读 wav 音频画 mel 频谱图（python）_cv2实现音频频谱图

代码功能：

1. 读取wav音频文件
2. 以10s为一个单位截取音频，只截取每个音频的前60s
3. 调用librosa音频处理函数对10s音频进行mel频谱操作
4. 调用Matplotlib图像处理函数进行频谱图的绘画

import numpy as np
import glob
import librosa
import librosa.display
import matplotlib.pyplot as plt
import cv2




path_dir = 'C:/Users/Chengguo/Desktop/声音_行为/wav/'
for path in glob.glob(path_dir+"*.wav"):
    # path = "C:/Users/Chengguo/Desktop/声音_行为/wav/尖叫.wav"
    # print(path)
    for i in range(50):
        y, sr = librosa.load(path,sr=None,offset=i*1.0, duration=1.0)#librosa.ex('trumpet'))#声音强度、声音采样频率
        # print(len(y),sr)
        # plt.figure(figsize=(16,6))
        # librosa.display.waveplot(y, sr=sr)
        # plt.title('Signal');
        # plt.xlabel('Time (samples)')
        # plt.ylabel('Amplitude')
        
        '''FFT变换'''
        # n_fft = 2048
        # ft = np.abs(librosa.stft(y[:n_fft], hop_length = n_fft+1))
        # plt.figure()
        # plt.plot(ft);
        # plt.title('Spectrum');
        # plt.xlabel('Frequency Bin');
        # plt.ylabel('Amplitude');
        
        '''stft频谱变换'''
        # spec = np.abs(librosa.stft(y, hop_length=512))
        # spec = librosa.amplitude_to_db(spec, ref=np.max)
        # plt.figure(figsize=(16,6))
        # librosa.display.specshow(spec, sr=sr, x_axis='time', y_axis='log');
        # plt.colorbar(format='%+2.0f dB');
        # plt.title('Spectrogram');
        
        '''Mel频谱变换'''
        mel_spect = librosa.feature.melspectrogram(y=y, sr=sr, n_fft=2048, hop_length=1024)
        mel_spect = librosa.power_to_db((mel_spect), ref=np.max)
        plt.figure(figsize=(16,8))
        # kernel = np.ones((3,3),np.uint8)  ,
        # mel_spect = cv2.morphologyEx(mel_spect, cv2.MORPH_OPEN, kernel)
        
        librosa.display.TimeFormatter(lag=True)
        mel_img=librosa.display.specshow(mel_spect, y_axis='mel', x_axis='s')#, fmax=8000
    
        plt.title(f'Mel-Spectrogram-{i*1}')
        plt.colorbar(mel_img,format='%+2.0f dB')
        plt.savefig(f"{path[:-4]}/Log-Mel-Spectrogram-{i*1}.png")
        plt.close()


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