用python写一边录音一边播放一边显示FFT波形的三线程pyqt5程序

以下是一种可能的实现方式：

import pyaudio
import numpy as np
import sys
import threading
from PyQt5.QtWidgets import QApplication, QMainWindow, QWidget, QVBoxLayout
from PyQt5.QtGui import QPainter, QPen
from PyQt5.QtCore import Qt


class RecordThread(threading.Thread):
    def __init__(self):
        super().__init__()
        self.chunk_size = 1024  # 每次读取的音频数据块大小
        self.sample_rate = 44100  # 采样率
        self.pa = pyaudio.PyAudio()
        self.stream = self.pa.open(format=pyaudio.paInt16,
                                   channels=1,
                                   rate=self.sample_rate,
                                   input=True,
                                   frames_per_buffer=self.chunk_size)

    def run(self):
        while True:
            data = self.stream.read(self.chunk_size)
            data_array = np.frombuffer(data, dtype=np.int16)
            spectrum = np.abs(np.fft.fft(data_array))[:self.chunk_size // 2]
            spectrum /= np.max(spectrum)
            spectrum = spectrum[:256]
            spectrum_db = 20 * np.log10(spectrum)
            spectrum_db = np.clip(spectrum_db, -50, 0)
            spectrum_db += 50
            spectrum_db /= 50
            spectrum_db = spectrum_db[::-1]
            # 将处理好的数据传递给UI线程
            ui_thread.update_spectrum(spectrum_db)


class PlayThread(threading.Thread):
    def __init__(self):
        super().__init__()
        self.chunk_size = 1024  # 每次播放的音频数据块大小
        self.sample_rate = 44100  # 采样率
        self.pa = pyaudio.PyAudio()
        self.stream = self.pa.open(format=pyaudio.paInt16,
                                   channels=1,
                                   rate=self.sample_rate,
                                   output=True,
                                   frames_per_buffer=self.chunk_size)

    def run(self):
        while True:
            data = np.zeros(self.chunk_size, dtype=np.int16)
            self.stream.write(data)


class UiThread(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle('Real-time FFT')
        self.setGeometry(200, 200, 800, 600)
        self.widget = QWidget()
        self.setCentralWidget(self.widget)
        self.layout = QVBoxLayout()
        self.widget.setLayout(self.layout)
        self.spectrum = np.zeros(256)  # 初始化频谱数据
        self.setMinimumWidth(600)
        self.setMinimumHeight(400)

    def paintEvent(self, event):
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing)
        painter.setPen(QPen(Qt.blue, 2))
        width = self.width()
        height = self.height()
        bar_width = width / len(self.spectrum)
        for i, value in enumerate(self.spectrum):
            x = i * bar_width
            y = height * (1 - value)
            painter.drawLine(x, height, x, y)

    def update_spectrum(self, spectrum):
        self.spectrum = spectrum
        self.update()


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ui_thread = UiThread()
    record_thread = RecordThread()
    play_thread = PlayThread()
    ui_thread.show()
    record_thread.start()
    play_thread.start()
    sys.exit(app.exec_())

这个程序中有三个线程：

- RecordThread：负责实时录音并进行FFT变换，将处理好的频谱数据传递给UI线程。
- PlayThread：负责实时播放静音，以保持麦克风始终处于工作状态。
- UiThread：负责显示频谱数据，并在接收到RecordThread传递的数据时更新界面。

在主函数中，先创建一个Qt应用程序，然后创建UiThread、RecordThread和PlayThread三个线程，并启动它们。最后进入应用程序的事件循环，等待用户关闭程序。