musicpom/utils/fft_analyzer.py.ai
2025-04-02 20:48:07 -04:00

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# Credit
# https://github.com/ravenkls/MilkPlayer/blob/master/audio/fft_analyser.py
import time
from PyQt5 import QtCore
from pydub import AudioSegment
import numpy as np
from scipy.ndimage.filters import gaussian_filter1d
from logging import debug, info
class FFTAnalyser(QtCore.QThread):
"""Analyses a song using FFTs."""
calculatedVisual = QtCore.pyqtSignal(np.ndarray)
calculatedVisualRs = QtCore.pyqtSignal(np.ndarray)
def __init__(self, player, x_resolution): # noqa: F821
super().__init__()
self.player = player
self.reset_media()
self.player.currentMediaChanged.connect(self.reset_media)
self.resolution = x_resolution
# this length is a number, in seconds, of how much audio is sampled to determine the frequencies
# of the audio at a specific point in time
# in this case, it takes 5% of the samples at some point in time
self.sampling_window_length = 0.05
self.visual_delta_threshold = 1000
self.sensitivity = 0.2
def reset_media(self):
"""Resets the media to the currently playing song."""
audio_file = self.player.currentMedia().canonicalUrl().path()
# if os.name == "nt" and audio_file.startswith("/"):
# audio_file = audio_file[1:]
if audio_file:
try:
self.song = AudioSegment.from_file(audio_file).set_channels(1)
except PermissionError:
self.start_animate = False
else:
self.samples = np.array(self.song.get_array_of_samples())
self.max_sample = self.samples.max()
self.points = np.zeros(self.resolution)
self.start_animate = True
else:
self.start_animate = False
def calculate_amps(self):
"""Calculates the amplitudes used for visualising the media."""
sample_count = int(self.song.frame_rate * self.sampling_window_length)
start_index = int((self.player.position() / 1000) * self.song.frame_rate)
# samples to analyse
v_sample = self.samples[start_index : start_index + sample_count]
# Use a window function to reduce spectral leakage
window = np.hanning(len(v_sample))
v_sample = v_sample * window
# use FFTs to analyse frequency and amplitudes
fourier = np.fft.fft(v_sample)
freq = np.fft.fftfreq(fourier.size, d=1/self.song.frame_rate)
amps = np.abs(fourier)[:len(fourier)//2] # Only take positive frequencies
freq = freq[:len(fourier)//2] # Match frequencies to amplitudes
# Define frequency bands (in Hz)
bands = np.logspace(np.log10(10), np.log10(23000), self.resolution + 1)
point_samples = np.zeros(self.resolution)
# Calculate average amplitude for each frequency band
for i in range(len(bands) - 1):
mask = (freq >= bands[i]) & (freq < bands[i+1])
if np.any(mask):
point_samples[i] = np.mean(amps[mask])
# Calculate RMS of the sample for dynamic sensitivity
rms = np.sqrt(np.mean(np.square(v_sample)))
rms_ratio = min(0.2, rms / (0.01 * self.max_sample)) # Smooth transition near silence
# Normalize and apply sensitivity with RMS-based scaling
if np.max(point_samples) > 0:
point_samples = point_samples / np.max(point_samples)
point_samples = point_samples * self.sensitivity * rms_ratio
else:
point_samples = np.zeros(self.resolution)
# Update visualization points with decay
for n in range(self.resolution):
amp = point_samples[n]
if self.player.state() in (self.player.PausedState, self.player.StoppedState):
self.points[n] *= 0.95 # Fast decay when paused/stopped
elif amp < self.points[n]:
# More aggressive decay for very quiet signals
decay_factor = 0.7 if rms_ratio < 0.1 else 0.9
self.points[n] = max(amp, self.points[n] * decay_factor)
else:
self.points[n] = amp
# Apply Gaussian smoothing
rs = gaussian_filter1d(self.points, sigma=1)
# Emit the smoothed data
self.calculatedVisual.emit(rs)
def run(self):
"""Runs the animate function depending on the song."""
while True:
if self.start_animate:
try:
self.calculate_amps()
except ValueError:
self.calculatedVisual.emit(np.zeros(self.resolution))
self.start_animate = False
time.sleep(0.033)