Question

我正在尝试绘制.wav文件的频谱图。下面的代码表现方式的奇怪之处在于它适用于某些.wav文件而在其他文件上失败。我怀疑这是因为一些.wav文件与其他文件相比具有不同数量的通道。但是我不知道如何确定.wav文件包含多少个通道。在发布我的问题之前，我已经查看了这个堆栈溢出帖子：What is a channel in a .wav file format?Do all channels play simultaneaously when a wav file is played?

我已粘贴下面的一个方法，尝试将文件路径（myAudio）转换为带有filepath（fileNameToSaveTo）的jpg。

def individualWavToSpectrogram(myAudio, fileNameToSaveTo):
print(myAudio)
#Read file and get sampling freq [ usually 44100 Hz ]  and sound object
samplingFreq, mySound = wavfile.read(myAudio)

#Check if wave file is 16bit or 32 bit. 24bit is not supported
mySoundDataType = mySound.dtype

#We can convert our sound array to floating point values ranging from -1 to 1 as follows

mySound = mySound / (2.**15)

#Check sample points and sound channel for duel channel(5060, 2) or  (5060, ) for mono channel

mySoundShape = mySound.shape
samplePoints = float(mySound.shape[0])

#Get duration of sound file
signalDuration =  mySound.shape[0] / samplingFreq

#If two channels, then select only one channel
mySoundOneChannel = mySound[:,0]

#Plotting the tone

# We can represent sound by plotting the pressure values against time axis.
#Create an array of sample point in one dimension
timeArray = numpy.arange(0, samplePoints, 1)

#
timeArray = timeArray / samplingFreq

#Scale to milliSeconds
timeArray = timeArray * 1000

#Plot the tone
plt.plot(timeArray, mySoundOneChannel, color='Black')
#plt.xlabel('Time (ms)')
#plt.ylabel('Amplitude')
print("trying to save")
plt.savefig('/Users/billybobjoe/Desktop/SavedSpecs' + fileNameToSaveTo + '.jpg')
print("saved")
plt.show()

这会在我的某些.wav文件中产生以下错误第57行，在个别的WWTTpectrogram中 mySoundOneChannel = mySound [：，0] IndexError：数组

的索引太多

失败的代码行是

mySoundOneChannel = mySound[:,0]

如何查看.wav文件的通道数，以及如何相应地设置mySoundOneChannel？

Answer 1

据我所知，如果有多个频道，数据数组mySound将具有形状(nSamples, nChannels)。如果有一个频道，则mySound的形状为(nSamples,)。

此处，您的音频文件必须只有一个频道，因此您无法将其编入索引，就像它是2D数组一样。

因此，您应该能够替换

mySoundOneChannel = mySound[:,0]

类似

if len(mySound.shape) > 1:
    mySoundOneChannel = mySound[:,0]
else:
    mySoundOneChannel = mySound

要获得频道数量，您应该可以：

if len(mySound.shape) > 1:
    nChannels = mySound.shape[1]
else:
    nChannels = 1

IndexError：尝试绘制.wav文件的频谱图时，数组的索引太多

1 个答案: