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Version: Matrix OS 3.2

MidiPacket

Preview notice​

The MatrixOS Python API is in preview and is subject to change; it may contain errors.

Overview​

The MidiPacket class encapsulates a MIDI message, including its port, status, and data. It provides utility methods for creating, analyzing, and manipulating MIDI messages for both input and output operations.

The Python MidiPacket class is implemented in Applications/Python/PikaPython/MatrixOS_MidiPacket.py with type hints in Applications/Python/PikaPython/_MatrixOS_MidiPacket.pyi.

Constructor​

MidiPacket(*val)​

def __init__(self, *val) -> None

Creates a MIDI packet with variable arguments depending on the message type.

Parameters:

  • *val: Variable arguments for constructing different types of MIDI messages

Static Factory Methods​

Note Messages​

NoteOn​

def NoteOn(self, channel: int, note: int, velocity: int = 127) -> MidiPacket

Creates a MIDI Note On message.

Parameters:

  • channel (int): MIDI channel (0-15)
  • note (int): MIDI note number (0-127)
  • velocity (int, optional): Note velocity (0-127, defaults to 127)

Returns:

  • MidiPacket: Note On packet

NoteOff​

def NoteOff(self, channel: int, note: int, velocity: int = 0) -> MidiPacket

Creates a MIDI Note Off message.

Parameters:

  • channel (int): MIDI channel (0-15)
  • note (int): MIDI note number (0-127)
  • velocity (int, optional): Release velocity (0-127, defaults to 0)

Control Messages​

ControlChange​

def ControlChange(self, channel: int, controller: int, value: int) -> MidiPacket

Creates a MIDI Control Change message.

Parameters:

  • channel (int): MIDI channel (0-15)
  • controller (int): Controller number (0-127)
  • value (int): Controller value (0-127)

ProgramChange​

def ProgramChange(self, channel: int, program: int) -> MidiPacket

Creates a MIDI Program Change message.

Parameters:

  • channel (int): MIDI channel (0-15)
  • program (int): Program number (0-127)

PitchBend​

def PitchBend(self, channel: int, value: int) -> MidiPacket

Creates a MIDI Pitch Bend message.

Parameters:

  • channel (int): MIDI channel (0-15)
  • value (int): Pitch bend value (0-16383, 8192 = center)

Pressure Messages​

AfterTouch​

def AfterTouch(self, channel: int, note: int, pressure: int) -> MidiPacket

Creates a MIDI Polyphonic Key Pressure (Aftertouch) message.

Parameters:

  • channel (int): MIDI channel (0-15)
  • note (int): MIDI note number (0-127)
  • pressure (int): Pressure value (0-127)

ChannelPressure​

def ChannelPressure(self, channel: int, pressure: int) -> MidiPacket

Creates a MIDI Channel Pressure message.

Parameters:

  • channel (int): MIDI channel (0-15)
  • pressure (int): Pressure value (0-127)

System Real-Time Messages​

Clock​

def Clock(self) -> MidiPacket

Creates a MIDI Clock message for tempo synchronization.

Start​

def Start(self) -> MidiPacket

Creates a MIDI Start message to begin sequencer playback.

Continue​

def Continue(self) -> MidiPacket

Creates a MIDI Continue message to resume sequencer playback.

Stop​

def Stop(self) -> MidiPacket

Creates a MIDI Stop message to halt sequencer playback.

ActiveSense​

def ActiveSense(self) -> MidiPacket

Creates a MIDI Active Sensing message.

Reset​

def Reset(self) -> MidiPacket

Creates a MIDI System Reset message.

System Common Messages​

SongPosition​

def SongPosition(self, position: int) -> MidiPacket

Creates a MIDI Song Position Pointer message.

Parameters:

  • position (int): Song position in MIDI beats

SongSelect​

def SongSelect(self, song: int) -> MidiPacket

Creates a MIDI Song Select message.

Parameters:

  • song (int): Song number (0-127)

TuneRequest​

def TuneRequest(self) -> MidiPacket

Creates a MIDI Tune Request message.

Getter Methods​

Port​

def Port(self) -> MidiPortID

Gets the MIDI port identifier for this packet.

Returns:

  • MidiPortID: The port identifier

Status​

def Status(self) -> MidiStatus

Gets the MIDI status/message type.

Returns:

  • MidiStatus: The message status type

Channel​

def Channel(self) -> int

Gets the MIDI channel number.

Returns:

  • int: Channel number (0-15)

Note​

def Note(self) -> int

Gets the MIDI note number or controller number.

Returns:

  • int: Note/controller value (0-127)

Controller​

def Controller(self) -> int

Gets the MIDI controller number (alias for Note()).

Returns:

  • int: Controller number (0-127)

Velocity​

def Velocity(self) -> int

Gets the velocity or pressure value.

Returns:

  • int: Velocity/pressure value (0-127)

Value​

def Value(self) -> int

Gets the value associated with the MIDI message (e.g., pitch bend, control change value).

Returns:

  • int: The message value

Setter Methods​

SetStatus​

def SetStatus(self, status: MidiStatus) -> None

Sets the MIDI status/message type.

SetChannel​

def SetChannel(self, channel: int) -> None

Sets the MIDI channel number.

SetNote​

def SetNote(self, note: int) -> None

Sets the MIDI note or controller number.

SetController​

def SetController(self, controller: int) -> None

Sets the MIDI controller number.

SetVelocity​

def SetVelocity(self, velocity: int) -> None

Sets the velocity or pressure value.

SetValue​

def SetValue(self, value: int) -> None

Sets the message value.

Helper Methods​

Length​

def Length(self) -> int

Gets the length of the MIDI message based on its status.

Returns:

  • int: Message length in bytes

SysEx​

def SysEx(self) -> bool

Checks if the message is a System Exclusive (SysEx) message.

Returns:

  • bool: True if SysEx message

SysExStart​

def SysExStart(self) -> bool

Checks if the message is the start of a SysEx message.

Returns:

  • bool: True if SysEx start message

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