log in to OF using chrome, goto MoreTools - Developer Tools then switch to Network tab
Now goto the message/video you want to download. then click play. be sure its on the highest quality for playback. if its not, switch it and refresh then go back to the video and hit play. what you're looking for in the network log is a file named 'Source'
here is an example. it'll have a ton of url after the mp4 as well. just right click the link/file show in the network tab and select open in new tab. it'll open video and the video itself should now have a 3 dot menu in the bottom right that you can click and one of the options will be download. save the file, post to here to share and prosper.
