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Transfer video using Wifi

asked 2018-01-09 08:36:22 -0500

Trishant_Roy_221b gravatar image

updated 2018-01-14 14:56:50 -0500

Hey, I am trying to transfer video from one laptop to another for real-time analysis.

I followed the instructions given in the following link:

http://wiki.ros.org/ROS/Tutorials/Mul...

I want to transfer video at 720p.

But there is a lot of lag and also the frame rate received is very less.

Is there a problem with video transfer using Wifi? That shouldn't be the case since there are cameras having internal wifi or drones are also used in concerts, matches for live streaming.

Are their other methods to transfer other than ROS or another method in ROS?

I could only get real-time video when I reduced to 200 X 200 (very less).

Edit: I am using usb_cam package to get webcam data and using rviz to view the video feed.

Thanks.

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answered 2018-01-09 09:22:44 -0500

gvdhoorn gravatar image

Are you using any compression? Or sending raw, uncompressed, full-frame, full-colour 720p frames over a sensor_msgs/Image topic? In the latter case, that could get up to ~ 3.5MB per frame (megabytes, not bits). For 30fps, that would be ~105MB/s. Your wifi probably can't handle that.

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I tried the compression topic as well and that too in 480p. Though the output is better, the issue still persists.

Is there any other possible reason other than due to Wifi? Coz some surveillance cameras do use Wifi to send output to PC/mobile.

Trishant_Roy_221b gravatar image Trishant_Roy_221b  ( 2018-01-14 07:25:53 -0500 )edit

Can you describe what you have used exactly? Edit your original question with the new info. Packages/nodes used, topics, configuration settings, etc.

Note that sending individual frames over sensor_msgs/Image (even if compressed) is always going to be less efficient than a proper video codec.

gvdhoorn gravatar image gvdhoorn  ( 2018-01-14 11:26:19 -0500 )edit

Edited. Yes... that is true...But the video feed should be better like wifi cameras

Trishant_Roy_221b gravatar image Trishant_Roy_221b  ( 2018-01-14 14:59:23 -0500 )edit

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Asked: 2018-01-09 08:36:22 -0500

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Last updated: Jan 14 '18