Midistream¶

Package to synthesize and playback MIDI commands from Python for Android.

Midistream is a wrapper for the Bill Farmer Midi Driver, and includes libmidi.so libraries from the MidiDriver build.

Previous version was using system version of Sonivox EAS library and Audiostream for playback.

Generated documentation: https://midistream.readthedocs.org

Quick start development environment¶

midistream is included in PythonHere app, together with the Jupyter Notebook it could be used as a development environment.

Usage examples: https://herethere.me/examples/midi.html

Build¶

The following instructions are for building app with buildozer tool.

buildozer.spec requirements should include midistream and mididriver, path to midistream recipes directory should be set:

 requirements =
             mididriver,
             https://github.com/b3b/midistream/archive/master.zip,

p4a.local_recipes = /path/to/cloned/repo/recipes

App configuration example: buildozer.spec

Examples¶

See examples/ directory.

examples/instrument could be build with buildozer:

cd examples/instrument
buildozer android debug deploy run logcat

API¶

Midi¶

exception midistream.MIDIException[source]¶: MIDI error.

class midistream.ReverbPreset[source]¶

Parameter settings for reverb effect.

OFF = -1¶: Reverb effect off

LARGE_HALL = 0¶: Large hall preset

HALL = 1¶: Hall preset

CHAMBER = 2¶: Chamber preset

ROOM = 3¶: Room preset

class midistream.Synthesizer[source]¶

MIDI Synthesizer.

config¶: Synthesizer configuration dictionary.

volume¶

Master volume in dB, 100 is max.

Getter:	Returns the volume for the mix engine.
Setter:	Set the master volume for the mix engine.

reverb¶

Reverb effect preset.

Getter:	Returns curently used `ReverbPreset`.
Setter:	Set `ReverbPreset` to use.

close()[source]¶: Stop MIDI rendering and playback.

write(data: AnyStr)[source]¶: Write MIDI commands to synhtesizer stream.

Helpers¶

Helpers to work with MIDI messages.

midistream.helpers.midi_note_on(note: int, channel: int = 0, velocity: int = 64) → List[int][source]¶

MIDI 9nH message - note on.

>>> midi_note_on(70)
[144, 70, 64]
>>> midi_note_on(70, velocity=127, channel=15)
[159, 70, 127]

midistream.helpers.midi_note_off(note: int, channel: int = 0, velocity: int = 0) → List[int][source]¶

MIDI 8nH message - note off.

>>> midi_note_off(70)
[128, 70, 0]
>>> midi_note_off(70, channel=15)
[143, 70, 0]

midistream.helpers.midi_program_change(program: int, channel: int = 0) → List[int][source]¶

MIDI CnH message - program change.

>>> midi_program_change(80, 1)
[193, 80]

midistream.helpers.midi_control_change(controller: int, value: int = 0, channel: int = 0) → List[int][source]¶

MIDI BnH message - control change.

>>> midi_control_change(7, value=127, channel=1)
[177, 7, 127]

midistream.helpers.midi_command_increase_channel(command: List[int], inc: int) → List[int][source]¶

Increase channel number of a given command.

>>> command = [177, 7, 127]
>>> midi_command_increase_channel(command, -7)
[170, 7, 127]
>>> command
[177, 7, 127]

class midistream.helpers.Control[source]¶

Control function number for Control Change messages.

See: https://www.midi.org/specifications-old/item/table-3-control-change-messages-data-bytes-2

modulation = 1¶: Modulation Wheel

volume = 7¶: Channel Volume

pan = 10¶: Pan

all_sound_off = 120¶: All Sound Off

midistream.helpers.midi_channels() → Generator[int, None, None][source]¶

Generator of MIDI channels numbers, with percussion (9) channel omited.

>>> list(midi_channels())
[0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15]

midistream.helpers.midi_notes = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,...¶: All MIDI notes list (from 0 to 127)

midistream.helpers.note_name(note: int) → str[source]¶

Returns name with accidental and octave number for a given note number.

>>> note_name(60)
'C4'
>>> note_name(90)
'Fs6'

midistream.helpers.parse_note(text: str) → int[source]¶

Parse note number from text.

Parameters:	text – [Note name](optional: “s” - sharp, “b” - flat)[octave number]
Raises:	ValueError

>>> parse_note("C4")
60
>>> parse_note("Cs4")
61
>>> parse_note("Cb4")
59

class midistream.helpers.Note[source]¶

Note number.

>>> Note.A0
21
>>> Note.As0
22
>>> Note.Ab0
20
>>> Note.G9
127

midistream.helpers.midi_instruments = {0: 'Acoustic Grand Piano', 1: 'Bright Acoustic Pi...¶: MIDI instruments number => name dictionary

Usage Example¶

>>> from midistream import ReverbPreset, Synthesizer
>>> midi = Synthesizer()
>>> midi.config
{'libVersion': 50727438, 'checkedVersion': 0, 'ma3xVoices': 64, 'numChannels': 2, 'sampleRate': 22050, 'mixBufferSize': 128, 'filterEnabled': 1, 'buildTimeStamp': 1195621085, 'buildGUID': b'1feda229-b9a8-45e9-96f4-73c0a80e7220'}
>>> midi.volume
90
>>> midi.volume = 70 # Set master volume
>>> midi.reverb = ReverbPreset.LARGE_HALL # Enable reverb effect
>>> midi.write([0x90, 60, 127]) # On middle C note with maximum velocity
>>> import time ; time.sleep(2)
>>> midi.write([0x80, 60, 127]) # Off middle C note with maximum velocity
# Using helpers
>>> from midistream.helpers import Note, midi_note_on
>>> midi.write(midi_note_on(Note.C4) + midi_note_on(Note.Es5))