`TimeSamplesPlayback`#

class spectacoular.lprocess.TimeSamplesPlayback(*args, **kwargs)

Bases: TimeOut, BaseSpectacoular

Naive class implementation to allow audio playback of .h5 file contents.

The class uses the devices available to the sounddevice library for audio playback. Input and output devices can be listed by

>>> import sounddevice
>>> sounddevice.query_devices()

In the future, this class should work in buffer mode and also write the current frame that is played to a class attribute.

digest: A unique identifier for the generator, based on its properties. (read-only)

channels: list containing indices of the channels to be played back.

device: two-element list containing indices of input and output device to be used for audio playback.

trait_widget_mapper: ClassVar[dict[str, type]]: dictionary containing the mapping between a class trait attribute and a Bokeh widget. Keys: name of the trait attribute. Values: Bokeh widget.

trait_widget_args: ClassVar[dict[str, dict[str, object]]]: dictionary containing arguments that belongs to a widget that is created from a trait attribute and should be considered when the widget is built. For example: {“traitname”:{‘disabled’:True,’background_color’:’red’,…}}.

play(): Play normalized audio from the source channels in channels.

stop(): Stop audio playback of the file content.

result(num): Yield the output block-wise.

get_widgets(trait_widget_mapper=None, trait_widget_args=None)

Create a mapping between several class trait attributes and Bokeh widgets.

This function is implemented in all SpectAcoular classes and is added to Acoular’s classes via the bokehview module. For each attribute provided, it builds a corresponding Bokeh widget.

The function handles multiple cases of View construction:

Default View: the function is called as a method by a BaseSpectacoular derived instance without specifying trait_widget_mapper and trait_widget_args explicitly as function arguments. In this case, the default widget mapping, defined in bokehview, will be used:
```
from spectacoular import RectGrid
from bokeh.io import show
from bokeh.layouts import gridplot

grid = RectGrid()

widgets = list(grid.get_widgets().values())
show(gridplot(widgets, ncols=5, sizing_mode='stretch_both'))
```
No Predefined View: get_widgets() is called and a HasTraits derived instance is given as the first argument to the function without any further arguments. In this case, a default mapping is created from all editable traits to create the view.

from acoular import RectGrid
from spectacoular import get_widgets
from bokeh.io import show
from bokeh.layouts import gridplot

grid = RectGrid()

widgets = list(get_widgets(grid).values())
show(gridplot(widgets, ncols=5, sizing_mode='stretch_both'))

Custom View: get_widgets() is called by a BaseSpectacoular derived instance and an explicit mapping is given. In this case, the instance attributes (self.trait_widget_mapper, self.trait_widget_args) are superseded.

from spectacoular import RectGrid
from bokeh.io import show
from bokeh.models.widgets import Slider
from bokeh.layouts import column

grid = RectGrid()

trait_widget_mapper = {'x_min': Slider}
trait_widget_args = {'x_min': {'title': 'X Min', 'start': -1, 'end': 1, 'step':0.1}}

widgets = list(grid.get_widgets(
      trait_widget_mapper=trait_widget_mapper,
      trait_widget_args=trait_widget_args
).values())
show(column(widgets,sizing_mode='stretch_both'))

The same functionality can also be used with HasTraits-derived classes that are not part of SpectAcoular:

from acoular import RectGrid
from spectacoular import get_widgets
from bokeh.io import show
from bokeh.models.widgets import Slider
from bokeh.layouts import column

grid = RectGrid()

trait_widget_mapper = {'x_min': Slider}
trait_widget_args = {'x_min': {'title': 'X Min', 'start': -1, 'end': 1, 'step':0.1}}

widgets = list(get_widgets(grid,
      trait_widget_mapper=trait_widget_mapper,
      trait_widget_args=trait_widget_args
).values())
show(column(widgets,sizing_mode='stretch_both'))

Parameters:

trait_widget_mapperdict, optional

contains the desired mapping of a variable name (dict key) to a Bokeh widget type (dict value), by default {}

trait_widget_argsdict, optional

contains the desired widget kwargs (dict values) for each variable name (dict key),: by default {}

Returns:

dict: A dictionary containing the variable names as the key and the Bokeh widget instance as value.

set_widgets(**kwargs)

Set instances of Bokeh widgets to certain trait attributes.

This function is implemented in all SpectAcoular classes and is added to Acoular’s classes in bokehview.py. It allows to reference an existing widget to a certain class trait attribute. Expects a class traits name as parameter and the widget instance as value.

For example:

>>> from spectacoular import RectGrid
>>> from bokeh.models.widgets import Select
>>>
>>> rg = RectGrid()
>>> sl = Select(value='10.0')
>>> rg.set_widgets(x_max=sl)

The value of the trait attribute changes to the widgets value when it is different.

Parameters:

**kwargs: The name of the class trait attributes. Depends on the class.

Returns:

None.

source: Data source; Generator or derived object.

sample_freq: Sampling frequency of output signal, as given by source.

num_channels: Number of channels in output, as given by source.

num_samples: Number of samples in output, as given by source.

TimeSamplesPlayback#

`TimeSamplesPlayback`#