Python sounddevice在面向对象编程中防止回调对象过早回收的策略

import sounddevice
import time

class SamplerBox:
    def __init__(self):
        self.samples = {} # 假设这里存储了大量数据，但不是崩溃的直接原因

    def audio_callback(self, outdata, frame_count, time_info, status):
        print('Audio callback running...')

    def init(self):
        self.connect_audio_output()
        self.load_samples() # 加载大量数据
        time.sleep(20) # 保持程序运行一段时间

    def connect_audio_output(self):
        try:
            # 问题所在：sd 是一个局部变量
            sd = sounddevice.OutputStream(callback=self.audio_callback)
            sd.start()
            print('Opened audio device')
        except Exception as e:
            print(f'Invalid audio device: {e}')
            exit(1)

    def load_samples(self):
        # 模拟加载大量数据，例如创建128*128个Sound对象
        for midinote in range(128):
            for velocity in range(128):
                self.samples[midinote, velocity] = Sound()

class Sound:
    def __init__(self):
        pass

# 运行示例
sb = SamplerBox()
sb.init()

import sounddevice
import time

class SamplerBox:
    def __init__(self):
        self.samples = {}
        self.sd = None # 初始化为None，表示尚未连接音频设备

    def audio_callback(self, outdata, frame_count, time_info, status):
        # 在这里处理音频数据，例如从self.samples中获取
        # print('Audio callback running...')
        pass # 实际应用中会填充outdata

    def init(self):
        self.connect_audio_output()
        self.load_samples()
        print("Application initialized. Running for 20 seconds...")
        time.sleep(20)
        self.disconnect_audio_output() # 确保在程序结束时关闭流

    def connect_audio_output(self):
        try:
            # 修正：将OutputStream对象赋值给实例属性self.sd
            self.sd = sounddevice.OutputStream(callback=self.audio_callback)
            self.sd.start()
            print('Opened audio device successfully.')
        except Exception as e:
            print(f'Failed to open audio device: {e}')
            exit(1)

    def disconnect_audio_output(self):
        if self.sd is not None:
            self.sd.stop()
            self.sd.close()
            print('Audio device closed.')

    def load_samples(self):
        for midinote in range(128):
            for velocity in range(128):
                self.samples[midinote, velocity] = Sound()
        print(f'Loaded {len(self.samples)} samples.')

class Sound:
    def __init__(self):
        pass

# 运行修正后的示例
sb = SamplerBox()
sb.init()
print("Application finished.")