a pitch-bend sensitivity setting. However, the General MIDI
* specification says that the default range should be two semitones
* up and down from center.
*
* It is possible that the underlying synthesizer
* does not support this MIDI message. In order
* to verify that setPitchBend
* was successful, use getPitchBend.
*
* @param bend the amount of pitch change, as a nonnegative 14-bit value
* (8192 = no bend)
*
* @see #getPitchBend
*/
public void setPitchBend(int bend);
/**
* Obtains the upward or downward pitch offset for this channel.
* If the device does not support setting pitch bend,
* this method always returns 8192. Calling
* setPitchBend will have no effect then.
*
* @return bend amount, as a nonnegative 14-bit value (8192 = no bend)
*
* @see #setPitchBend(int)
*/
public int getPitchBend();
/**
* Resets all the implemented controllers to their default values.
*
* @see #controlChange(int, int)
*/
public void resetAllControllers();
/**
* Turns off all notes that are currently sounding on this channel.
* The notes might not die away instantaneously; their decay
* rate is determined by the internals of the Instrument.
* If the Hold Pedal controller (see
* {@link #controlChange(int, int) controlChange})
* is down, the effect of this method is deferred until the pedal is
* released.
*
* @see #allSoundOff
* @see #noteOff(int)
*/
public void allNotesOff();
/**
* Immediately turns off all sounding notes on this channel, ignoring the
* state of the Hold Pedal and the internal decay rate of the current
* Instrument.
*
* @see #allNotesOff
*/
public void allSoundOff();
/**
* Turns local control on or off. The default is for local control
* to be on. The "on" setting means that if a device is capable
* of both synthesizing sound and transmitting MIDI messages,
* it will synthesize sound in response to the note-on and
* note-off messages that it itself transmits. It will also respond
* to messages received from other transmitting devices.
* The "off" setting means that the synthesizer will ignore its
* own transmitted MIDI messages, but not those received from other devices.
*
* It is possible that the underlying synthesizer
* does not support local control. In order
* to verify that a call to localControl
* was successful, check the return value.
*
* @param on true to turn local control on, false
* to turn local control off
* @return the new local-control value, or false
* if local control is not supported
*
*/
public boolean localControl(boolean on);
/**
* Turns mono mode on or off. In mono mode, the channel synthesizes
* only one note at a time. In poly mode (identical to mono mode off),
* the channel can synthesize multiple notes simultaneously.
* The default is mono off (poly mode on).
*
* "Mono" is short for the word "monophonic," which in this context
* is opposed to the word "polyphonic" and refers to a single synthesizer
* voice per MIDI channel. It
* has nothing to do with how many audio channels there might be
* (as in "monophonic" versus "stereophonic" recordings).
*
* It is possible that the underlying synthesizer
* does not support mono mode. In order
* to verify that a call to setMono
* was successful, use getMono.
*
* @param on true to turn mono mode on, false to
* turn it off (which means turning poly mode on).
*
* @see #getMono
* @see VoiceStatus
*/
public void setMono(boolean on);
/**
* Obtains the current mono/poly mode.
* Synthesizers that do not allow changing mono/poly mode
* will always return the same value, regardless
* of calls to setMono.
* @return true if mono mode is on, otherwise
* false (meaning poly mode is on).
*
* @see #setMono(boolean)
*/
public boolean getMono();
/**
* Turns omni mode on or off. In omni mode, the channel responds
* to messages sent on all channels. When omni is off, the channel
* responds only to messages sent on its channel number.
* The default is omni off.
*
* It is possible that the underlying synthesizer
* does not support omni mode. In order
* to verify that setOmni
* was successful, use getOmni.
*
* @param on true to turn omni mode on, false to
* turn it off.
*
* @see #getOmni
* @see VoiceStatus
*/
public void setOmni(boolean on);
/**
* Obtains the current omni mode.
* Synthesizers that do not allow changing the omni mode
* will always return the same value, regardless
* of calls to setOmni.
* @return true if omni mode is on, otherwise
* false (meaning omni mode is off).
*
* @see #setOmni(boolean)
*/
public boolean getOmni();
/**
* Sets the mute state for this channel. A value of
* true means the channel is to be muted, false
* means the channel can sound (if other channels are not soloed).
*
* Unlike {@link #allSoundOff()}, this method
* applies to only a specific channel, not to all channels. Further, it
* silences not only currently sounding notes, but also subsequently
* received notes.
*
* It is possible that the underlying synthesizer
* does not support muting channels. In order
* to verify that a call to setMute
* was successful, use getMute.
*
* @param mute the new mute state
*
* @see #getMute
* @see #setSolo(boolean)
*/
public void setMute(boolean mute);
/**
* Obtains the current mute state for this channel.
* If the underlying synthesizer does not support
* muting this channel, this method always returns
* false.
*
* @return true the channel is muted,
* or false if not
*
* @see #setMute(boolean)
*/
public boolean getMute();
/**
* Sets the solo state for this channel.
* If solo is true only this channel
* and other soloed channels will sound. If solo
* is false then only other soloed channels will
* sound, unless no channels are soloed, in which case all
* unmuted channels will sound.
*
* It is possible that the underlying synthesizer
* does not support solo channels. In order
* to verify that a call to setSolo
* was successful, use getSolo.
*
* @param soloState new solo state for the channel
* @see #getSolo()
*/
public void setSolo(boolean soloState);
/**
* Obtains the current solo state for this channel.
* If the underlying synthesizer does not support
* solo on this channel, this method always returns
* false.
*
* @return true the channel is solo,
* or false if not
*
* @see #setSolo(boolean)
*/
public boolean getSolo();
}