实时控制音频播放：基于PyAudio的无固定时长声音生成与停止

import time
from rtmidi.midiutil import open_midiinput
import numpy as np
import pyaudio

p = pyaudio.PyAudio()
# play = True  # 移除 play 标志位

volume = 0.5  # range [0.0, 1.0]
fs = 44100  # sampling rate, Hz, must be integer
# duration = 5.0  # in seconds, may be float #Duration已经不需要了
fA = 440.0  # sine frequency, Hz, may be float
fB = 493.88
fC = 523.25
fD = 587.33

frekvence = 440


frekvence_seznam = {
    (144, 32): fA,
    (144, 33): fB,
    (144, 34): fC,
    (144, 35): fD,


}

port = 0

midiin, port_name = open_midiinput(port)

stream = None #初始化stream

try:
    while True:
        msg = midiin.get_message()

        if msg:
            # klic = tuple(vstupni_list[:2])
            message = msg
            klic = message[0]
            lepsi_klic = tuple(klic[:2])
            print(message[0])

            if lepsi_klic in frekvence_seznam:
                print("je to tam")
                frekvence = frekvence_seznam[lepsi_klic]

                period = 2 * np.pi
                x = period * np.arange(fs * 0.1) * frekvence / fs #减小duration，避免卡顿

                sinus = np.sin(x)
                square = np.sign(sinus)
                triangle = 2/np.pi * np.arcsin(np.sin(x))
                saw = abs((x % period) - 1)
                curvy_triangle = (abs((x % period) - 1)) ** 2

                samples = (triangle).astype(np.float32)

                # for paFloat32 sample values must be in range [-1.0, 1.0]
                if stream is None or not stream.is_active(): #检查stream是否已经被初始化或关闭
                    stream = p.open(format=pyaudio.paFloat32,
                                    channels=1,
                                    rate=fs,
                                    output=True)

                vysledek = volume * samples

                # spusteni zvuku
                stream.write(vysledek) #移除while循环，持续播放

            elif lepsi_klic == (144, 81):
                exit()
            else: #按键抬起时停止播放
                if stream is not None and stream.is_active():
                    stream.stop_stream()
                    # stream.close() # stream close放到循环外
except KeyboardInterrupt:
    print("Exiting program")
finally:
    if stream is not None and stream.is_active():
        stream.stop_stream()
    if stream is not None:
        stream.close()
    p.terminate()