Hi Ton,

Correct me if I'm wrong here, do you mean you want embed the link 192.168.0.5/content/1.mp4 in the video link section? As you go to video embed it will scrape and crawl the data from the link page either its have og tag where analogically should working as Facebook.
Perhaps, you can upload the video instead of embed it

further more I cannot find the location of path to ffmpeg, I put the folder in several directories. path is r/w rights.

-> Can you consult with your web hosting provider the exact path to your ffmpeg? and if the path is correct it will not shows the error 'the path you specified is invalid. please enter a different path to ffmpeg' under the path section.
And make sure the ffmpeg version is meet with minimum requirement here:
https://stackideas.com/docs/easysocial/administrators/welcome/minimum-requirements