Question

我正在尝试使用pynput来获取实时键盘输入，但是on_press函数会在自动重复时被调用。

示例代码：

#!/usr/bin/env python3

import sys

import numpy as np
import sounddevice as sd

from pynput import keyboard

frequency = []

def on_press(key):
    global frequency
    try:
        print(key.vk)
        if key.char == "q":
            frequency.append(440)
        elif key.char == "w":
            frequency.append(880)
    except AttributeError:
        pass

def on_release(key):
    global frequency
    if key == keyboard.Key.esc:
        # Stop listener
        print("Press Enter")
        return False
    elif key.char == "q":
        frequency.remove(440)
    elif key.char == "w":
        frequency.remove(880)

listener = keyboard.Listener(
    on_press=on_press,
    on_release=on_release,
    suppress = True)
listener.start()

start_idx = 0

def callback(outdata, frames, time, status):
    if status:
        print(status, file=sys.stderr)
    print(frames)
    global start_idx
    t = (start_idx + np.arange(frames)) / 48000
    t = t.reshape(-1, 1)
    outdata[:] = 0 * t
    if len(frequency) > 0:
        print("Playing")
    for freq in frequency:
        outdata[:] = outdata[:] + 0.2 * np.sin(2 * np.pi * freq * t)

    start_idx += frames

try:
    with sd.OutputStream(channels=1, callback=callback,
            samplerate=48000):
        input()
        listener.stop()
except Exception as e:
    print("Exception")
    listener.stop()
    exit()

如果运行代码并按住Q键，键盘自动重复功能将启动并破坏整个侦听器。是否有python输入模块可以正确处理原始键盘输入？

第二件事是代码倾向于使我的Xorg经常崩溃。我只运行了几次脚本，Xorg崩溃了。我不知道为什么。 Linux 5.5.2-zen1-1-zen x86_64 GNU/Linux，X.Org 1.20.7。

第三件事是声音的合成似乎滞后了很多。回调函数的帧数似乎徘徊在400左右，以每秒48000个样本的速度小于10毫秒，但是实际的音频反馈感觉像是数百毫秒的延迟。

Answer 1

pygame具有很好的键侦听器，易于构建显示输出的GUI窗口。在Linux中也可以正常使用：

import pygame

def main_loop():
    #code
    loopExit = False
    while not loopExit:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                loopExit = True
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_q:
                    #code

            if event.type == pygame.KEYUP:
                if event.key == pygame.K_q:
                    #code

https://www.pygame.org/docs/ref/key.html

Pynput键盘侦听器自动重复

1 个答案: