Queues
- class alsa_midi.Queue(client, queue_id, *, _own=None)[source]
Sequencer queue.
- Variables
client – client object this queue belongs to
queue_id – queue identifier
_own – Ownership flag. True for queues owned by the client, False
- Parameters
client (SequencerClientBase) –
queue_id (int) –
_own (bool) –
for queues owned by other client and None for no ownership management (no release or free on close).
- close()[source]
Close the queue, freeing any resources.
Wraps snd_seq_free_queue().
- continue_()[source]
Continue running the queue.
drain_output()
needs to be called for actual effect.
- control(event_type, value=0)[source]
Queue control (start/stop/continue).
Creates and sends (to the output buffer) queue control event.
drain_output()
needs to be called for the event to actually be sent and executed.Wraps snd_seq_control_queue().
- get_info()[source]
Obtain queue attributes.
Wraps snd_seq_get_queue_info().
- Return type
- get_status()[source]
Obtain queue attributes.
Wraps snd_seq_get_queue_status().
- Return type
- get_tempo()[source]
Get the tempo of the queue.
Wraps snd_seq_get_queue_tempo().
- get_timer()[source]
Obtain queue timer parameters.
Wraps snd_seq_get_queue_timer().
- Return type
- get_usage()[source]
Get the queue usage flag.
Wraps snd_seq_get_queue_usage().
- Returns
True if the queue is considered in use by the current client.
- Return type
- set_info(info)[source]
Change queue attributes.
- Parameters
info (QueueInfo) – new values
Wraps snd_seq_set_queue_info().
- set_tempo(tempo=None, ppq=None, skew=None, skew_base=None, bpm=None)[source]
Set the tempo of the queue.
- Parameters
tempo (Optional[Union[int, QueueTempo]]) – MIDI tempo – microseconds per quarter note
ppq (Optional[int]) – MIDI pulses per quarter note (default: 96)
skew – timer skew value
skew_base – timer skew base value
Wraps snd_seq_set_queue_tempo().
- set_timer(timer)[source]
Change queue timer parameters.
Wraps snd_seq_get_queue_timer().
- Parameters
timer (QueueTimer) –
- set_usage(usage)[source]
Marks the queue in use by the current client.
Wraps snd_seq_set_queue_usage().
This flag is normally automatically managed for
Queue
objects obtained viaSequencerClient
.- Parameters
usage (bool) – True to enable queue usage
- start()[source]
Start the queue.
drain_output()
needs to be called for actual effect.
- stop()[source]
Stop the queue.
drain_output()
needs to be called for actual effect.
- class alsa_midi.QueueInfo(queue_id=0, name='', owner=0, locked=False, flags=0)[source]
Sequencer queue information.
Represents snd_seq_queue_info_t.
- Parameters
- Variables
queue_id – queue identifier
name – queue name
owner – client id of the queue owner
locked – queue locked flag
flags – conditional bit flags
- Return type
- class alsa_midi.QueueStatus(queue_id=0, events=0, tick_time=0, real_time=RealTime(seconds=0, nanoseconds=0), status=0)[source]
Queue status.
Represents data from snd_seq_queue_status_t
- Variables
queue_id – queue id
events – number of events
tick_time – queue time in ticks
real_time – queue time in seconds and nanoseconds
status – running status bits
- Parameters
- Return type
- property running
Whether the queue is running.
- class alsa_midi.QueueTempo(tempo=500000, ppq=96, skew=None, skew_base=None)[source]
Queue tempo.
Represents data from snd_seq_queue_tempo_t
- Parameters
- Variables
tempo – MIDI tempo (microseconds per quarter note)
ppq – MIDI pulses per quarter note
skew – timer skew value
skew_base – timer skew base value (only allowed value is 0x10000).
- Return type
- property bpm
Approximate beats per minute value for the selected tempo.
- class alsa_midi.QueueTimer(id=TimerId(dev_class=0, dev_sclass=0, card=0, device=0, subdevice=0), queue_id=0, type=QueueTimerType.ALSA, resolution=0)[source]
Queue timer.
Represents data from snd_seq_queue_timer_t
- Parameters
id (TimerId) – timer device identification
queue_id (int) – queue id
type (QueueTimerType) – timer type
resolution (int) – timer resolution
- Variables
id – timer device identification
queue_id – queue id
type – timer type
resolution – timer resolution
- Return type
- class alsa_midi.queue.TimerId(dev_class, dev_sclass, card, device, subdevice)[source]
Queue timer identification (named tuple).
Points to a specific timer device.
- Variables
dev_class – timer class
dev_sclass – timer subclass
card – timer card
device – timer device
subdevice – timer subdevice
- Parameters