Events

class alsa_midi.Event(type=None, *, flags=0, tag=0, queue_id=None, time=None, tick=None, source=None, dest=None, relative=None, raw_data=None)[source]

Base class for ALSA sequencer events.

Normally not instantiated directly – specialized subclasses will be used.

Most attributes are optional – when not set some defaults will be used when passing this to ALSA. time and tick cannot be ever be both set.

Contains python representation of ALSA snd_seq_event_t.

Parameters

event – event type
flags (Optional[EventFlags]) – event flags
tag (int) – event tag
queue_id (Optional[int]) – queue id for the event. None for direct dispatch.
time (Optional[RealTime]) – event time in seconds and nanoseconds
tick (Optional[int]) – event time in MIDI ticks
source (Optional[Address]) – event source address
dest (Optional[Address]) – event destination address
relative (Optional[bool]) – When true then tick or tick are relative
raw_data (Optional[bytes]) – Unparsed raw data part of the ALSA event. Note: this is not MIDI data.
type (Optional[EventType]) –

Variables

event – event type
flags – event flags
tag – event tag
queue_id – queue id for the event. None for direct dispatch.
time – event time in seconds and nanoseconds
tick – event time in MIDI ticks
source – event source address
dest – event destination address
relative – When true then tick or tick are relative
raw_data – Unparsed raw data part of the ALSA event. Note: this is not MIDI data.

length()[source]

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.EventType(value)[source]

Event type values.

BOUNCE = 131

CHANPRESS = 12

CLIENT_CHANGE = 62

CLIENT_EXIT = 61

CLIENT_START = 60

CLOCK = 36

CONTINUE = 31

CONTROL14 = 14

CONTROLLER = 10

ECHO = 50

KEYPRESS = 8

KEYSIGN = 24

NONE = 255

NONREGPARAM = 15

NOTE = 5

NOTEOFF = 7

NOTEON = 6

OSS = 51

PGMCHANGE = 11

PITCHBEND = 13

PORT_CHANGE = 65

PORT_EXIT = 64

PORT_START = 63

PORT_SUBSCRIBED = 66

PORT_UNSUBSCRIBED = 67

QFRAME = 22

QUEUE_SKEW = 38

REGPARAM = 16

RESET = 41

RESULT = 1

SENSING = 42

SETPOS_TICK = 33

SETPOS_TIME = 34

SONGPOS = 20

SONGSEL = 21

START = 30

STOP = 32

SYNC_POS = 39

SYSEX = 130

SYSTEM = 0

TEMPO = 35

TICK = 37

TIMESIGN = 23

TUNE_REQUEST = 40

USR0 = 90

USR1 = 91

USR2 = 92

USR3 = 93

USR4 = 94

USR5 = 95

USR6 = 96

USR7 = 97

USR8 = 98

USR9 = 99

USR_VAR0 = 135

USR_VAR1 = 136

USR_VAR2 = 137

USR_VAR3 = 138

USR_VAR4 = 139

class alsa_midi.EventFlags(value)[source]

Event flags.

EVENT_LENGTH_FIXED = 0

EVENT_LENGTH_MASK = 12

EVENT_LENGTH_VARIABLE = 4

EVENT_LENGTH_VARUSR = 8

PRIORITY_HIGH = 16

PRIORITY_MASK = 16

PRIORITY_NORMAL = 0

TIME_MODE_ABS = 0

TIME_MODE_MASK = 2

TIME_MODE_REL = 2

TIME_STAMP_MASK = 1

TIME_STAMP_REAL = 1

TIME_STAMP_TICK = 0

class alsa_midi.NoteEvent(note, channel=0, velocity=127, duration=0, off_velocity=0, **kwargs)[source]

Note event – a Note On followed by a Note Off.

Parameters

note (int) – MIDI note number
channel (int) – MIDI channel
velocity (int) – note velocity
duration (int) – note duration
off_velocity (int) – Note Off velocity

Variables

note – MIDI note number
channel – MIDI channel
velocity – note velocity
duration – note duration
off_velocity – Note Off velocity

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.NoteOnEvent(note, channel=0, velocity=127, **kwargs)[source]

Note On event.

Parameters

note (int) – MIDI note number
channel (int) – MIDI channel
velocity (int) – note velocity

Variables

note – MIDI note number
channel – MIDI channel
velocity – note velocity

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.NoteOffEvent(note, channel=0, velocity=127, **kwargs)[source]

Note Off event.

Parameters

note (int) – MIDI note number
channel (int) – MIDI channel
velocity (int) – note velocity

Variables

note – MIDI note number
channel – MIDI channel
velocity – note velocity

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.KeyPressureEvent(note, channel=0, velocity=127, **kwargs)[source]

Key pressure changed (aftertouch) event.

Parameters

note (int) – MIDI note number
channel (int) – MIDI channel
velocity (int) – note velocity

Variables

note – MIDI note number
channel – MIDI channel
velocity – note velocity

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.ControlChangeEvent(channel, param, value, **kwargs)[source]

Control Change event.

Parameters

channel (int) – MIDI channel
param (int) – parameter number
value (int) – new value

Variables

channel – MIDI channel
param – parameter number
value – new value

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.ProgramChangeEvent(channel, value, **kwargs)[source]

Program Change event.

Parameters

channel (int) – MIDI channel
value (int) – new value

Variables

channel – MIDI channel
value – new value

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.ChannelPressureEvent(channel, value, **kwargs)[source]

Channel Pressure event.

Parameters

channel (int) – MIDI channel
value (int) – new value

Variables

channel – MIDI channel
value – new value

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.PitchBendEvent(channel, value, **kwargs)[source]

Pitch Bend event.

Parameters

channel (int) – MIDI channel
value (int) – new value

Variables

channel – MIDI channel
value – new value

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.Control14BitChangeEvent(channel, param, value, **kwargs)[source]

14-bit Control Change event.

Parameters

channel (int) – MIDI channel
param (int) – parameter number
value (int) – new value

Variables

channel – MIDI channel
param – parameter number
value – new value

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.NonRegisteredParameterChangeEvent(channel, param, value, **kwargs)[source]

Non Registered Parameter Change event.

Parameters

channel (int) – MIDI channel
param (int) – parameter number
value (int) – new value

Variables

channel – MIDI channel
param – parameter number
value – new value

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.RegisteredParameterChangeEvent(channel, param, value, **kwargs)[source]

Registered Parameter Change event.

Parameters

channel (int) – MIDI channel
param (int) – parameter number
value (int) – new value

Variables

channel – MIDI channel
param – parameter number
value – new value

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.SongPositionPointerEvent(channel, value, **kwargs)[source]

Song Position Pointer event.

Parameters

channel (int) – MIDI channel
value (int) – new value

Variables

channel – MIDI channel
value – new value

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.SongSelectEvent(channel, value, **kwargs)[source]

Song Select event.

Parameters

channel (int) – MIDI channel
value (int) – new value

Variables

channel – MIDI channel
value – new value

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.TimeSignatureEvent(channel, value, **kwargs)[source]

Time Signature event.

Parameters

channel (int) – MIDI channel
value (int) – new value

Variables

channel – MIDI channel
value – new value

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.KeySignatureEvent(channel, value, **kwargs)[source]

Key Signature event.

Parameters

channel (int) – MIDI channel
value (int) – new value

Variables

channel – MIDI channel
value – new value

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.StartEvent(control_queue=None, **kwargs)[source]

Start event.

Parameters: control_queue (Optional[int]) – affected queue
Variables: control_queue – affected queue id

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.ContinueEvent(control_queue=None, **kwargs)[source]

Continue event.

Parameters: control_queue (Optional[int]) – affected queue
Variables: control_queue – affected queue id

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.StopEvent(control_queue=None, **kwargs)[source]

Stop event.

Parameters: control_queue (Optional[int]) – affected queue
Variables: control_queue – affected queue id

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.SetQueuePositionTickEvent(position, *args, **kwargs)[source]

Set Queue Position Tick event.

Parameters

control_queue – affected queue
position (int) – new position

Variables

control_queue – affected queue id
position – new position

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.SetQueuePositionTimeEvent(position, *args, **kwargs)[source]

Set Queue Position Time event.

Parameters

control_queue – affected queue
position (RealTime) – new position

Variables

control_queue – affected queue id
position – new position

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.SetQueueTempoEvent(midi_tempo=None, *, bpm=None, **kwargs)[source]

Set Queue Position Time event.

Parameters

control_queue – affected queue
midi_tempo (int) – MIDI tempo (microseconds per quarter note)
bpm (float) – beats per minute as an alternative to midi_tempo

Variables

control_queue – affected queue id
midi_tempo – MIDI tempo (microseconds per quarter note)

property bpm: Approximate beats per minute value for the selected tempo.

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.ClockEvent(control_queue=None, **kwargs)[source]

MIDI Clock event.

Parameters: control_queue (Optional[int]) – affected queue
Variables: control_queue – affected queue id

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.TickEvent(control_queue=None, **kwargs)[source]

MIDI Tick event.

Parameters: control_queue (Optional[int]) – affected queue
Variables: control_queue – affected queue id

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.QueueSkewEvent(value, base, *args, **kwargs)[source]

Queue Skew event.

Parameters

control_queue – affected queue
value (int) – skew value
base (int) – skew base

Variables

control_queue – affected queue id
value – skew value
base – skew base

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.SyncPositionChangedEvent(position, *args, **kwargs)[source]

Sync Position Changed event.

Parameters

control_queue – affected queue
position (int) – new position

Variables

control_queue – affected queue id
position – new position

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.TuneRequestEvent(type=None, *, flags=0, tag=0, queue_id=None, time=None, tick=None, source=None, dest=None, relative=None, raw_data=None)[source]

Tune request event.

Normally not instantiated directly – specialized subclasses will be used.

Most attributes are optional – when not set some defaults will be used when passing this to ALSA. time and tick cannot be ever be both set.

Contains python representation of ALSA snd_seq_event_t.

Parameters

event – event type
flags (Optional[EventFlags]) – event flags
tag (int) – event tag
queue_id (Optional[int]) – queue id for the event. None for direct dispatch.
time (Optional[RealTime]) – event time in seconds and nanoseconds
tick (Optional[int]) – event time in MIDI ticks
source (Optional[Address]) – event source address
dest (Optional[Address]) – event destination address
relative (Optional[bool]) – When true then tick or tick are relative
raw_data (Optional[bytes]) – Unparsed raw data part of the ALSA event. Note: this is not MIDI data.
type (Optional[EventType]) –

Variables

event – event type
flags – event flags
tag – event tag
queue_id – queue id for the event. None for direct dispatch.
time – event time in seconds and nanoseconds
tick – event time in MIDI ticks
source – event source address
dest – event destination address
relative – When true then tick or tick are relative
raw_data – Unparsed raw data part of the ALSA event. Note: this is not MIDI data.

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.ResetEvent(type=None, *, flags=0, tag=0, queue_id=None, time=None, tick=None, source=None, dest=None, relative=None, raw_data=None)[source]

Reset event.

Normally not instantiated directly – specialized subclasses will be used.

Most attributes are optional – when not set some defaults will be used when passing this to ALSA. time and tick cannot be ever be both set.

Contains python representation of ALSA snd_seq_event_t.

Parameters

event – event type
flags (Optional[EventFlags]) – event flags
tag (int) – event tag
queue_id (Optional[int]) – queue id for the event. None for direct dispatch.
time (Optional[RealTime]) – event time in seconds and nanoseconds
tick (Optional[int]) – event time in MIDI ticks
source (Optional[Address]) – event source address
dest (Optional[Address]) – event destination address
relative (Optional[bool]) – When true then tick or tick are relative
raw_data (Optional[bytes]) – Unparsed raw data part of the ALSA event. Note: this is not MIDI data.
type (Optional[EventType]) –

Variables

event – event type
flags – event flags
tag – event tag
queue_id – queue id for the event. None for direct dispatch.
time – event time in seconds and nanoseconds
tick – event time in MIDI ticks
source – event source address
dest – event destination address
relative – When true then tick or tick are relative
raw_data – Unparsed raw data part of the ALSA event. Note: this is not MIDI data.

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.ActiveSensingEvent(type=None, *, flags=0, tag=0, queue_id=None, time=None, tick=None, source=None, dest=None, relative=None, raw_data=None)[source]

Active Sensing event.

Normally not instantiated directly – specialized subclasses will be used.

Most attributes are optional – when not set some defaults will be used when passing this to ALSA. time and tick cannot be ever be both set.

Contains python representation of ALSA snd_seq_event_t.

Parameters

event – event type
flags (Optional[EventFlags]) – event flags
tag (int) – event tag
queue_id (Optional[int]) – queue id for the event. None for direct dispatch.
time (Optional[RealTime]) – event time in seconds and nanoseconds
tick (Optional[int]) – event time in MIDI ticks
source (Optional[Address]) – event source address
dest (Optional[Address]) – event destination address
relative (Optional[bool]) – When true then tick or tick are relative
raw_data (Optional[bytes]) – Unparsed raw data part of the ALSA event. Note: this is not MIDI data.
type (Optional[EventType]) –

Variables

event – event type
flags – event flags
tag – event tag
queue_id – queue id for the event. None for direct dispatch.
time – event time in seconds and nanoseconds
tick – event time in MIDI ticks
source – event source address
dest – event destination address
relative – When true then tick or tick are relative
raw_data – Unparsed raw data part of the ALSA event. Note: this is not MIDI data.

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.EchoEvent(type=None, *, flags=0, tag=0, queue_id=None, time=None, tick=None, source=None, dest=None, relative=None, raw_data=None)[source]

Echo event.

Normally not instantiated directly – specialized subclasses will be used.

Most attributes are optional – when not set some defaults will be used when passing this to ALSA. time and tick cannot be ever be both set.

Contains python representation of ALSA snd_seq_event_t.

Parameters

event – event type
flags (Optional[EventFlags]) – event flags
tag (int) – event tag
queue_id (Optional[int]) – queue id for the event. None for direct dispatch.
time (Optional[RealTime]) – event time in seconds and nanoseconds
tick (Optional[int]) – event time in MIDI ticks
source (Optional[Address]) – event source address
dest (Optional[Address]) – event destination address
relative (Optional[bool]) – When true then tick or tick are relative
raw_data (Optional[bytes]) – Unparsed raw data part of the ALSA event. Note: this is not MIDI data.
type (Optional[EventType]) –

Variables

event – event type
flags – event flags
tag – event tag
queue_id – queue id for the event. None for direct dispatch.
time – event time in seconds and nanoseconds
tick – event time in MIDI ticks
source – event source address
dest – event destination address
relative – When true then tick or tick are relative
raw_data – Unparsed raw data part of the ALSA event. Note: this is not MIDI data.

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.OSSEvent(type=None, *, flags=0, tag=0, queue_id=None, time=None, tick=None, source=None, dest=None, relative=None, raw_data=None)[source]

OSS emulation event.

Normally not instantiated directly – specialized subclasses will be used.

Most attributes are optional – when not set some defaults will be used when passing this to ALSA. time and tick cannot be ever be both set.

Contains python representation of ALSA snd_seq_event_t.

Parameters

event – event type
flags (Optional[EventFlags]) – event flags
tag (int) – event tag
queue_id (Optional[int]) – queue id for the event. None for direct dispatch.
time (Optional[RealTime]) – event time in seconds and nanoseconds
tick (Optional[int]) – event time in MIDI ticks
source (Optional[Address]) – event source address
dest (Optional[Address]) – event destination address
relative (Optional[bool]) – When true then tick or tick are relative
raw_data (Optional[bytes]) – Unparsed raw data part of the ALSA event. Note: this is not MIDI data.
type (Optional[EventType]) –

Variables

event – event type
flags – event flags
tag – event tag
queue_id – queue id for the event. None for direct dispatch.
time – event time in seconds and nanoseconds
tick – event time in MIDI ticks
source – event source address
dest – event destination address
relative – When true then tick or tick are relative
raw_data – Unparsed raw data part of the ALSA event. Note: this is not MIDI data.

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.ClientStartEvent(addr, **kwargs)[source]

Client start event.

Parameters: addr (Address) – sequencer address
Variables: addr – sequencer address

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.ClientExitEvent(addr, **kwargs)[source]

Client exit event.

Parameters: addr (Address) – sequencer address
Variables: addr – sequencer address

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.ClientChangeEvent(addr, **kwargs)[source]

Client change event.

Parameters: addr (Address) – sequencer address
Variables: addr – sequencer address

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.PortStartEvent(addr, **kwargs)[source]

Port start event.

Parameters: addr (Address) – sequencer address
Variables: addr – sequencer address

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.PortExitEvent(addr, **kwargs)[source]

Port exit event.

Parameters: addr (Address) – sequencer address
Variables: addr – sequencer address

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.PortChangeEvent(addr, **kwargs)[source]

Port change event.

Parameters: addr (Address) – sequencer address
Variables: addr – sequencer address

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.PortSubscribedEvent(connect_sender, connect_dest, **kwargs)[source]

Port subscribed event.

Parameters

sender – sender address
dest – destination address
connect_sender (Address) –
connect_dest (Address) –

Variables

sender – sender address
dest – destination address

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.PortUnsubscribedEvent(connect_sender, connect_dest, **kwargs)[source]

Port unsubscribed event.

Parameters

sender – sender address
dest – destination address
connect_sender (Address) –
connect_dest (Address) –

Variables

sender – sender address
dest – destination address

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.SysExEvent(data, **kwargs)[source]

System Exclusive message event.

Parameters: data (bytes) – the data
Variables: data – the data

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.BounceEvent(data, **kwargs)[source]

Error event.

Parameters: data (bytes) – the data
Variables: data – the data

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.SystemEvent(event, result, **kwargs)[source]

System status event.

Parameters

event (int) – event
result (int) – result

Variables

event – event
result – result

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.ResultEvent(event, result, **kwargs)[source]

Returned result status event.

Parameters

event (int) – event
result (int) – result

Variables

event – event
result – result

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.UserVar0Event(data, **kwargs)[source]

USR_VAR0 event.

Parameters: data (bytes) – the data
Variables: data – the data

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.UserVar1Event(data, **kwargs)[source]

USR_VAR1 event.

Parameters: data (bytes) – the data
Variables: data – the data

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.UserVar2Event(data, **kwargs)[source]

USR_VAR2 event.

Parameters: data (bytes) – the data
Variables: data – the data

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.UserVar3Event(data, **kwargs)[source]

USR_VAR3 event.

Parameters: data (bytes) – the data
Variables: data – the data

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().

class alsa_midi.MidiBytesEvent(midi_bytes, **kwargs)[source]

Pseudo ALSA event to hold MIDI messages as byte sequences.

Used to interface code that operates on MIDI bytes.

Parameters

midi_bytes (bytes) – the MIDI message
kwargs – Event constructor parameters

Variables

midi_bytes – the MIDI message

length()

Calculates the (encoded) byte-stream size of the event.

Wraps snd_seq_event_length().