rosbag record 报错：rosbag record buffer exceeded. Dropping oldest queued message.

问题描述： 

 针对上面的问题解决的方法有：

方法1：换个读写速度更快的SSD硬盘

--------------------------亲测可用---------------------------

方法2：压缩原始图像大小

安装插件

sudo apt-get install ros-melodic-image-transport-plugins

创建catkin_ws工作空间下的功能包，名字    image_compressor

launch/start_compressor.launch

start_compressor.launch

<launch>
  <node name="image_compressor_node" pkg="image_compressor" type="image_compressor_node" output="screen"/>
</launch>

src/image_compressor_node.cpp

image_compressor_node.cpp

#include <ros/ros.h>
#include <opencv2/highgui/highgui.hpp>
#include <cv_bridge/cv_bridge.h>
#include <sensor_msgs/CompressedImage.h>
#include <opencv2/imgcodecs.hpp>
 
class ImageCompressorNode
{
public:
  ImageCompressorNode()
  {
    // 订阅压缩图像话题
    for (const auto& topic : compressed_input_topics_)
    {
      subscribers_.push_back(nh_.subscribe<sensor_msgs::CompressedImage>(topic, 1, &ImageCompressorNode::compressedImageCallback, this));
    }
    
    // 发布压缩后的图像话题
    for (const auto& topic : compressed_output_topics_)
    {
      compressed_publishers_.push_back(nh_.advertise<sensor_msgs::CompressedImage>(topic, 1));
    }
  }
 
private:
  void compressedImageCallback(const sensor_msgs::CompressedImageConstPtr& msg)
  {
    try
    {
      cv::Mat image = cv::imdecode(cv::Mat(msg->data), cv::IMREAD_COLOR);
      if(image.empty()) {
        ROS_ERROR("Failed to decode image");
        return;
      }
 
      std::vector<uchar> buffer;
      std::vector<int> compression_params;
      compression_params.push_back(cv::IMWRITE_JPEG_QUALITY);
      compression_params.push_back(95); // Quality from 0 to 100
 
      cv::imencode(".jpg", image, buffer, compression_params);
 
      sensor_msgs::CompressedImage compressed_msg;
      compressed_msg.header = msg->header;
      compressed_msg.format = "jpeg";
      compressed_msg.data = buffer;
 
      // 发布压缩后的图像
      std::string topic = msg->header.frame_id;
      auto it = std::find(compressed_input_topics_.begin(), compressed_input_topics_.end(), topic);
      if (it != compressed_input_topics_.end())
      {
        size_t index = std::distance(compressed_input_topics_.begin(), it);
        compressed_publishers_[index].publish(compressed_msg);
      }
    }
    catch (cv_bridge::Exception& e)
    {
      ROS_ERROR("Could not convert to image: %s", e.what());
    }
  }
 
  ros::NodeHandle nh_;
  std::vector<std::string> compressed_input_topics_ = {
    "/usb_cam1/image_raw/compressed",
    "/usb_cam2/image_raw/compressed",
    "/usb_cam3/image_raw/compressed",
    "/usb_cam4/image_raw/compressed",
    "/usb_cam5/image_raw/compressed"
  };
  std::vector<std::string> compressed_output_topics_ = {
    "/usb_cam1/image_compressed",
    "/usb_cam2/image_compressed",
    "/usb_cam3/image_compressed",
    "/usb_cam4/image_compressed",
    "/usb_cam5/image_compressed"
  };
  std::vector<ros::Subscriber> subscribers_;
  std::vector<ros::Publisher> compressed_publishers_;
};
 
int main(int argc, char **argv)
{
  ros::init(argc, argv, "image_compressor_node");
  ImageCompressorNode node;
  ros::spin();
  return 0;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.0.2)
project(image_compressor)
 
find_package(catkin REQUIRED COMPONENTS
  roscpp
  sensor_msgs
  cv_bridge
  image_transport
)
 
find_package(OpenCV REQUIRED)
 
catkin_package(
  CATKIN_DEPENDS roscpp sensor_msgs cv_bridge image_transport
)
 
include_directories(
  ${catkin_INCLUDE_DIRS}
  ${OpenCV_INCLUDE_DIRS}
)
 
add_executable(${PROJECT_NAME}_node src/image_compressor_node.cpp)
 
target_link_libraries(${PROJECT_NAME}_node
  ${catkin_LIBRARIES}
  ${OpenCV_LIBRARIES}
)

package.xml

<?xml version="1.0"?>
<package format="2">
  <name>image_compressor</name>
  <version>0.0.0</version>
  <description>The image_compressor package</description>
 
  <maintainer email="user@todo.todo">user</maintainer>
  <license>TODO</license>
 
  <buildtool_depend>catkin</buildtool_depend>
 
  <build_depend>roscpp</build_depend>
  <build_depend>sensor_msgs</build_depend>
  <build_depend>cv_bridge</build_depend>
  <build_depend>image_transport</build_depend>
 
  <exec_depend>roscpp</exec_depend>
  <exec_depend>sensor_msgs</exec_depend>
  <exec_depend>cv_bridge</exec_depend>
  <exec_depend>image_transport</exec_depend>
 
</package>

cd ~catkin_ws
catkin_make
 
source devel/setup.bash 
roslaunch multi_cam multi_cam.launch 
roslaunch image_compressor start_compressor.launch

查看话题如下：

录用包的时候将

rosbag record /usb_cam1/image_raw /usb_cam2/image_raw /usb_cam3/image_raw /usb_cam4/image_raw  /usb_cam5/image_raw

换成

rosbag record /usb_cam1/image_raw/compressed /usb_cam2/image_raw/compressed /usb_cam3/image_raw/compressed /usb_cam4/image_raw/compressed /usb_cam5/image_raw/compressed

--------------------------亲测可用，但是画质有所损伤---------------------------

方法3： 提高rosbag的缓存空间

rosbag record -b 4096 /usb_cam1/image_raw /usb_cam2/image_raw /usb_cam3/image_raw /usb_cam4/image_raw /usb_cam5/image_raw

--------------------------此方法效果不太明显---------------------------