Ports

class alsa_midi.Port(client, port_id)

Sequencer port.

Variables

• client – the client object this port belongs to

• client_id – client identifier

• port_id – port identifier

Parameters

• client (SequencerClientBase) –

• port_id (int) –

close()

Close the port, freeing any resources.

Wraps snd_seq_delete_simple_port().

connect_from(src)

Connect another port to this one.

Parameters

src (Union[Address, Port, PortInfo, Tuple[int, int]]) – source port

Wraps snd_seq_connect_from().

connect_to(dest)

Connect port to another one.

Parameters

dest (Union[Address, Port, PortInfo, Tuple[int, int]]) – destination port

Wraps snd_seq_connect_to().

disconnect_from(src)

Disconnect another port from this one.

Parameters

src (Union[Address, Port, PortInfo, Tuple[int, int]]) – source port

Wraps snd_seq_disconnect_from().

disconnect_to(dest)

Disconnect port from another one.

Parameters

dest (Union[Address, Port, PortInfo, Tuple[int, int]]) – destination port

Wraps snd_seq_disconnect_to().

get_info()

Get information about the port.

Wraps snd_seq_get_port_info().

Return type

PortInfo

list_subscribers(type=None)

Lists subscribers accessing a port.

Wraps snd_seq_query_port_subscribers().

Parameters

type (SubscriptionQueryType) – limit query to the specific type

Return type

List[SubscriptionQuery]

set_info(info)

Update information about the port.

Wraps snd_seq_set_port_info().

Parameters

info (PortInfo) –

class alsa_midi.PortInfo(client_id=0, port_id=None, name='', capability=PortCaps._NONE, type=PortType.ANY, midi_channels=0, midi_voices=0, synth_voices=0, read_use=0, write_use=0, port_specified=None, timestamping=False, timestamp_real=False, timestamp_queue_id=0)

Sequencer port information.

Variables

• client_id – client identifier

• port_id – port identifier

• name – port name

• capability – port capabilities

• type – port type

• midi_channels – number of MIDI channels

• midi_voices – number of MIDI voices

• synth_voices – number of synth voices

• read_use – number of readers

• write_use – number of writers

• timestamping – enable time stamping

• timestamp_real – use real time (not MIDI ticks) for time stamping

• timestamp_queue_id – queue used for timestamping

• client_name – client name. Set only when list_ports() was used to obtain this information.

Parameters

• client_id (int) –

• port_id (Optional[int]) –

• name (str) –

• capability (PortCaps) –

• type (PortType) –

• midi_channels (int) –

• midi_voices (int) –

• synth_voices (int) –

• read_use (int) –

• write_use (int) –

• port_specified (dataclasses.InitVar[Optional[bool]]) –

• timestamping (bool) –

• timestamp_real (bool) –

• timestamp_queue_id (int) –

Return type

None

Represents snd_seq_port_info_t with extra optional client_name attribute added when created by list_ports().

class alsa_midi.PortCaps(value)

Port capability flags.

DUPLEX = 16

NO_EXPORT = 128

READ = 1

SUBS_READ = 32

SUBS_WRITE = 64

SYNC_READ = 4

SYNC_WRITE = 8

WRITE = 2

alsa_midi.READ_PORT = PortCaps.READ | PortCaps.SUBS_READ

Port capability flags.

alsa_midi.WRITE_PORT = PortCaps.WRITE | PortCaps.SUBS_WRITE

Port capability flags.

alsa_midi.RW_PORT = PortType.MIDI_GENERIC | PortType.SOFTWARE

Port capability flags.

class alsa_midi.PortType(value)

Port type flags.

ANY = 0

APPLICATION = 1048576

DIRECT_SAMPLE = 2048

HARDWARE = 65536

MIDI_GENERIC = 2

MIDI_GM = 4

MIDI_GM2 = 64

MIDI_GS = 8

MIDI_MT32 = 32

MIDI_XG = 16

PORT = 524288

SAMPLE = 4096

SOFTWARE = 131072

SPECIFIC = 1

SYNTH = 1024

SYNTHESIZER = 262144

class alsa_midi.SubscriptionQuery(root=Address(client_id=0, port_id=0), type=SubscriptionQueryType.READ, index=0, num_subs=0, addr=Address(client_id=0, port_id=0), queue_id=0, exclusive=False, time_update=False, time_real=False)

Port subscription (connection) information.

Represents data from snd_seq_query_subscribe_t

Parameters

• root (Address) – address of the port queried

• type (SubscriptionQueryType) – either SubscriptionQueryType.READ or SubscriptionQueryType.WRITE

• index (int) – subscription index inside query result

• num_subs (int) – number of subscription in query result

• addr (Address) – address of the subscriber

• queue_id (int) – queue id

• exclusive (bool) – exclusive access

• time_update (bool) – time update enabled

• time_real (bool) – user real time stamps

Variables

• root – address of the port queried

• type – either SubscriptionQueryType.READ or SubscriptionQueryType.WRITE

• index – subscription index inside query result

• num_subs – number of subscription in query result

• addr – address of the subscriber

• queue_id – queue id

• exclusive – exclusive access

• time_update – time update enabled

• time_real – user real time stamps

Return type

None

class alsa_midi.SubscriptionQueryType(value)

An enumeration.

READ = 0

WRITE = 1