I am a newer to ros, and I have a problem when try to save three different topics data to rosbag synchronously. I use the following code block to ensure the three different topics synchronously.

message_filters::Subscriber<sensor_msgs::PointCloud2> pointCloud_sub_; 
message_filters::Subscriber<sensor_msgs::Image> left_image_sub_;
message_filters::Subscriber<sensor_msgs::Image> right_image_sub_;
typedef message_filters::sync_policies::ApproximateTime<sensor_msgs::PointCloud2, sensor_msgs::Image, 
sensor_msgs::Image> multiSyncPolicy;
typedef message_filters::Synchronizer<multiSyncPolicy> multiSync;
boost::shared_ptr<multiSync> multiSync_;

std::string bagPath = "/home/XXX/Desktop/rosbagData/test.bag";
bag_.open(bagPath, rosbag::bagmode::Write);
pointCloud_sub_.subscribe(pMTNH, "/lidar", 1);
left_image_sub_.subscribe(pMTNH, "/leftCamera/nodeletTalker/RawImg", 1);
right_image_sub_.subscribe(pMTNH, "/rightCamera/nodeletTalker/RawImg", 1);
multiSync_.reset(new multiSync(multiSyncPolicy(4), pointCloud_sub_, left_image_sub_, right_image_sub_));
multiSync_->registerCallback(&nodeletListener::multiTopicsCallback, this);

the callback function is here: void nodeletListener::multiTopicsCallback(const sensormsgs::PointCloud2ConstPtr &pointCloud, const sensormsgs::Image::ConstPtr &leftImage, const sensormsgs::Image::ConstPtr &rightImage) { NODELETINFOSTREAM("pointCloud--left image diff time is " << pointCloud->header.stamp.toSec() - leftImage->header.stamp.toSec()); NODELETINFO_STREAM("left--right image diff time is " << leftImage->header.stamp.toSec() - rightImage->header.stamp.toSec()); //rosbag all the topics string leftCamTopic = "/leftCamera/nodeletTalker/RawImg"; string rightCamTopic = "/rightCamera/nodeletTalker/RawImg"; string lidarTopic = "/lidar";

bag_.write(leftCamTopic, leftImage->header.stamp, leftImage);
bag_.write(rightCamTopic, rightImage->header.stamp, rightImage);
bag_.write(lidarTopic, pointCloud->header.stamp, pointCloud);

}

the question is: I save the data in myown PC, the test.bag file is saved correctly, and can be used. However, when I copy this test.bag file into the other PC , the test.bag file can not be used correctly. I don't know why, please give me a hand, thank you very much.