Question

我想使用pyaudio获得频率，并通过matplotlib将其绘制在图表中。因此，我使用pyaudio从音频输入中获取数据，效果很好，但我不知道如何从原始信号中获取频率。我找到了这个piece of code，它应该可以完成工作，但是我不知道如何将其应用于我的代码。

在这里设置麦克风并准备录音：

# constants
CHUNK = 1024 * 2             # samples per frame
FORMAT = pyaudio.paInt16     # audio format (bytes per sample?)
CHANNELS = 1                 # single channel for microphone
RATE = 44100                 # samples per second

# pyaudio class instance
mic = pyaudio.PyAudio()

# stream object to get data from microphone
stream = mic.open(
    format=FORMAT,
    channels=CHANNELS,
    rate=RATE,
    input=True,
    frames_per_buffer=CHUNK
)

这是我的代码部分，我从麦克风中获取数据：

data = stream.read(CHUNK)  

    # convert data to integers, make np array, then offset it by 127
    data_int = struct.unpack(str(2 * CHUNK) + 'B', data)

    # create np array and offset by 128
    data_np = np.array(data_int, dtype='b')[::2]
    data_np = [i+127 for i in data_np]

我只是将其放入while循环中，然后将其绘制在生命线图中。这是完整的代码：

import pyaudio      #for capturing the audio-signal
import struct       #for converting the binary-data from the signal to integer
import matplotlib.pyplot as plt     #for displaying the audio-signal

import numpy as np

#functions
def plot_setup():
    # create matplotlib figure and axes
    fig=plt.figure()
    ax=fig.add_subplot(111)

    # variable for plotting
    x = np.arange(0, 2 * CHUNK, 2)

    # create a line object with random data
    line, = ax.plot(x, [128 for i in range(2048)], '-')

    # basic formatting for the axes
    ax.set_title('AUDIO WAVEFORM')
    ax.set_xlabel('samples')
    ax.set_ylabel('volume')
    ax.set_ylim(0, 255)
    ax.set_xlim(0, 2 * CHUNK)
    plt.xticks([0, CHUNK, 2 * CHUNK])
    plt.yticks([0, 128, 255])
    # show the plot
    plt.show(block=False)
    return fig, line

def measure():
    # binary data
    data = stream.read(CHUNK)  

    # convert data to integers, make np array, then offset it by 127
    data_int = struct.unpack(str(2 * CHUNK) + 'B', data)

    # create np array and offset by 128
    data_np = np.array(data_int, dtype='b')[::2]
    data_np = [i+127 for i in data_np]

    line.set_ydata(data_np)
    try:
        fig.canvas.draw()
        fig.canvas.flush_events()
    except:
        return 0

# constants
CHUNK = 1024 * 2             # samples per frame
FORMAT = pyaudio.paInt16     # audio format (bytes per sample?)
CHANNELS = 1                 # single channel for microphone
RATE = 44100                 # samples per second

# pyaudio class instance
mic = pyaudio.PyAudio()

# stream object to get data from microphone
stream = mic.open(
    format=FORMAT,
    channels=CHANNELS,
    rate=RATE,
    input=True,
    frames_per_buffer=CHUNK
)

if __name__=="__main__":
    fig, line=plot_setup()
    while True:
        m=measure()
        if m==0:
            break

这是我得到的输出：最终的图应该看起来完全一样，只是我希望频率在y轴上。

如何获取音频信号python的频率

0 个答案: