718 lines
24 KiB
Python
718 lines
24 KiB
Python
"""pygame.midi
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pygame module for interacting with midi input and output.
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The midi module can send output to midi devices, and get input
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from midi devices. It can also list midi devices on the system.
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Including real midi devices, and virtual ones.
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It uses the portmidi library. Is portable to which ever platforms
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portmidi supports (currently windows, OSX, and linux).
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This uses pyportmidi for now, but may use its own bindings at some
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point in the future. The pyportmidi bindings are included with pygame.
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New in pygame 1.9.0.
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"""
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# TODO: finish writing tests.
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# - likely as interactive tests... so you'd need to plug in
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# a midi device.
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# TODO: create a background thread version for input threads.
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# - that can automatically inject input into the event queue
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# once the input object is running. Like joysticks.
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import math
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import atexit
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import pygame
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import pygame.locals
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import pygame.pypm as _pypm
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# For backward compatibility.
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MIDIIN = pygame.locals.MIDIIN
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MIDIOUT = pygame.locals.MIDIOUT
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__all__ = [
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"Input",
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"MIDIIN",
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"MIDIOUT",
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"MidiException",
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"Output",
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"get_count",
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"get_default_input_id",
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"get_default_output_id",
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"get_device_info",
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"init",
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"midis2events",
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"quit",
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"get_init",
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"time",
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"frequency_to_midi",
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"midi_to_frequency",
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"midi_to_ansi_note",
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]
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__theclasses__ = ["Input", "Output"]
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def _module_init(state=None):
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# this is a sneaky dodge to store module level state in a non-public
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# function. Helps us dodge using globals.
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if state is not None:
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_module_init.value = state
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return state
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try:
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_module_init.value
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except AttributeError:
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return False
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return _module_init.value
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def init():
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"""initialize the midi module
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pygame.midi.init(): return None
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Call the initialisation function before using the midi module.
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It is safe to call this more than once.
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"""
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if not _module_init():
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_pypm.Initialize()
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_module_init(True)
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atexit.register(quit)
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def quit(): # pylint: disable=redefined-builtin
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"""uninitialize the midi module
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pygame.midi.quit(): return None
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Called automatically atexit if you don't call it.
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It is safe to call this function more than once.
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"""
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if _module_init():
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# TODO: find all Input and Output classes and close them first?
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_pypm.Terminate()
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_module_init(False)
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def get_init():
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"""returns True if the midi module is currently initialized
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pygame.midi.get_init(): return bool
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Returns True if the pygame.midi module is currently initialized.
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New in pygame 1.9.5.
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"""
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return _module_init()
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def _check_init():
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if not _module_init():
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raise RuntimeError("pygame.midi not initialised.")
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def get_count():
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"""gets the number of devices.
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pygame.midi.get_count(): return num_devices
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Device ids range from 0 to get_count() -1
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"""
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_check_init()
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return _pypm.CountDevices()
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def get_default_input_id():
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"""gets default input device number
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pygame.midi.get_default_input_id(): return default_id
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Return the default device ID or -1 if there are no devices.
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The result can be passed to the Input()/Output() class.
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On the PC, the user can specify a default device by
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setting an environment variable. For example, to use device #1.
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set PM_RECOMMENDED_INPUT_DEVICE=1
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The user should first determine the available device ID by using
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the supplied application "testin" or "testout".
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In general, the registry is a better place for this kind of info,
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and with USB devices that can come and go, using integers is not
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very reliable for device identification. Under Windows, if
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PM_RECOMMENDED_OUTPUT_DEVICE (or PM_RECOMMENDED_INPUT_DEVICE) is
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*NOT* found in the environment, then the default device is obtained
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by looking for a string in the registry under:
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HKEY_LOCAL_MACHINE/SOFTWARE/PortMidi/Recommended_Input_Device
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and HKEY_LOCAL_MACHINE/SOFTWARE/PortMidi/Recommended_Output_Device
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for a string. The number of the first device with a substring that
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matches the string exactly is returned. For example, if the string
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in the registry is "USB", and device 1 is named
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"In USB MidiSport 1x1", then that will be the default
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input because it contains the string "USB".
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In addition to the name, get_device_info() returns "interf", which
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is the interface name. (The "interface" is the underlying software
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system or API used by PortMidi to access devices. Examples are
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MMSystem, DirectX (not implemented), ALSA, OSS (not implemented), etc.)
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At present, the only Win32 interface is "MMSystem", the only Linux
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interface is "ALSA", and the only Max OS X interface is "CoreMIDI".
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To specify both the interface and the device name in the registry,
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separate the two with a comma and a space, e.g.:
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MMSystem, In USB MidiSport 1x1
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In this case, the string before the comma must be a substring of
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the "interf" string, and the string after the space must be a
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substring of the "name" name string in order to match the device.
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Note: in the current release, the default is simply the first device
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(the input or output device with the lowest PmDeviceID).
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"""
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_check_init()
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return _pypm.GetDefaultInputDeviceID()
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def get_default_output_id():
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"""gets default output device number
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pygame.midi.get_default_output_id(): return default_id
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Return the default device ID or -1 if there are no devices.
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The result can be passed to the Input()/Output() class.
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On the PC, the user can specify a default device by
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setting an environment variable. For example, to use device #1.
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set PM_RECOMMENDED_OUTPUT_DEVICE=1
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The user should first determine the available device ID by using
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the supplied application "testin" or "testout".
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In general, the registry is a better place for this kind of info,
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and with USB devices that can come and go, using integers is not
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very reliable for device identification. Under Windows, if
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PM_RECOMMENDED_OUTPUT_DEVICE (or PM_RECOMMENDED_INPUT_DEVICE) is
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*NOT* found in the environment, then the default device is obtained
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by looking for a string in the registry under:
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HKEY_LOCAL_MACHINE/SOFTWARE/PortMidi/Recommended_Input_Device
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and HKEY_LOCAL_MACHINE/SOFTWARE/PortMidi/Recommended_Output_Device
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for a string. The number of the first device with a substring that
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matches the string exactly is returned. For example, if the string
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in the registry is "USB", and device 1 is named
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"In USB MidiSport 1x1", then that will be the default
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input because it contains the string "USB".
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In addition to the name, get_device_info() returns "interf", which
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is the interface name. (The "interface" is the underlying software
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system or API used by PortMidi to access devices. Examples are
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MMSystem, DirectX (not implemented), ALSA, OSS (not implemented), etc.)
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At present, the only Win32 interface is "MMSystem", the only Linux
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interface is "ALSA", and the only Max OS X interface is "CoreMIDI".
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To specify both the interface and the device name in the registry,
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separate the two with a comma and a space, e.g.:
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MMSystem, In USB MidiSport 1x1
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In this case, the string before the comma must be a substring of
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the "interf" string, and the string after the space must be a
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substring of the "name" name string in order to match the device.
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Note: in the current release, the default is simply the first device
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(the input or output device with the lowest PmDeviceID).
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"""
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_check_init()
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return _pypm.GetDefaultOutputDeviceID()
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def get_device_info(an_id):
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"""returns information about a midi device
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pygame.midi.get_device_info(an_id): return (interf, name,
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input, output,
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opened)
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interf - a byte string describing the device interface, eg b'ALSA'.
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name - a byte string for the name of the device, eg b'Midi Through Port-0'
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input - 0, or 1 if the device is an input device.
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output - 0, or 1 if the device is an output device.
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opened - 0, or 1 if the device is opened.
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If the id is out of range, the function returns None.
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"""
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_check_init()
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return _pypm.GetDeviceInfo(an_id)
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class Input:
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"""Input is used to get midi input from midi devices.
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Input(device_id)
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Input(device_id, buffer_size)
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buffer_size - the number of input events to be buffered waiting to
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be read using Input.read()
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"""
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def __init__(self, device_id, buffer_size=4096):
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"""
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The buffer_size specifies the number of input events to be buffered
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waiting to be read using Input.read().
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"""
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_check_init()
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if device_id == -1:
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raise MidiException(
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"Device id is -1, not a valid output id. "
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"-1 usually means there were no default "
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"Output devices."
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)
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try:
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result = get_device_info(device_id)
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except TypeError:
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raise TypeError("an integer is required")
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except OverflowError:
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raise OverflowError("long int too large to convert to int")
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# and now some nasty looking error checking, to provide nice error
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# messages to the kind, lovely, midi using people of wherever.
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if result:
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_, _, is_input, is_output, _ = result
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if is_input:
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try:
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self._input = _pypm.Input(device_id, buffer_size)
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except TypeError:
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raise TypeError("an integer is required")
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self.device_id = device_id
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elif is_output:
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raise MidiException(
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"Device id given is not a valid input id, it is an output id."
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)
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else:
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raise MidiException("Device id given is not a valid input id.")
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else:
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raise MidiException("Device id invalid, out of range.")
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def _check_open(self):
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if self._input is None:
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raise MidiException("midi not open.")
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def close(self):
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"""closes a midi stream, flushing any pending buffers.
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Input.close(): return None
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PortMidi attempts to close open streams when the application
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exits -- this is particularly difficult under Windows.
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"""
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_check_init()
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if self._input is not None:
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self._input.Close()
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self._input = None
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def read(self, num_events):
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"""reads num_events midi events from the buffer.
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Input.read(num_events): return midi_event_list
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Reads from the Input buffer and gives back midi events.
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[[[status,data1,data2,data3],timestamp],
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[[status,data1,data2,data3],timestamp],...]
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"""
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_check_init()
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self._check_open()
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return self._input.Read(num_events)
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def poll(self):
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"""returns true if there's data, or false if not.
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Input.poll(): return Bool
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raises a MidiException on error.
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"""
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_check_init()
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self._check_open()
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result = self._input.Poll()
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if result == _pypm.TRUE:
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return True
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if result == _pypm.FALSE:
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return False
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err_text = _pypm.GetErrorText(result)
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raise MidiException((result, err_text))
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class Output:
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"""Output is used to send midi to an output device
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Output(device_id)
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Output(device_id, latency = 0)
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Output(device_id, buffer_size = 4096)
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Output(device_id, latency, buffer_size)
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The buffer_size specifies the number of output events to be
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buffered waiting for output. (In some cases -- see below --
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PortMidi does not buffer output at all and merely passes data
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to a lower-level API, in which case buffersize is ignored.)
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latency is the delay in milliseconds applied to timestamps to determine
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when the output should actually occur. (If latency is < 0, 0 is
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assumed.)
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If latency is zero, timestamps are ignored and all output is delivered
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immediately. If latency is greater than zero, output is delayed until
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the message timestamp plus the latency. (NOTE: time is measured
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relative to the time source indicated by time_proc. Timestamps are
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absolute, not relative delays or offsets.) In some cases, PortMidi
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can obtain better timing than your application by passing timestamps
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along to the device driver or hardware. Latency may also help you
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to synchronize midi data to audio data by matching midi latency to
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the audio buffer latency.
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"""
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def __init__(self, device_id, latency=0, buffer_size=256):
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"""Output(device_id)
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Output(device_id, latency = 0)
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Output(device_id, buffer_size = 4096)
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Output(device_id, latency, buffer_size)
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The buffer_size specifies the number of output events to be
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buffered waiting for output. (In some cases -- see below --
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PortMidi does not buffer output at all and merely passes data
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to a lower-level API, in which case buffersize is ignored.)
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latency is the delay in milliseconds applied to timestamps to determine
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when the output should actually occur. (If latency is < 0, 0 is
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assumed.)
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If latency is zero, timestamps are ignored and all output is delivered
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immediately. If latency is greater than zero, output is delayed until
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the message timestamp plus the latency. (NOTE: time is measured
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relative to the time source indicated by time_proc. Timestamps are
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absolute, not relative delays or offsets.) In some cases, PortMidi
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can obtain better timing than your application by passing timestamps
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along to the device driver or hardware. Latency may also help you
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to synchronize midi data to audio data by matching midi latency to
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the audio buffer latency.
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"""
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_check_init()
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self._aborted = 0
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if device_id == -1:
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raise MidiException(
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"Device id is -1, not a valid output id."
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" -1 usually means there were no default "
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"Output devices."
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)
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try:
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result = get_device_info(device_id)
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except TypeError:
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raise TypeError("an integer is required")
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except OverflowError:
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raise OverflowError("long int too large to convert to int")
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# and now some nasty looking error checking, to provide nice error
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# messages to the kind, lovely, midi using people of wherever.
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if result:
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_, _, is_input, is_output, _ = result
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if is_output:
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try:
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self._output = _pypm.Output(device_id, latency, buffer_size)
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except TypeError:
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raise TypeError("an integer is required")
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self.device_id = device_id
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elif is_input:
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raise MidiException(
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"Device id given is not a valid output id, it is an input id."
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)
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else:
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raise MidiException("Device id given is not a valid output id.")
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else:
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raise MidiException("Device id invalid, out of range.")
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def _check_open(self):
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if self._output is None:
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raise MidiException("midi not open.")
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if self._aborted:
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raise MidiException("midi aborted.")
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def close(self):
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"""closes a midi stream, flushing any pending buffers.
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Output.close(): return None
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PortMidi attempts to close open streams when the application
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exits -- this is particularly difficult under Windows.
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"""
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_check_init()
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if self._output is not None:
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self._output.Close()
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self._output = None
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def abort(self):
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"""terminates outgoing messages immediately
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Output.abort(): return None
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The caller should immediately close the output port;
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this call may result in transmission of a partial midi message.
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There is no abort for Midi input because the user can simply
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ignore messages in the buffer and close an input device at
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any time.
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"""
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_check_init()
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if self._output:
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self._output.Abort()
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self._aborted = 1
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def write(self, data):
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"""writes a list of midi data to the Output
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Output.write(data)
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writes series of MIDI information in the form of a list:
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write([[[status <,data1><,data2><,data3>],timestamp],
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[[status <,data1><,data2><,data3>],timestamp],...])
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<data> fields are optional
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example: choose program change 1 at time 20000 and
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send note 65 with velocity 100 500 ms later.
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write([[[0xc0,0,0],20000],[[0x90,60,100],20500]])
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notes:
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1. timestamps will be ignored if latency = 0.
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2. To get a note to play immediately, send MIDI info with
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timestamp read from function Time.
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3. understanding optional data fields:
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write([[[0xc0,0,0],20000]]) is equivalent to
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write([[[0xc0],20000]])
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Can send up to 1024 elements in your data list, otherwise an
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IndexError exception is raised.
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"""
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_check_init()
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self._check_open()
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self._output.Write(data)
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def write_short(self, status, data1=0, data2=0):
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"""write_short(status <, data1><, data2>)
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Output.write_short(status)
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Output.write_short(status, data1 = 0, data2 = 0)
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output MIDI information of 3 bytes or less.
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data fields are optional
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status byte could be:
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0xc0 = program change
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0x90 = note on
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etc.
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data bytes are optional and assumed 0 if omitted
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example: note 65 on with velocity 100
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write_short(0x90,65,100)
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"""
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_check_init()
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self._check_open()
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self._output.WriteShort(status, data1, data2)
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def write_sys_ex(self, when, msg):
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"""writes a timestamped system-exclusive midi message.
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Output.write_sys_ex(when, msg)
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msg - can be a *list* or a *string*
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when - a timestamp in milliseconds
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example:
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(assuming o is an onput MIDI stream)
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o.write_sys_ex(0,'\\xF0\\x7D\\x10\\x11\\x12\\x13\\xF7')
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is equivalent to
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o.write_sys_ex(pygame.midi.time(),
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[0xF0,0x7D,0x10,0x11,0x12,0x13,0xF7])
|
|
"""
|
|
_check_init()
|
|
self._check_open()
|
|
self._output.WriteSysEx(when, msg)
|
|
|
|
def note_on(self, note, velocity, channel=0):
|
|
"""turns a midi note on. Note must be off.
|
|
Output.note_on(note, velocity, channel=0)
|
|
|
|
note is an integer from 0 to 127
|
|
velocity is an integer from 0 to 127
|
|
channel is an integer from 0 to 15
|
|
|
|
Turn a note on in the output stream. The note must already
|
|
be off for this to work correctly.
|
|
"""
|
|
if not 0 <= channel <= 15:
|
|
raise ValueError("Channel not between 0 and 15.")
|
|
|
|
self.write_short(0x90 + channel, note, velocity)
|
|
|
|
def note_off(self, note, velocity=0, channel=0):
|
|
"""turns a midi note off. Note must be on.
|
|
Output.note_off(note, velocity=0, channel=0)
|
|
|
|
note is an integer from 0 to 127
|
|
velocity is an integer from 0 to 127 (release velocity)
|
|
channel is an integer from 0 to 15
|
|
|
|
Turn a note off in the output stream. The note must already
|
|
be on for this to work correctly.
|
|
"""
|
|
if not 0 <= channel <= 15:
|
|
raise ValueError("Channel not between 0 and 15.")
|
|
|
|
self.write_short(0x80 + channel, note, velocity)
|
|
|
|
def set_instrument(self, instrument_id, channel=0):
|
|
"""select an instrument for a channel, with a value between 0 and 127
|
|
Output.set_instrument(instrument_id, channel=0)
|
|
|
|
Also called "patch change" or "program change".
|
|
"""
|
|
if not 0 <= instrument_id <= 127:
|
|
raise ValueError(f"Undefined instrument id: {instrument_id}")
|
|
|
|
if not 0 <= channel <= 15:
|
|
raise ValueError("Channel not between 0 and 15.")
|
|
|
|
self.write_short(0xC0 + channel, instrument_id)
|
|
|
|
def pitch_bend(self, value=0, channel=0):
|
|
"""modify the pitch of a channel.
|
|
Output.pitch_bend(value=0, channel=0)
|
|
|
|
Adjust the pitch of a channel. The value is a signed integer
|
|
from -8192 to +8191. For example, 0 means "no change", +4096 is
|
|
typically a semitone higher, and -8192 is 1 whole tone lower (though
|
|
the musical range corresponding to the pitch bend range can also be
|
|
changed in some synthesizers).
|
|
|
|
If no value is given, the pitch bend is returned to "no change".
|
|
"""
|
|
if not 0 <= channel <= 15:
|
|
raise ValueError("Channel not between 0 and 15.")
|
|
|
|
if not -8192 <= value <= 8191:
|
|
raise ValueError(
|
|
f"Pitch bend value must be between -8192 and +8191, not {value}."
|
|
)
|
|
|
|
# "The 14 bit value of the pitch bend is defined so that a value of
|
|
# 0x2000 is the center corresponding to the normal pitch of the note
|
|
# (no pitch change)." so value=0 should send 0x2000
|
|
value = value + 0x2000
|
|
lsb = value & 0x7F # keep least 7 bits
|
|
msb = value >> 7
|
|
self.write_short(0xE0 + channel, lsb, msb)
|
|
|
|
|
|
# MIDI commands
|
|
#
|
|
# 0x80 Note Off (note_off)
|
|
# 0x90 Note On (note_on)
|
|
# 0xA0 Aftertouch
|
|
# 0xB0 Continuous controller
|
|
# 0xC0 Patch change (set_instrument?)
|
|
# 0xD0 Channel Pressure
|
|
# 0xE0 Pitch bend
|
|
# 0xF0 (non-musical commands)
|
|
|
|
|
|
def time():
|
|
"""returns the current time in ms of the PortMidi timer
|
|
pygame.midi.time(): return time
|
|
|
|
The time is reset to 0, when the module is inited.
|
|
"""
|
|
_check_init()
|
|
return _pypm.Time()
|
|
|
|
|
|
def midis2events(midis, device_id):
|
|
"""converts midi events to pygame events
|
|
pygame.midi.midis2events(midis, device_id): return [Event, ...]
|
|
|
|
Takes a sequence of midi events and returns list of pygame events.
|
|
"""
|
|
evs = []
|
|
for midi in midis:
|
|
((status, data1, data2, data3), timestamp) = midi
|
|
|
|
event = pygame.event.Event(
|
|
MIDIIN,
|
|
status=status,
|
|
data1=data1,
|
|
data2=data2,
|
|
data3=data3,
|
|
timestamp=timestamp,
|
|
vice_id=device_id,
|
|
)
|
|
evs.append(event)
|
|
|
|
return evs
|
|
|
|
|
|
class MidiException(Exception):
|
|
"""exception that pygame.midi functions and classes can raise
|
|
MidiException(errno)
|
|
"""
|
|
|
|
def __init__(self, value):
|
|
super().__init__(value)
|
|
self.parameter = value
|
|
|
|
def __str__(self):
|
|
return repr(self.parameter)
|
|
|
|
|
|
def frequency_to_midi(frequency):
|
|
"""converts a frequency into a MIDI note.
|
|
|
|
Rounds to the closest midi note.
|
|
|
|
::Examples::
|
|
|
|
>>> frequency_to_midi(27.5)
|
|
21
|
|
>>> frequency_to_midi(36.7)
|
|
26
|
|
>>> frequency_to_midi(4186.0)
|
|
108
|
|
"""
|
|
return int(round(69 + (12 * math.log(frequency / 440.0)) / math.log(2)))
|
|
|
|
|
|
def midi_to_frequency(midi_note):
|
|
"""Converts a midi note to a frequency.
|
|
|
|
::Examples::
|
|
|
|
>>> midi_to_frequency(21)
|
|
27.5
|
|
>>> midi_to_frequency(26)
|
|
36.7
|
|
>>> midi_to_frequency(108)
|
|
4186.0
|
|
"""
|
|
return round(440.0 * 2 ** ((midi_note - 69) * (1.0 / 12.0)), 1)
|
|
|
|
|
|
def midi_to_ansi_note(midi_note):
|
|
"""returns the Ansi Note name for a midi number.
|
|
|
|
::Examples::
|
|
|
|
>>> midi_to_ansi_note(21)
|
|
'A0'
|
|
>>> midi_to_ansi_note(102)
|
|
'F#7'
|
|
>>> midi_to_ansi_note(108)
|
|
'C8'
|
|
"""
|
|
notes = ["A", "A#", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#"]
|
|
num_notes = 12
|
|
note_name = notes[int((midi_note - 21) % num_notes)]
|
|
note_number = (midi_note - 12) // num_notes
|
|
return f"{note_name}{note_number}"
|