Charence's profile - activity

Sorry, I cannot see how your comment is helpful to the opening poster's question, to me or anybody else who recently came across this problem. I got this problem after doing an update. It appears that rviz in Fuerte just doesn't work in 10.04 and I believe it is beneficial to make others aware of it

I have encountered the same problem!!

I believe an update to my ROS installation is the cause of the problem on Ubuntu 10.04 as you suspected. I have tried to reinstall ROS.

Since nobody else has raised this issue yet, I suppose it is just a problem with 10.04? If so, upgrading to a later release may help. However, I'm not able to upgrade my work PC to 11.10 or 12.04 yet.

This should work:

$ rosrun image_view extract_images image:=/gscam/image_raw _image_transport:=compressed

I followed the linked image and video data export tutorial: http://www.ros.org/wiki/rosbag/Tutorials/Exporting%20image%20and%20video%20data

However, I only save the compressed video to the bag file. From the following warning and error, I can see that I set an incorrect topic /gscam/image_raw/compressed, however, /gscam/image_raw only obviously would not work because only the compressed topic is published.

[ WARN] [1314815531.598786851]: [image_transport] It looks like you are trying to subscribe directly to a transport-specific image topic '/gscam/image_raw/compressed', in which case you will likely get a connection error. Try subscribing to the base topic '/gscam/image_raw' instead with parameter ~image_transport set to 'compressed' (on the command line, _image_transport:=compressed). See http://ros.org/wiki/image_transport for details.

[ERROR] [1314815532.042773170]: Client [/extract] wants topic /gscam/image_raw/compressed to have datatype/md5sum [sensor_msgs/Image/060021388200f6f0f447d0fcd9c64743], but our version has [sensor_msgs/CompressedImage/8f7a12909da2c9d3332d540a0977563f]. Dropping connection

My question is, how can I specify to export the compressed video stream?

Many Thanks!

Try video/x-raw-yuv or put ffmpegcolorspace as the last parameter.

After some more searching, I believe I need to perform some kind of interlacing to alternate between the images from the top field and bottom field. Haven't figured out how to do that yet..

Meanwhile, I have resorted to cropping and resizing. I'm sure this is wrong, but I'm doing this until I figure out how to interlace the video.

GSCAM_CONFIG="v4l2src device=/dev/video0 ! videocrop top=0 left=0 right=0 bottom=288 ! videoscale ! video/x-raw-yuv,width=720,height=576 ! ffmpegcolorspace"

Hi,

I am trying to use GSCAM to capture video from a composite video input through a ViewCast Osprey 230 analogue video capture card.

I have set GSCAM_CONFIG to:

GSCAM_CONFIG="v4l2src device=/dev/video0 ! video/x-raw-rgb ! ffmpegcolorspace"

And viewing the video through image_view

rosrun image_view image_view image:=/gscam/image_view

The problem is the image is duplicated. I only get this problem running when using gscam and the capture card, a USB webcam I have tested works fine. I presume that I need to alter GSCAM_CONFIG but I have not been able to find the correct configuration yet.

Screenshot of my problem:

Any help would be much appreciated!

Thanks