"""SoundObject class for spatial audio reproduction."""
import matplotlib
import numpy as np
import pyfar as pf
import sofar as sf
[docs]
class DirectivityMS():
"""Directivity class for FreeFieldDirectivityTF convention."""
data: pf.FrequencyData
receivers: pf.Coordinates
def __init__(self, file_path: str, source_index=0) -> None:
"""Init DirectivityMS.
Parameters
----------
file_path : str
directivity path for sofa file.
source_index : int, optional
source index of directivity, by default 0
"""
sofa = sf.read_sofa(file_path, verbose=False)
self.data = pf.FrequencyData(
sofa.Data_Real[source_index, :] + 1j * sofa.Data_Imag[
source_index, :], sofa.N)
positions = sofa.ReceiverPosition
if positions.ndim > 2:
positions = np.squeeze(positions)
self.receivers = pf.io.io._sofa_pos(
sofa.ReceiverPosition_Type, positions)
if self.receivers.cdim != 1:
raise ValueError(
'DirectivityMS only supports 1D coordinates, '
f'got {self.receivers.cdim}D coordinates. Squeezing did not '
'work.')
[docs]
def get_directivity(
self, source_pos: np.ndarray, source_view: np.ndarray,
source_up: np.ndarray, target_position: np.ndarray,
i_freq: int) -> float:
"""Get Directivity for certain position.
Parameters
----------
source_pos : np.ndarray
cartesian source position in m
source_view : np.ndarray
cartesian source view in m
source_up : np.ndarray
cartesian source up in m
target_position : np.ndarray
cartesian target position in m
i_freq : int
frequency bin index
Returns
-------
float
nearest directivity factor for given position and orientation.
"""
(azimuth_deg, elevation_deg) = _get_metrics(
source_pos, source_view, source_up, target_position)
find = pf.Coordinates.from_spherical_elevation(
azimuth_deg/180*np.pi, elevation_deg/180*np.pi, 1,
)
index, _ = self.receivers.find_nearest(find)
return self.data.freq[index, i_freq]
def _get_metrics(pos_G, view_G, up_G, target_pos_G):
pos_G = np.array(pos_G, dtype=float)
view_G = np.array(view_G, dtype=float)
up_G = np.array(up_G, dtype=float)
target_pos_G = np.array(target_pos_G, dtype=float)
direction_G = target_pos_G - pos_G
x_dash = np.cross(view_G, up_G)
y_dash = up_G
z_dash = -view_G
w_x_local = np.dot(direction_G, x_dash)
w_y_local = np.dot(direction_G, y_dash)
w_z_local = np.dot(direction_G, z_dash)
azimuth_deg = np.arctan2(-w_x_local, -w_z_local) / np.pi * 180
w = np.array([w_x_local, w_y_local, w_z_local])
w_y_local_normalized = w_y_local / np.sqrt(np.dot(w, w))
elevation_deg = np.arcsin(w_y_local_normalized) / np.pi * 180
return (azimuth_deg, elevation_deg)
[docs]
class SoundObject():
"""A class holding the common properties for Source and Receiver."""
position: np.ndarray
view: np.ndarray
up: np.ndarray
def __init__(
self, position: np.ndarray, view: np.ndarray,
up: np.ndarray) -> None:
"""Init a sound object.
Parameters
----------
position : np.ndarray
position of the sound object in m
view : np.ndarray
view vector of sound object
up : np.ndarray
uo vector of sound object
"""
self.position = np.array(position, dtype=float)
assert self.position.shape == (3,)
self.view = np.array(view, dtype=float)
self.view /= np.sqrt(np.dot(view, view))
assert self.view.shape == (3,)
self.up = np.array(up, dtype=float)
self.up /= np.sqrt(np.dot(up, up))
assert self.up.shape == (3,)
[docs]
def plot(self, ax: matplotlib.axes.Axes, **kwargs):
"""Plot SoundObject position and orientation.
Parameters
----------
ax : matplotlib.axes.Axes
Axes to plot on.
**kwargs
Keyword arguments that are passed to
``matplotlib.pyplot.scatter()``.
"""
xyz = self.position
ax.scatter(xyz[0], xyz[1], xyz[2], kwargs)
[docs]
class SoundSource(SoundObject):
"""Acoustic sound source inhered from SoundObject."""
directivity: DirectivityMS
sound_power: float
def __init__(
self, position: np.ndarray, view: np.ndarray,
up: np.ndarray, directivity: DirectivityMS = None,
sound_power: float = 1) -> None:
"""Init sound source.
Parameters
----------
position : np.ndarray
position of the sound source in m
view : np.ndarray
view vector of sound source
up : np.ndarray
uo vector of sound source
directivity : DirectivityMS, optional
Directivity, by default None
sound_power : float, optional
sound power of the source in Watt, by default 1
"""
super(SoundSource, self).__init__(position, view, up)
self.sound_power = float(sound_power)
if directivity is not None:
assert isinstance(directivity, DirectivityMS)
self.directivity = directivity
[docs]
def plot(self, ax, **kwargs):
"""Plot Source position and orientation.
Parameters
----------
ax : matplotlib.axes.Axes
Axes to plot on.
**kwargs
Keyword arguments that are passed to
``matplotlib.pyplot.scatter()``.
"""
super(SoundSource, self).plot(ax, color='r', label='Source', **kwargs)
[docs]
def get_directivity(
self, target_position: np.ndarray, frequency: float) -> float:
"""Get Directivity for certain position and frequency.
Parameters
----------
target_position : np.ndarray
cartesian target position in m of shape (3,) or (n, 3).
frequency : float
frequency in Hz.
Returns
-------
float
nearest directivity factor for given position and frequency.
"""
i_freq = np.argmin(np.abs(self.directivity.data.frequencies-frequency))
if target_position.size == 3:
return self.directivity.get_directivity(
self.position, self.view, self.up, target_position, i_freq)
else:
return np.array([
self.directivity.get_directivity(
self.position, self.view, self.up, pos, i_freq)
for pos in target_position
])[:, 0]
[docs]
class Receiver(SoundObject):
"""Receiver object inhered from SoundObject."""
def __init__(
self, position: np.ndarray, view: np.ndarray,
up: np.ndarray) -> None:
"""Init sound receiver.
Parameters
----------
position : np.ndarray
cartesian positions for receiver.
view : np.ndarray
view vector of sound receiver.
up : np.ndarray
up vector of sound receiver.
"""
super(Receiver, self).__init__(position, view, up)
[docs]
def plot(self, ax, **kwargs):
"""Plot Receiver position and orientation.
Parameters
----------
ax : matplotlib.axes.Axes
Axes to plot on.
**kwargs
Keyword arguments that are passed to
``matplotlib.pyplot.scatter()``.
"""
super(Receiver, self).plot(ax, color='b', label='Receiver', **kwargs)
