我正在尝试创建一个UI界面，以同时播放ROS bag文件中的所有视频。为此，我使用了线程概念，就像每个视频的每个线程一样。

我可以播放所有视频，但是在播放时会出现以下错误，导致播放停止。

class Main(QMainWindow):

...

...

class videoThread(QtCore.QThread):

    def __init__(self,topic,bag,label):
        super().__init__()
        self.bag = bag
        self.topic = topic
        self.label = label
    def run(self):
        bridge = CvBridge()


       for topic,msg,t in self.bag.read_messages(topics=[self.topic]):
            img_dcam = bridge.compressed_imgmsg_to_cv2(msg,desired_encoding="passthrough")

            rgbImage = cv2.cvtColor(img_dcam,cv2.COLOR_BGR2RGB)

            convertToQtFormat = QImage(rgbImage.data,rgbImage.shape[1],rgbImage.shape[0],QImage.Format_RGB888)
            convertToQtFormat = QPixmap.fromImage(convertToQtFormat)
            pixmap = QPixmap(convertToQtFormat)
            resizeImage = pixmap.scaled(300,300,Qt.KeepAspectRatio)
            self.label.setPixmap(resizeImage)
            time.sleep(0.033)

def playVideo(self,topic):

    self.x = self.videoThread(topic,self.bag,self.label)
    self.x.start()

Traceback (most recent call last):
  File "rosmanager_main.py",line 1276,in run
    for topic,t in self.bag.read_messages(topics=[self.topic]):
  File "/opt/ros/melodic/lib/python2.7/dist-packages/rosbag/bag.py",line 2679,in read_messages
    yield self.seek_and_read_message_data_record((entry.chunk_pos,entry.offset),raw,return_connection_header)
  File "/opt/ros/melodic/lib/python2.7/dist-packages/rosbag/bag.py",line 2826,in seek_and_read_message_data_record
    header = _read_header(f)
  File "/opt/ros/melodic/lib/python2.7/dist-packages/rosbag/bag.py",line 1999,in _read_header
    raise ROSBagFormatException('Error reading header: %s' % str(ex))
rosbag.bag.ROSBagFormatException: Error reading header: expecting 606348583 bytes,read 871518