在Raspberry Pi Zero中使用Python Sounddevice播放音频，然后我需要重新启动一次

Question

我的灵感来自这个项目将PI放入旧的旋转电话中。我正在使用Python将其栩栩如生，并执行我想执行的功能。第一个非常简单：当我拿起接收器时，请播放拨号音。

但是，当我尝试使用SoundDevice模块播放音频时，它将第一次使用，然后停止工作。而且，当我说停止工作时，我再也无法使用aplay或说话者检验或其他任何内容播放音频，直到重新启动为止。它使我认为在播放结束时没有正确关闭的东西。

硬件设置：

• raspberry pi Zero wh
• usb usb音频适配器

下面是我的代码类，Dioltone，本来是由我的Core应用程序运行的线程，因此在必要时可以启动/停止拨号音。底部是main，旨在测试功能。它可以很好地工作，在窗户上一遍又一遍地，但是当我在pi上运行一次时，它只能使用一次。同时，我可以aplay一遍又一遍地没有问题（前提是我没有尝试使用Python播放它）。

难道它正在锁定某些资源而不是发布吗？在该过程退出后，它以某种方式保持活跃？我在哪里寻找？可能是什么？

class DialTone(Thread):

    def __init__(self, input_queue:Queue, device:int_or_str ) -> None:
        """Initialize the dialtone class 

        Args:
            input_queue (Queue): A way to communicate with the thread
        """
        super().__init__()
        global _DIAL_TONE_FILE

        self.input_queue = input_queue
        sd.default.device = device

        # Commit the dial-tone data to memory so we can start/end quickly
        try:
            self.data, self.fs = sf.read(_DIAL_TONE_FILE, always_2d=True)
        except Exception as e:
            logging.debug( type(e).__name__ + ":" + str(e) )
    
    def run(self) -> None:
        """Play a dial tone in a continuous loop until we die
        """
        while( True ):
            cmd = self.input_queue.get(True)
            if( cmd == DialToneComms.DT_START ):
                logging.debug("DT: starting dial tone")
                sd.play(self.data, self.fs, loop=True)
                logging.debug(sd.get_status())
            elif( cmd == DialToneComms.DT_END ):
                logging.debug("DT: stopping dial tone")
                try:
                    sd.stop(ignore_errors=False)
                except Exception as e:
                    logging.error( type(e).__name__ + ":" + str(e) )
                logging.debug(sd.get_status())
            elif( cmd == DialToneComms.DT_KILL ):
                logging.debug("DT: killing self")
                try:
                    sd.stop(ignore_errors=False)
                except Exception as e:
                    logging.error( type(e).__name__ + ":" + str(e) )
                logging.debug(sd.get_status())
                break

# Test this capability
if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("--device",type=int_or_str,help="Audio device to use", default=1)
    parser.add_argument("--play_time",type=float,help="how long to play the dial tone",default=10.0)
    parser.add_argument("--num_cycles", type=int, help="Number of play, wait cycles", default=2)
    args = parser.parse_args()

    # Setup logging
    logging.basicConfig(level=logging.DEBUG)

    dial_tone_queue = Queue()
    print( "Instantiating DialTone" )
    dial_tone = DialTone(dial_tone_queue, args.device)
    print( "Starting DialTone Thread" )
    dial_tone.start()

    # Play the dial tone a number of iterations
    for _ in range(args.num_cycles):
        print( "Playing dialtone for {} sec".format(args.play_time))
        dial_tone_queue.put(DialToneComms.DT_START)
        time.sleep(args.play_time)
        dial_tone_queue.put(DialToneComms.DT_END)
        
        print("Waiting 2 seconds")
        time.sleep(2)

    print("Kill the thread")
    dial_tone_queue.put(DialToneComms.DT_KILL)
    print("Joining DialTone")
    dial_tone.join(_JOIN_WAIT_TIME)

    if( dial_tone.is_alive() ):
        logging.warning( "Dial tone thread is still alive! What gives?" )
    else:
        logging.warning( "Dial tone thread is nice and dead")

在PI上进行第一次运行的输出。底部的错误是我停止了没有播放的流的结果（停止电话已经杀死了它，而杀戮电话肯定只是在确保）。

Instantiating DialTone
Starting DialTone Thread
Playing dialtone for 3.0 sec
DEBUG:root:DT: starting dial tone
DEBUG:root:
Waiting 2 seconds
DEBUG:root:DT: stopping dial tone
DEBUG:root:
Playing dialtone for 3.0 sec
DEBUG:root:DT: starting dial tone
DEBUG:root:
Waiting 2 seconds
DEBUG:root:DT: stopping dial tone
DEBUG:root:
Playing dialtone for 3.0 sec
DEBUG:root:DT: starting dial tone
DEBUG:root:
Waiting 2 seconds
DEBUG:root:DT: stopping dial tone
DEBUG:root:
Kill the thread
Joining DialTone
DEBUG:root:DT: killing self
ERROR:root:PortAudioError:Error stopping stream: Invalid stream pointer [PaErrorCode -9988]
DEBUG:root:
WARNING:root:Dial tone thread is nice and dead

PI上的第二次输出。请注意，事情开始发生在秩序中，尤其是在停止之后，但是音频从未第二次播放。

Instantiating DialTone
Starting DialTone Thread
Playing dialtone for 3.0 sec
DEBUG:root:DT: starting dial tone
DEBUG:root:
Waiting 2 seconds
DEBUG:root:DT: stopping dial tone
Playing dialtone for 3.0 sec
Waiting 2 seconds
Playing dialtone for 3.0 sec
Waiting 2 seconds
Kill the thread
Joining DialTone
DEBUG:root:
DEBUG:root:DT: starting dial tone
DEBUG:root:
DEBUG:root:DT: stopping dial tone
WARNING:root:Dial tone thread is still alive! What gives?
DEBUG:root:
DEBUG:root:DT: starting dial tone
DEBUG:root:
DEBUG:root:DT: stopping dial tone
DEBUG:root:
DEBUG:root:DT: killing self
ERROR:root:PortAudioError:Error stopping stream: Invalid stream pointer [PaErrorCode -9988]
DEBUG:root:

Windows上的输出：

Instantiating DialTone
Starting DialTone Thread
Playing dialtone for 3.0 sec
DEBUG:root:DT: starting dial tone
DEBUG:root:
Waiting 2 seconds
DEBUG:root:DT: stopping dial tone
DEBUG:root:
Playing dialtone for 3.0 sec
DEBUG:root:DT: starting dial tone
DEBUG:root:
DEBUG:root:DT: stopping dial tone
Waiting 2 seconds
DEBUG:root:
Playing dialtone for 3.0 sec
DEBUG:root:DT: starting dial tone
DEBUG:root:
Waiting 2 seconds
DEBUG:root:DT: stopping dial tone
DEBUG:root:
Kill the thread
DEBUG:root:DT: killing self
Joining DialTone
ERROR:root:PortAudioError:Error stopping stream: Invalid stream pointer [PaErrorCode -9988]
DEBUG:root:
WARNING:root:Dial tone thread is nice and dead