[英]How to plot a wav file
我剛剛用 scipy 讀取了一個 wav 文件,現在我想使用 matplotlib 繪制文件圖,在“y 比例”上我想查看振幅,在“x 比例”上我想查看幀數! 任何幫助我該怎么做? 謝謝!
from scipy.io.wavfile import read
import numpy as np
from numpy import*
import matplotlib.pyplot as plt
a=read("C:/Users/Martinez/Desktop/impulso.wav")
print a
您可以調用 wave lib 來讀取音頻文件。
要繪制波形,請使用 matplotlib 中的“plot”函數
import matplotlib.pyplot as plt
import numpy as np
import wave
import sys
spf = wave.open("wavfile.wav", "r")
# Extract Raw Audio from Wav File
signal = spf.readframes(-1)
signal = np.fromstring(signal, "Int16")
# If Stereo
if spf.getnchannels() == 2:
print("Just mono files")
sys.exit(0)
plt.figure(1)
plt.title("Signal Wave...")
plt.plot(signal)
plt.show()
你會有類似的東西:
要以秒為單位繪制 x 軸,您需要獲得幀速率並除以信號大小,您可以使用 numpy 中的 linspace 函數創建一個與音頻文件大小線性間隔的時間向量,最后您可以再次使用 plot像plt.plot(Time,signal)
import matplotlib.pyplot as plt
import numpy as np
import wave
import sys
spf = wave.open("Animal_cut.wav", "r")
# Extract Raw Audio from Wav File
signal = spf.readframes(-1)
signal = np.fromstring(signal, "Int16")
fs = spf.getframerate()
# If Stereo
if spf.getnchannels() == 2:
print("Just mono files")
sys.exit(0)
Time = np.linspace(0, len(signal) / fs, num=len(signal))
plt.figure(1)
plt.title("Signal Wave...")
plt.plot(Time, signal)
plt.show()
以秒為單位的新圖 x 軸:
或者,如果您想使用 SciPy,您還可以執行以下操作:
from scipy.io.wavfile import read
import matplotlib.pyplot as plt
# read audio samples
input_data = read("Sample.wav")
audio = input_data[1]
# plot the first 1024 samples
plt.plot(audio[0:1024])
# label the axes
plt.ylabel("Amplitude")
plt.xlabel("Time")
# set the title
plt.title("Sample Wav")
# display the plot
plt.show()
根據@ederwander 的回答,這是一個也可以處理立體聲輸入的版本
import matplotlib.pyplot as plt
import numpy as np
import wave
file = 'test.wav'
with wave.open(file,'r') as wav_file:
#Extract Raw Audio from Wav File
signal = wav_file.readframes(-1)
signal = np.fromstring(signal, 'Int16')
#Split the data into channels
channels = [[] for channel in range(wav_file.getnchannels())]
for index, datum in enumerate(signal):
channels[index%len(channels)].append(datum)
#Get time from indices
fs = wav_file.getframerate()
Time=np.linspace(0, len(signal)/len(channels)/fs, num=len(signal)/len(channels))
#Plot
plt.figure(1)
plt.title('Signal Wave...')
for channel in channels:
plt.plot(Time,channel)
plt.show()
只是一個觀察(我不能添加評論)。
您將收到以下消息:
棄用警告:不推薦使用數字樣式的類型代碼,將來會導致錯誤。
不要將 np.fromstring 與二進制文件一起使用。 而不是signal = np.fromstring(signal, 'Int16')
,最好使用signal = np.frombuffer(signal, dtype='int16')
。
這是繪制波形文件的波形和頻譜的代碼
import wave
import numpy as np
import matplotlib.pyplot as plt
signal_wave = wave.open('voice.wav', 'r')
sample_rate = 16000
sig = np.frombuffer(signal_wave.readframes(sample_rate), dtype=np.int16)
對於整個波形文件段
sig = sig[:]
對於波形文件的部分片段
sig = sig[25000:32000]
分離立體聲通道
left, right = data[0::2], data[1::2]
繪制波形 (plot_a) 和頻譜 (plot_b)
plt.figure(1)
plot_a = plt.subplot(211)
plot_a.plot(sig)
plot_a.set_xlabel('sample rate * time')
plot_a.set_ylabel('energy')
plot_b = plt.subplot(212)
plot_b.specgram(sig, NFFT=1024, Fs=sample_rate, noverlap=900)
plot_b.set_xlabel('Time')
plot_b.set_ylabel('Frequency')
plt.show()
這是一個處理單聲道/立體聲和 8 位/16 位 PCM 的版本。
import matplotlib.pyplot as plt
import numpy as np
import wave
file = 'test.wav'
wav_file = wave.open(file,'r')
#Extract Raw Audio from Wav File
signal = wav_file.readframes(-1)
if wav_file.getsampwidth() == 1:
signal = np.array(np.frombuffer(signal, dtype='UInt8')-128, dtype='Int8')
elif wav_file.getsampwidth() == 2:
signal = np.frombuffer(signal, dtype='Int16')
else:
raise RuntimeError("Unsupported sample width")
# http://schlameel.com/2017/06/09/interleaving-and-de-interleaving-data-with-python/
deinterleaved = [signal[idx::wav_file.getnchannels()] for idx in range(wav_file.getnchannels())]
#Get time from indices
fs = wav_file.getframerate()
Time=np.linspace(0, len(signal)/wav_file.getnchannels()/fs, num=len(signal)/wav_file.getnchannels())
#Plot
plt.figure(1)
plt.title('Signal Wave...')
for channel in deinterleaved:
plt.plot(Time,channel)
plt.show()
我想我可以把它放在評論中,但稍微建立在@ederwander 和 @TimSC 的答案的基礎上,我想做一些更精細(如詳細)和美觀的東西。 下面的代碼創建了我認為非常好的立體聲或單聲道波形文件的波形(我不需要標題,所以我只是將其注釋掉,也不需要 show 方法 - 只需要保存圖像文件) .
和代碼,與我提到的差異:
import matplotlib.pyplot as plt
import numpy as np
import wave
file = '/Path/to/my/audio/file/DeadMenTellNoTales.wav'
wav_file = wave.open(file,'r')
#Extract Raw Audio from Wav File
signal = wav_file.readframes(-1)
if wav_file.getsampwidth() == 1:
signal = np.array(np.frombuffer(signal, dtype='UInt8')-128, dtype='Int8')
elif wav_file.getsampwidth() == 2:
signal = np.frombuffer(signal, dtype='Int16')
else:
raise RuntimeError("Unsupported sample width")
# http://schlameel.com/2017/06/09/interleaving-and-de-interleaving-data-with-python/
deinterleaved = [signal[idx::wav_file.getnchannels()] for idx in range(wav_file.getnchannels())]
#Get time from indices
fs = wav_file.getframerate()
Time=np.linspace(0, len(signal)/wav_file.getnchannels()/fs, num=len(signal)/wav_file.getnchannels())
plt.figure(figsize=(50,3))
#Plot
plt.figure(1)
#don't care for title
#plt.title('Signal Wave...')
for channel in deinterleaved:
plt.plot(Time,channel, linewidth=.125)
#don't need to show, just save
#plt.show()
plt.savefig('/testing_folder/deadmentellnotales2d.png', dpi=72)
我想出了一個更靈活、更高效的解決方案:
import matplotlib.pyplot as plt
import numpy as np
import wave
import math
file = 'audiofile.wav'
with wave.open(file,'r') as wav_file:
num_channels = wav_file.getnchannels()
frame_rate = wav_file.getframerate()
downsample = math.ceil(frame_rate * num_channels / 2) # Get two samples per second!
process_chunk_size = 600000 - (600000 % frame_rate)
signal = None
waveform = np.array([])
while signal is None or signal.size > 0:
signal = np.frombuffer(wav_file.readframes(process_chunk_size), dtype='int16')
# Take mean of absolute values per 0.5 seconds
sub_waveform = np.nanmean(
np.pad(np.absolute(signal), (0, ((downsample - (signal.size % downsample)) % downsample)), mode='constant', constant_values=np.NaN).reshape(-1, downsample),
axis=1
)
waveform = np.concatenate((waveform, sub_waveform))
#Plot
plt.figure(1)
plt.title('Waveform')
plt.plot(waveform)
plt.show()
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