problem with android_tutorial_image_transport

rosjava / android_core

Android libraries for rosjava

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problem with android_tutorial_image_transport #271

Closed hungbui-io closed 7 years ago

hungbui-io commented 7 years ago

Hey guys,

I'm playing with the android_tutorial_image_transport. I want to show the images from rosbag file on an android device by changing the topic name: image.setTopicName("/tango/camera/color_1/image_rect/compressed"); but it did not show anything. Why is that? Am I missing something? Any helps would be much appreciated!

adamantivm commented 7 years ago

@hungbv11 as far as I know it should work. Some ideas to orient debugging:

Perhaps the problem is that the app is not using the time topic from the bag?
Perhaps there is a networking issue between the nodes (try to set ROS_IP on the host with the bag before launching the bag reading process)

hungbui-io commented 7 years ago

@adamantivm Thanks a lot for your reply

For time synchronization, I set the /use_sim_time to true and play the bag file with --clock but the app still didn't show anything.
For the networking issue, I don't quite understand what you means. I did test the android_camera_tutorial and it worked fine without error. Here are the rqt_graph of the nodes

adamantivm commented 7 years ago

@hungbv11 I am sorry I can't tell what could be wrong with that information. One other suggestion that comes to mind is to try display the image from a live topic instead of a bag file to see if that makes any difference.

hungbui-io commented 7 years ago

I wrote a simple node publishing images from laptop webcam but the android app did not subscribe anything :(

jubeira commented 7 years ago

Hi @hungbv11, I'd start by adding more logs to see what's happening exactly. I would try to avoid simulated clock times at the beginning to discard sources of error (see https://github.com/rosjava/rosjava_core/issues/148).

Perhaps as you say this is not the problem, but just for a reference about networking: http://wiki.ros.org/ROS/Technical%20Overview. It is explained there that all the nodes should be able to resolve each other's address/ name, and setting the variable ROS_IP in the linux side fixes that in some cases.

hungbui-io commented 7 years ago

Hey @adamantivm, I fixed the bug. I forgot to add "export ROS_IP" to the .bashrc file. Here is the the solution for my problem Anyway, I really appreciate your help! Cheers