音频干扰检测（时域方法）

holmes_sun52024-03-27 10:43

请注意注释掉的代码：逐个包络比对就不能加窗了。

import librosa

import numpy as np

from scipy.signal import windows

import matplotlib.pyplot as plt

读取音频文件

audio_file = 'sine.wav'

signal, sample_rate = librosa.load(audio_file, sr=None, mono=False)

检查通道数并处理信号

if signal.ndim > 1:

num_channels = signal.shape $0$

print(f"音频文件有 {num_channels} 个通道")

如果是4通道,取第X个通道进行处理，这里示例取第4个通道（索引为3）

if num_channels == 2:

signal = signal $0, :$

else:

如果信号是单通道，直接使用

print("音频文件是单通道")

计算每个周期的采样点数

cycle_samples = int(sample_rate / 1000)

# 创建汉宁窗

window_length = cycle_samples * 1 # 窗长度为10个周期

window = windows.hann(window_length)

# 对信号的开头和结尾分别应用汉宁窗

windowed_signal = signal.copy()

windowed_signal $:window_length//2$ *= window $:window_length//2$

windowed_signal $-window_length//2:$ *= window $window_length//2:$

计算周期数

num_cycles = len(signal) // cycle_samples

存储异常周期的时间点和幅值

anomaly_times = \[\]

anomaly_amplitudes = \[\]

逐个周期比较包络

for i in range(num_cycles - 1):

start = i * cycle_samples

end = (i + 1) * cycle_samples

current_cycle = signal $start:end$

next_cycle = signal $end:end+cycle_samples$

计算当前周期和下一个周期的包络差异

diff = np.abs(current_cycle - next_cycle)

如果差异大于阈值,则认为是异常周期

if np.max(diff) > 0.1:

anomaly_time = start / sample_rate

anomaly_times.append(anomaly_time)

anomaly_amplitudes.append(np.max(np.abs(current_cycle)))

打印异常周期的时间点和幅值

for time, amplitude in zip(anomaly_times, anomaly_amplitudes):

print(f"异常周期时间点: {time:.3f}s, 幅值: {amplitude:.3f}")

绘制时域波形图

time = np.arange(len(signal)) / sample_rate

plt.figure(figsize=(8,4))

plt.plot(time, signal, label='Signal')

标注异常周期

for t in anomaly_times:

plt.axvline(x=t, color='r', linestyle='--', label='Anomaly Detected')

plt.xlabel('Time(s)')

plt.ylabel('Amplitude')

plt.title('Windowed Waveform with Anomalies Highlighted')

plt.legend()

plt.show()