python - 在按键按下事件上多次调用 on_press 回调

Question

我试图在按下按钮时从我的麦克风录音，问题是我正在使用的库无法检测到暂停事件。它仅在按下时检测，这会发生一次，这意味着麦克风仅记录一个样本。

import pyaudio
import wave
from pynput import keyboard

CHUNK = 8192
FORMAT = pyaudio.paInt16
CHANNELS = 2
RATE = 44100
RECORD_SECONDS = 5
WAVE_OUTPUT_FILENAME = "output.wav"

p = pyaudio.PyAudio()
stream = p.open(format=FORMAT,
                channels=CHANNELS,
                rate=RATE,
                input=True,
                frames_per_buffer=CHUNK)         
frames = []

def on_press(key):
    if key == keyboard.Key.cmd_l:
        print('- Started recording -'.format(key))
        try:
            data = stream.read(CHUNK)
            frames.append(data)
        except IOError: 
            print 'warning: dropped frame' # can replace with 'pass' if no message desired 
    else:
        print('incorrect character {0}, press cmd_l'.format(key))


def on_release(key):
    print('{0} released'.format(
        key))
    if key == keyboard.Key.cmd_l:
        print('{0} stop'.format(key))
        keyboard.Listener.stop
        return False

print("* recording")


with keyboard.Listener(on_press=on_press, on_release=on_release) as listener:
    listener.join()

print("* done recording")

stream.stop_stream()
stream.close()
p.terminate()

wf = wave.open(WAVE_OUTPUT_FILENAME, 'wb')
wf.setnchannels(CHANNELS)
wf.setsampwidth(p.get_sample_size(FORMAT))
wf.setframerate(RATE)
wf.writeframes(b''.join(frames))
wf.close()

我正在使用 pynput用于键盘事件和 pyaudio 用于记录。它似乎记录了何时按下 cmd_l 并在我释放时停止。问题是生成的音频文件不包含任何内容，或者非常短，只有 0.19 秒。

我想这可能与流有关。read 必须被多次调用，并且按键只被记录一次，因此只记录了一个样本。

但如果是这种情况，我如何让它多次调用 stream.read，同时还检测它何时被释放？或者是否有支持键盘上的 on_hold 机制的库？

更新的线程方法:

from pynput import keyboard
import time
import pyaudio
import wave

CHUNK = 8192
FORMAT = pyaudio.paInt16
CHANNELS = 2
RATE = 44100
RECORD_SECONDS = 5
WAVE_OUTPUT_FILENAME = "output.wav"

p = pyaudio.PyAudio()
frames = []

def callback(in_data, frame_count, time_info, status):
    return (in_data, pyaudio.paContinue)

class MyListener(keyboard.Listener):
    def __init__(self):
        super(MyListener, self).__init__(self.on_press, self.on_release)
        self.key_pressed = None
        
        self.stream = p.open(format=FORMAT,
                             channels=CHANNELS,
                             rate=RATE,
                             input=True,
                             frames_per_buffer=CHUNK,
                             stream_callback = self.callback)
        print self.stream.is_active()
    
    def on_press(self, key):
        if key == keyboard.Key.cmd_l:
            self.key_pressed = True
    
    def on_release(self, key):
        if key == keyboard.Key.cmd_l:
            self.key_pressed = False

    def callback(self,in_data, frame_count, time_info, status):
        if self.key_pressed == True:
            return (in_data, pyaudio.paContinue)
        elif self.key_pressed == False:
            return (in_data, pyaudio.paComplete)
        else:
            return (in_data,pyaudio.paAbort)


listener = MyListener()
listener.start()
started = False

while True:
    time.sleep(0.1)
    if listener.key_pressed == True and started == False:
        started = True
        listener.stream.start_stream()
        print "start Stream"

    elif listener.key_pressed == False and started == True:
        print "Something coocked"
        listener.stream.stop_stream()
        listener.stream.close()
        p.terminate()

        wf = wave.open(WAVE_OUTPUT_FILENAME, 'wb')
        wf.setnchannels(CHANNELS)
        wf.setsampwidth(p.get_sample_size(FORMAT))
        wf.setframerate(RATE)
        wf.writeframes(b''.join(frames))
        wf.close()

        started = False

我尝试了一种不同的方法，引入了两个线程，一个监视键盘，另一个整理录音。但是此解决方案不断丢帧，因此实际上没有记录任何内容？..

怎么会呢？

Answer 1

你可以做类似 this answer 的事情在单独的线程上定期运行函数的地方。似乎是最简单的解决方案。