jackclient¶

Client that dumps samples directly to the jack client with the jack package.

Data:

`SERVER`	After initializing, JackClient will register itself with this variable.
`FS`	Sampling rate of the active server
`BLOCKSIZE`	Blocksize, or the amount of samples processed by jack per each `JackClient.process()` call.
`QUEUE`	Queue to be loaded with frames of BLOCKSIZE audio.
`PLAY`	Event used to trigger loading samples from QUEUE, ie.
`STOP`	Event that is triggered on the end of buffered audio.
`Q_LOCK`	Lock that enforces a single writer to the QUEUE at a time.
`CONTINUOUS`	Event that (when set) signals the sound server should play some sound continuously rather than remain silent by default (eg.
`CONTINUOUS_QUEUE`	Queue that
`CONTINUOUS_LOOP`	Event flag that is set when frames dropped into the CONTINUOUS_QUEUE should be looped (eg.

Classes:

JackClient([name])

Client that dumps frames of audio directly into a running jackd client.

SERVER = None¶

After initializing, JackClient will register itself with this variable.

Type: JackClient

FS = None¶

Sampling rate of the active server

Type: int

BLOCKSIZE = None¶

Blocksize, or the amount of samples processed by jack per each JackClient.process() call.

Type: int

QUEUE = None¶

Queue to be loaded with frames of BLOCKSIZE audio.

Type: multiprocessing.Queue

PLAY = None¶

Event used to trigger loading samples from QUEUE, ie. playing.

Type: multiprocessing.Event

STOP = None¶

Event that is triggered on the end of buffered audio.

Note

NOT an event used to stop audio.

Type: multiprocessing.Event

Q_LOCK = None¶

Lock that enforces a single writer to the QUEUE at a time.

Type: multiprocessing.Lock

CONTINUOUS = None¶

Event that (when set) signals the sound server should play some sound continuously rather than remain silent by default (eg. play a background sound).

Type: multiprocessing.Event

CONTINUOUS_QUEUE = None¶

Queue that

Type: multiprocessing.Queue

CONTINUOUS_LOOP = None¶

Event flag that is set when frames dropped into the CONTINUOUS_QUEUE should be looped (eg. in the case of stationary background noise), otherwise they are played and then discarded (ie. the sound is continuously generating and submitting samples)

Type: multiprocessing.Event

class JackClient(name='jack_client')[source]¶

Bases: multiprocessing.context.Process

Client that dumps frames of audio directly into a running jackd client.

When first initialized, sets module level variables above.

Variables

name (str) – name of client, default “jack_client”
q (Queue) – Queue that stores buffered frames of audio
q_lock (Lock) – Lock that manages access to the Queue
play_evt (multiprocessing.Event) – Event used to trigger loading samples from QUEUE, ie. playing.
stop_evt (multiprocessing.Event) – Event that is triggered on the end of buffered audio.
quit_evt (multiprocessing.Event) – Event that causes the process to be terminated.
client (jack.Client) – Client to interface with jackd
blocksize (int) – The blocksize - ie. samples processed per JackClient.process() call.
fs (int) – Sampling rate of client
zero_arr (numpy.ndarray) – cached array of zeroes used to fill jackd pipe when not processing audio.
continuous_cycle (itertools.cycle) – cycle of frames used for continuous sounds

Parameters

name

Methods:

`boot_server`()	Called by `JackClient.run()` to boot the server upon starting the process.
`run`()	Start the process, boot the server, start processing frames and wait for the end.
`quit`()	Set the `JackClient.quit_evt`
`process`(frames)	Process a frame of audio.

boot_server()[source]¶

Called by JackClient.run() to boot the server upon starting the process.

Activates the client and connects it to the number of outports determined by prefs.NCHANNELS

jack.Client s can’t be kept alive, so this must be called just before processing sample starts.

run()[source]¶: Start the process, boot the server, start processing frames and wait for the end.

quit()[source]¶: Set the JackClient.quit_evt

process(frames)[source]¶

Process a frame of audio.

If the JackClient.play_evt is not set, fill port buffers with zeroes.

Otherwise, pull frames of audio from the JackClient.q until it’s empty.

When it’s empty, set the JackClient.stop_evt and clear the JackClient.play_evt .

Warning

Handling multiple outputs is a little screwy right now. v0.2 effectively only supports one channel output.

Parameters: frames – number of frames (samples) to be processed. unused. passed by jack client