yourusername's picture
:beers: cheers
66a6dc0
import torch
import numpy as np
import scipy.signal
from numba import jit
from deepafx_st.processors.processor import Processor
@jit(nopython=True)
def biqaud(
gain_dB: float,
cutoff_freq: float,
q_factor: float,
sample_rate: float,
filter_type: str,
):
"""Use design parameters to generate coeffieicnets for a specific filter type.
Args:
gain_dB (float): Shelving filter gain in dB.
cutoff_freq (float): Cutoff frequency in Hz.
q_factor (float): Q factor.
sample_rate (float): Sample rate in Hz.
filter_type (str): Filter type.
One of "low_shelf", "high_shelf", or "peaking"
Returns:
b (np.ndarray): Numerator filter coefficients stored as [b0, b1, b2]
a (np.ndarray): Denominator filter coefficients stored as [a0, a1, a2]
"""
A = 10 ** (gain_dB / 40.0)
w0 = 2.0 * np.pi * (cutoff_freq / sample_rate)
alpha = np.sin(w0) / (2.0 * q_factor)
cos_w0 = np.cos(w0)
sqrt_A = np.sqrt(A)
if filter_type == "high_shelf":
b0 = A * ((A + 1) + (A - 1) * cos_w0 + 2 * sqrt_A * alpha)
b1 = -2 * A * ((A - 1) + (A + 1) * cos_w0)
b2 = A * ((A + 1) + (A - 1) * cos_w0 - 2 * sqrt_A * alpha)
a0 = (A + 1) - (A - 1) * cos_w0 + 2 * sqrt_A * alpha
a1 = 2 * ((A - 1) - (A + 1) * cos_w0)
a2 = (A + 1) - (A - 1) * cos_w0 - 2 * sqrt_A * alpha
elif filter_type == "low_shelf":
b0 = A * ((A + 1) - (A - 1) * cos_w0 + 2 * sqrt_A * alpha)
b1 = 2 * A * ((A - 1) - (A + 1) * cos_w0)
b2 = A * ((A + 1) - (A - 1) * cos_w0 - 2 * sqrt_A * alpha)
a0 = (A + 1) + (A - 1) * cos_w0 + 2 * sqrt_A * alpha
a1 = -2 * ((A - 1) + (A + 1) * cos_w0)
a2 = (A + 1) + (A - 1) * cos_w0 - 2 * sqrt_A * alpha
elif filter_type == "peaking":
b0 = 1 + alpha * A
b1 = -2 * cos_w0
b2 = 1 - alpha * A
a0 = 1 + alpha / A
a1 = -2 * cos_w0
a2 = 1 - alpha / A
else:
pass
# raise ValueError(f"Invalid filter_type: {filter_type}.")
b = np.array([b0, b1, b2]) / a0
a = np.array([a0, a1, a2]) / a0
return b, a
# Adapted from https://github.com/csteinmetz1/pyloudnorm/blob/master/pyloudnorm/iirfilter.py
def parametric_eq(
x: np.ndarray,
sample_rate: float,
low_shelf_gain_dB: float = 0.0,
low_shelf_cutoff_freq: float = 80.0,
low_shelf_q_factor: float = 0.707,
first_band_gain_dB: float = 0.0,
first_band_cutoff_freq: float = 300.0,
first_band_q_factor: float = 0.707,
second_band_gain_dB: float = 0.0,
second_band_cutoff_freq: float = 1000.0,
second_band_q_factor: float = 0.707,
third_band_gain_dB: float = 0.0,
third_band_cutoff_freq: float = 4000.0,
third_band_q_factor: float = 0.707,
fourth_band_gain_dB: float = 0.0,
fourth_band_cutoff_freq: float = 8000.0,
fourth_band_q_factor: float = 0.707,
high_shelf_gain_dB: float = 0.0,
high_shelf_cutoff_freq: float = 1000.0,
high_shelf_q_factor: float = 0.707,
dtype=np.float32,
):
"""Six-band parametric EQ.
Low-shelf -> Band 1 -> Band 2 -> Band 3 -> Band 4 -> High-shelf
Args:
"""
# print(f"autodiff peq fs = {sample_rate}")
# -------- apply low-shelf filter --------
b, a = biqaud(
low_shelf_gain_dB,
low_shelf_cutoff_freq,
low_shelf_q_factor,
sample_rate,
"low_shelf",
)
sos0 = np.concatenate((b, a))
x = scipy.signal.lfilter(b, a, x)
# -------- apply first-band peaking filter --------
b, a = biqaud(
first_band_gain_dB,
first_band_cutoff_freq,
first_band_q_factor,
sample_rate,
"peaking",
)
sos1 = np.concatenate((b, a))
x = scipy.signal.lfilter(b, a, x)
# -------- apply second-band peaking filter --------
b, a = biqaud(
second_band_gain_dB,
second_band_cutoff_freq,
second_band_q_factor,
sample_rate,
"peaking",
)
sos2 = np.concatenate((b, a))
x = scipy.signal.lfilter(b, a, x)
# -------- apply third-band peaking filter --------
b, a = biqaud(
third_band_gain_dB,
third_band_cutoff_freq,
third_band_q_factor,
sample_rate,
"peaking",
)
sos3 = np.concatenate((b, a))
x = scipy.signal.lfilter(b, a, x)
# -------- apply fourth-band peaking filter --------
b, a = biqaud(
fourth_band_gain_dB,
fourth_band_cutoff_freq,
fourth_band_q_factor,
sample_rate,
"peaking",
)
sos4 = np.concatenate((b, a))
x = scipy.signal.lfilter(b, a, x)
# -------- apply high-shelf filter --------
b, a = biqaud(
high_shelf_gain_dB,
high_shelf_cutoff_freq,
high_shelf_q_factor,
sample_rate,
"high_shelf",
)
sos5 = np.concatenate((b, a))
x = scipy.signal.lfilter(b, a, x)
return x.astype(dtype)
class ParametricEQ(Processor):
def __init__(
self,
sample_rate,
min_gain_dB=-24.0,
default_gain_dB=0.0,
max_gain_dB=24.0,
min_q_factor=0.1,
default_q_factor=0.707,
max_q_factor=10,
eps=1e-8,
):
""" """
super().__init__()
self.sample_rate = sample_rate
self.eps = eps
self.ports = [
{
"name": "Lowshelf gain",
"min": min_gain_dB,
"max": max_gain_dB,
"default": default_gain_dB,
"units": "dB",
},
{
"name": "Lowshelf cutoff",
"min": 20.0,
"max": 200.0,
"default": 100.0,
"units": "Hz",
},
{
"name": "Lowshelf Q",
"min": min_q_factor,
"max": max_q_factor,
"default": default_q_factor,
"units": "",
},
{
"name": "First band gain",
"min": min_gain_dB,
"max": max_gain_dB,
"default": default_gain_dB,
"units": "dB",
},
{
"name": "First band cutoff",
"min": 200.0,
"max": 2000.0,
"default": 400.0,
"units": "Hz",
},
{
"name": "First band Q",
"min": min_q_factor,
"max": max_q_factor,
"default": 0.707,
"units": "",
},
{
"name": "Second band gain",
"min": min_gain_dB,
"max": max_gain_dB,
"default": default_gain_dB,
"units": "dB",
},
{
"name": "Second band cutoff",
"min": 800.0,
"max": 4000.0,
"default": 1000.0,
"units": "Hz",
},
{
"name": "Second band Q",
"min": min_q_factor,
"max": max_q_factor,
"default": default_q_factor,
"units": "",
},
{
"name": "Third band gain",
"min": min_gain_dB,
"max": max_gain_dB,
"default": default_gain_dB,
"units": "dB",
},
{
"name": "Third band cutoff",
"min": 2000.0,
"max": 8000.0,
"default": 4000.0,
"units": "Hz",
},
{
"name": "Third band Q",
"min": min_q_factor,
"max": max_q_factor,
"default": default_q_factor,
"units": "",
},
{
"name": "Fourth band gain",
"min": min_gain_dB,
"max": max_gain_dB,
"default": default_gain_dB,
"units": "dB",
},
{
"name": "Fourth band cutoff",
"min": 4000.0,
"max": (24000 // 2) * 0.9,
"default": 8000.0,
"units": "Hz",
},
{
"name": "Fourth band Q",
"min": min_q_factor,
"max": max_q_factor,
"default": default_q_factor,
"units": "",
},
{
"name": "Highshelf gain",
"min": min_gain_dB,
"max": max_gain_dB,
"default": default_gain_dB,
"units": "dB",
},
{
"name": "Highshelf cutoff",
"min": 4000.0,
"max": (24000 // 2) * 0.9,
"default": 8000.0,
"units": "Hz",
},
{
"name": "Highshelf Q",
"min": min_q_factor,
"max": max_q_factor,
"default": default_q_factor,
"units": "",
},
]
self.num_control_params = len(self.ports)
self.process_fn = parametric_eq
def forward(self, x, p, sample_rate=24000, **kwargs):
"All processing in the forward is in numpy."
return self.run_series(x, p, sample_rate)