JFReuter's profile - activity

I have a node that among many other things, publishes images for debugging purposes. However, this does not work all the time, and some messages never get seen by other nodes.

The messages get published from a subscription callback, if that makes a difference.

Symptoms:

• The first message never gets published
• Other messages (PointCloud2) work fine
• Messages don't get published, even when callback is idle
• cv_bridge or manual message creation makes no difference
• No error messages at all

I have verified that the publish method does get called, and even stepped into it. There does not seem to be a problem there.

I am at a loss. What could be the problem?

Edit :

#include <ros/publisher.h>
#include <ros/subscriber.h>
#include <ros/node_handle.h>
#include <sensor_msgs/Image.h>
#include <cv_bridge/cv_bridge.h>
#include <opencv2/core/core.hpp>

std::map<std::string, ros::Publisher> mPublishers;
ros::Subscriber imgSub;

template <class msg_type>
ros::Publisher getPublisher(const std::string& topic)
{

  if (mPublishers.find(topic) == mPublishers.end())
  {
    std::ostringstream ostr;
    ostr << "/" << "dump" << "/" << topic;
    ros::NodeHandle mNh;
    mPublishers[topic] = mNh.advertise<msg_type> (ostr.str(), 0, true);
  }

  return mPublishers[topic];
}

void cb(const sensor_msgs::ImageConstPtr& image_msg)
{
  ros::Time time = image_msg->header.stamp;


  cv_bridge::CvImageConstPtr cvImage = cv_bridge::toCvShare(image_msg, "");
  const cv::Mat& image = cvImage->image;

  sensor_msgs::ImagePtr msg(new sensor_msgs::Image());

  int numBytes = image.step * image.rows;
  msg->data.resize(numBytes);
  for (int i = 0; i < numBytes; ++i)
  {
    msg->data[i] = image.data[i];
  }
  msg->encoding = "rgb8";
  msg->header.stamp = time;
  msg->header.frame_id = image_msg->header.frame_id;
  msg->height = image.rows;
  msg->width = image.cols;
  msg->step = image.step;

  ros::Publisher pub = getPublisher<sensor_msgs::Image>("cascade_faces");
  pub.publish(msg);
}


int main (int argc, char** argv)
{
    // Initialize ROS
  ros::init (argc, argv, "my_template_alignment");

  ros::NodeHandle nh;

  imgSub = nh.subscribe("/camera/rgb/image_rect_color", 1, cb);


  std::cout << "ready!" << std::endl;

    // Spin
  ros::spin ();

  return (0);
}

Hi mate,

Xlib: extension "GLX" missing on display ":0.0" is more linux related. Try:

sudo apt-get purge nvidia*
sudo apt-get install --reinstall xserver-xorg-video-intel  libgl1-mesa-glx libgl1-mesa-dri    server-xorg-core
sudo dpkg-reconfigure xserver-xorg
sudo update-alternatives --remove gl_conf /usr/lib/nvidia-current/ld.so.conf

(see https://theiszm.wordpress.com/2010/06/27/glx-missing-on-display/). Do not worry about removing ros packages. You can reinstall them afterwards.

Regards, Tobias

When I try to run rviz, I get the following output:

[reuter@fahrsim04:~]$ rosrun rviz rviz                                                                                                                                                                             (07-13 17:48)
Xlib:  extension "NV-GLX" missing on display ":0.0".
[ INFO] [1310572108.380121383]: Loading general config from [/fzi/ids/reuter/.rviz/config]
[ INFO] [1310572108.380396700]: Loading display config from [/fzi/ids/reuter/.rviz/display_config]
The program 'rviz' received an X Window System error.
This probably reflects a bug in the program.
The error was 'GLXUnsupportedPrivateRequest'.
  (Details: serial 21 error_code 177 request_code 155 minor_code 16)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)
[reuter@fahrsim04:~]$

...and the program doesn't run.

Notes:

I get the message Xlib: extension "NV-GLX" missing on display ":0.0". for every glx program I run. I have not been able to determine what is causing this, as this system is using an intel card with an intel driver. All the programs work fine, though, and glxinfo reports that direct rendering is enabled.

A google search about the error has not yielded a solution.

What can I do to get rviz to work?