python - 如何同步python线程的开始时间？

Question

我想测量信号的时间延迟。为此，将信号放置在扬声器上，然后估计麦克风捕获信号的延迟。延迟预计在毫秒范围内，因此至关重要的是要同时启动扬声器信号和测量。
我的问题是，是否可以通过使用线程来实现:

def play_sound():
    # play sound

def record():
    # start recording


if __name__ == '__main__':
    t1 = threading.Thread(target=play_sound())
    t2 = threading.Thread(target=record())

    t1.start()
    t2.start()

还是有更好的方法？

Answer 1

我将首先启动记录线程，并在麦克风捕获的信号中寻找第一个峰值。这将告诉您在录制开始后多少毫秒内检测到第一个声音。为此，您可能需要知道mic etc-here的采样率是一个很好的起点。
时间线是这样的

---- recording start ------- playback start -------- sound first detected ----

You want to find out how many ms after you start recording a sound was picked up ((first_peak - recording_start) in the code below), and then subtract the time it took to start the playback ((playback_start - recording_start) below)

Here's a rough code outline

from datetime import datetime

recording_start, playback_start, first_peak = None, None, None

def play_sound():
    nonlocal playback_start
    playback_start = datetime.now()

def record():
    nonlocal recording_start, first_peak
    recording_start = datetime.now()
    first_peak = find_peak_location_in_ms()  # implement this


Thread(target=record()).start()  # note recording starts first
Thread(target=play_sound()).start()

# once the threads are finished
delay = (first_peak - recording_start) - (playback_start - recording_start)

PS其他答案之一正确指出您需要担心全局解释器锁定。您可以通过使用c级API来录制/播放声音而不会阻塞其他线程，从而绕过它，但是您可能会发现Python不适合该工作