使用 python 音频处理的音符检测

Posted 2023-02-25

【中文标题】使用 python 音频处理的音符检测

【英文标题】：Music note detection using python audio processing

【发布时间】：2018-11-14 11:25:34

【问题描述】：

我给我的代码提供了一些没有提供适当输出的音频文件。 代码：

import numpy as np
import math
import wave
import os
import struct

def note_detect(audio_file):

    Detected_Note = ""

    beta = 1   
    max_notes = 100   
    sampling_freq = 38050 
    window_size = (sampling_freq / 37)   
    threshold = 600
    array = [440.00, 130.8, 329.6, 196]

    notes = ['A4', 'C3', 'E4', 'G3' ]
    Identified_Notes = []
    file_length = audio_file.getnframes()
    sound = np.zeros(file_length)
    for i in range(file_length):
        data = audio_file.readframes(1)
        data = struct.unpack("<h", data)
        sound[i] = int(data[0])
    sound = np.divide(sound, float(2**15))

    sound_square = np.square(sound)
    frequency = []
    dft = []
    i = 0
    j = 0
    k = 0
    while(i<=len(sound_square)-window_size):
        s = 0.0
        j = 0
        while(j<=window_size):
            s = s + sound_square[i+j]
            j = j + 1
        if s < threshold:
            if(i-k>window_size*4):
                dft = np.array(dft)
                dft = np.fft(sound[k:i])

                dft=np.argsort(dft)

                if(dft[0]>dft[-1] and dft[1]>dft[-1]):
                    i_max = dft[-1]
                elif(dft[1]>dft[0] and dft[-1]>dft[0]):
                    i_max = dft[0]
                else :
                    i_max = dft[1]

                frequency.append((i_max*sampling_freq)/(i-k))
                dft = []
                k = i+1
        i = i + window_size

    print('length',len(frequency))
    print("frequency")

    for i in frequency :
        print(i)
        idx = (np.abs(array-i)).argmin()
        Identified_Notes.append(notes[idx])
    print(Identified_Notes)
    Detected_Note=max(Identified_Notes,key=Identified_Notes.count)      
    return Detected_Note



if __name__ == "__main__":


    path = os.getcwd()

    file_name = path + "\Task_1.1_Audio_files\Audio_4.wav"
    audio_file = wave.open(file_name)

    Detected_Note = note_detect(audio_file)

    print("\n\tDetected Note = " + str(Detected_Note))


    x = raw_input("\n\tWant to check output for all Audio Files - Y/N: ")

    if x == 'Y':

        Detected_Note_list = []

        file_count = len(os.listdir(path + "\Task_1.1_Audio_files"))

        for file_number in range(1, file_count):

            file_name = path + "\Task_1.1_Audio_files\Audio_"+str(file_number)+".wav"
            audio_file = wave.open(file_name)

            Detected_Note = note_detect(audio_file)

            Detected_Note_list.append(Detected_Note)

        print("\n\tDetected Notes = " + str(Detected_Note_list))

音频文件链接： https://drive.google.com/open?id=1KVEQQUqBvwgDPf2JC_uQ0L6M_gzGDG6l

Audio_6.wav 的相应输出为 A4，Audio_4.wav 为 E4，Audio_5.wav 为 G3

【问题讨论】：

嗨，欢迎来到 SO。请查看Help centre。特别是，请在帖子中包含代码并解释您的问题。什么是“适当的输出”？它和你得到的有什么不同？没有人知道，除了你。

欢迎来到 SO ;) 请在 how to ask a good question 阅读这篇文章。这将包括对您要实现的目标的正确描述、您的代码（或相关的 sn-ps）以及显示您迄今为止尝试过的内容和可能的错误消息的努力。

我已经按照你的建议上传了代码。

【参考方案1】：

这可能是因为您使用的是自定义矩形窗口，请尝试使用 scipy.signal 中的 blackmanharris 并使用 np.argmax 来计算 i_max。 我检查了音频文件，它们只有 1 个频率，但您从算法中计算出 4 个频率，然后取最高频率。 我已经调整了代码看一下，但Audio_4.wav文件仍然显示我这边的注释E5，这可能是你给的注释可能是错误的，你能检查一下吗？

def matching_freq(freq):
    note=""
    if(freq>15 and freq<17.32):
        note= "C0"
        return note
    elif(freq>17.32 and freq<19.45):
        note="D0"
        return note
    elif(freq>19.45 and freq<20.8):
        note="E0"
        return note
    elif(freq>20.8 and freq<23.12):
        note="F0"
        return note
    elif(freq>23.12 and freq<25.96):
        note="G0"
        return note
    elif(freq>25.96 and freq<29.14):
        note="A0"
        return note
    elif(freq>29.14 and freq<31):
        note="B0"
        return note
    elif(freq>31 and freq<34.65):
        note="C1"
        return note
    elif(freq>34.65 and freq<38.89):
        note="D1"
        return note
    elif(freq>38.89 and freq<42):
        note="E1"
        return note
    elif(freq>42 and freq<46.25):
        note="F1"
        return note
    elif(freq>46.25 and freq<51.91):
        note="G1"
        return note
    elif(freq>51.91 and freq<58.27):
        note="A1"
        return note
    elif(freq>58.27 and freq<63):
        note="B1"
        return note
    elif(freq>63 and freq<69.30):
        note="C2"
        return note
    elif(freq>69.30 and freq<77.78):
        note="D2"
        return note
    elif(freq>77.78 and freq<85):
        note="E2"
        return note
    elif(freq>85 and freq<92.50):
        note="F2"
        return note
    elif(freq>92.50 and freq<103.83):
        note="G2"
        return note
    elif(freq>103.83 and freq<116.54):
        note="A2"
        return note
    elif(freq>116.54 and freq<126):
        note="B2"
        return note
    elif(freq>126 and freq<138.59):
        note="C3"
        return note
    elif(freq>138.59 and freq<155.56):
        note="D3"
        return note
    elif(freq>155.56 and freq<168):
        note="E3"
        return note
    elif(freq>168 and freq<185):
        note="F3"
        return note
    elif(freq>185 and freq<207.65):
        note="G3"
        return note
    elif(freq>207.65 and freq<233.08):
        note="A3"
        return note
    elif(freq>233.08 and freq<253):
        note="B3"
        return note
    elif(freq>253 and freq<277.18):
        note="C4"
        return note
    elif(freq>277.18 and freq<311.13):
        note="D4"
        return note
    elif(freq>311.13 and freq<338):
        note="E4"
        return note
    elif(freq>338 and freq<369.99):
        note="F4"
        return note
    elif(freq>369.99 and freq<415.3):
        note="G4"
        return note
    elif(freq>415.3 and freq<466.16):
        note="A4"
        return note
    elif(freq>466.16 and freq<500):
        note="B4"
        return note
    elif(freq>500 and freq<554.37):
        note="C5"
        return note
    elif(freq>554.37 and freq<622.25):
        note="D5"
        return note
    elif(freq>622.25 and freq<675):
        note="E5"
        return note
    elif(freq>675 and freq<740):
        note="F5"
        return note
    elif(freq>740 and freq<830):
        note="G5"
        return note
    elif(freq>830 and freq<932):
        note="A5"
        return note
    elif(freq>932 and freq<1000):
        note="B5"
        return note
    elif(freq>1000 and freq<1108):
        note="C6"
        return note
    elif(freq>1108 and freq<1244):
        note="D6"
        return note
    elif(freq>1244 and freq<1350):
        note="E6"
        return note
    elif(freq>1350 and freq<1480):
        note="F6"
        return note
    elif(freq>1480 and freq<1661.22):
        note="G6"
        return note
    elif(freq>1661.22 and freq<1864):
        note="A6"
        return note
    elif(freq>1864 and freq<2000):
        note="B6"
        return note
    elif(freq>2000 and freq<2217.46):
        note="C7"
        return note
    elif(freq>2217.46 and freq<2489.02):
        note="D7"
        return note
    elif(freq>2489.02 and freq<2700):
        note="E7"
        return note
    elif(freq>2700 and freq<2960):
        note="F7"
        return note
    elif(freq>2960 and freq<3322.4):
        note="G7"
        return note
    elif(freq>3322.4 and freq<3729):
        note="A7"
        return note
    elif(freq>3729.31 and freq<4040):
        note="B7"
        return note
    elif(freq>4040 and freq<4435):
        note="C8"
        return note
    elif(freq>4435 and freq<4978):
        note="D8"
        return note
    elif(freq>4978 and freq<5350):
        note="E8"
        return note
    elif(freq>5350 and freq<5919):
        note="F8"
        return note
    elif(freq>5919 and freq<6644):
        note="G8"
        return note
    elif(freq>6644 and freq<7458):
        note="A8"
        return note
    elif(freq>7458 and freq<8000):
        note="B8"
        return note


def note_detect(audio_file):
Detected_Note = []
length = audio_file.getnframes()
sound  = np.zeros(length)

for i in range(length):
    data = audio_file.readframes(1)
    data = struct.unpack("<h", data)
    sound[i] = int(data[0])

sound = np.divide(sound, float(2**15))
window = sound * np.blackmanharris(len(sound))
f = np.fft.fft(window)
i_max = np.argmax(abs(f))
print(i_max)
freq = (i_max * fs)/len(sound)
print(freq)
Detected_Note = matching_freq(freq)
return Detected_Note`

【讨论】：

我已经检查了所有的音频文件，它们给出了我的查询中给出的适当输出。我已经浏览了您的代码，并在名为 Audio_2.wav 的驱动器中添加了一个音频文件，其中包含注释 A4，通过您的代码，我得到了 E7。