Teddy_NTU's profile - activity

In the rosbag/Code API, we could see the msg by:

 import rosbag
 bag = rosbag.Bag('test.bag')
 for topic, msg, t in bag.read_messages(topics=['chatter', 'numbers']):
     print msg
 bag.close()

When I try this, I see several msg entries. How could I select only one of entries to display?

Like, for example. How could I get the data vector only?

Thanks a lot, your code really helps me out.

SteadyTimer related types not found I was trying to install the ROS wrapper for Astra camera on a raspberry pi 3, howeve

Read a msg inside a bagfile In the rosbag/Code API, we could see the msg by: import rosbag bag = rosbag.Bag('test.bag

Currently I have a bag file which recorded a camera view topic. Now I want to extract the image date with its corresponding time stamp. I am able to get the png form of the image data using the official way provided by ROS wiki, but some frames are missing even if I change the sec_per_frame parameter to be lower than 0.03. I am wondering what is the proper way to extract the image data.

To get the Bag Time, I simply rosplay the bag file and copy the information comes out from the terminal manually. It is okay for short-time recording, but definitely not a possible way for a long-time one. Is there a way I can save the bag time stamp into a text file directly? Is it possible to get the extracted images along with its corresponding time stamp?

Regards.

How to extract images from a bagfile properly Currently I have a bag file which recorded a camera view topic. Now I want

Hello ROS Community

As is shown in the title, I have recorded some gps data using ublox device in a bag file, which can be seen by rostopic echo. However, I am wondering how can I be able to dispaly the gps data (probably on google map or somewhere else).

Regards.

Display the gps topic in a bag file Hello ROS Community As is shown in the title, I have recorded some gps data using u

pointgrey_camera_driver crashes when topics are subscribed Hi ROS Community, I have a pointgrey usb camera, and I try t

Hello ROS Community,

I am a beginner to ROS. I used the audio_capture package provided by ROS Wiki to capture the audio data from a usb-microphone and use rosbag record to record the audio topic into a bagfile. Using the audio_play package provided, I was able to hear the audio when I rosbag play the bagfile. Now I want to extract the audio data of the bagfile to a external mp3 or wav file, but I don't know how to.

I know that the audio_capture package does contain a capture_to_file.launch file to capture real-time audio into mp3 file, but I only want the historical audio data recorded by the bagfile.

Regards.

That works!!! Thanks!!!

Extract audio data from a bagfile into mp3 or wav format Hello ROS Community, I am a beginner to ROS. I used the audio_