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how to set framerate of usb_cam above 30FPS?

asked 2018-06-08 07:47:14 -0500

updated 2018-06-08 07:50:58 -0500

I am using this usb_camera. I want to use the frame rate 120FPS 640x480. I passed the parameter <framerate> in launch file. But when i check the average rate of topic `rostopic hz usb_cam/image_raw . its showing 30HZ only. Actually it should be 120 !!!

I also try hardcoding the ros::Rate to 120, but is doesn't effect the output of average rate.

  bool spin(){
   ros::Rate loop_rate(this -> framerate_);
    while (node_.ok())
    {
    if (cam_.is_capturing()) {
    if (!take_and_send_image()) ROS_WARN("USB camera did not respond in time.");
   }
   //ROS_INFO("framerate_ '%i'", framerate_ );
   ros::spinOnce();
   loop_rate.sleep();
}
return true; }

Are there any restrictions on increasing the framerate above 30FPS. When I change the frame rate below 30 is show the changes but not above the 30FPS. My usb_cam launch file parameters are as:

  <node name="usb_cam" pkg="usb_cam" type="usb_cam_node" output="screen" >
<param name="video_device" value="/dev/video0" />
<param name="image_width" value="640" />
<param name="image_height" value="480" />
<param name="pixel_format" value="yuyv" />
<param name="camera_frame_id" value="usb_cam" />
<param name="io_method" value="mmap"/>
<param name="framerate" value="120" />
</node>

How can I change the framerate in usb_cam above 30FPS.

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Comments

Do you see an option to set the framerate that high using guvcview?

lucasw gravatar imagelucasw ( 2018-06-08 10:27:40 -0500 )edit

I want to use with ROS. I think its just a video viewer in linux. if no, please give some link

simbha gravatar imagesimbha ( 2018-06-09 06:11:43 -0500 )edit

I want to use withROS. I think its just a video viewer in linux. if no, please give some link

simbha gravatar imagesimbha ( 2018-06-09 06:11:43 -0500 )edit

If it doesn't work in guvcview then it probably won't work in usb_cam

lucasw gravatar imagelucasw ( 2018-06-09 10:12:46 -0500 )edit

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answered 2018-06-08 22:23:52 -0500

vinaykumarhs2020 gravatar image

You should probably set the pixel_format to MJPG. In the product link you have shared, YUYV supports max 30fps only (make sense because of USB2.0 hardware bandwidth limitation!).

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!!!! This pixel camera is not supported by the camera.

simbha gravatar imagesimbha ( 2018-06-09 06:13:39 -0500 )edit

Yes, Actually pixel value needed to be changed, I check that yuyv support only max 30 FPS. I changed to mjpeg

simbha gravatar imagesimbha ( 2018-07-30 13:41:09 -0500 )edit

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Asked: 2018-06-08 07:47:14 -0500

Seen: 366 times

Last updated: Jun 08 '18