But even when I was using Downthemall, it used to rename the file, but this last two weeks before updating the Savefrom extension even downthemall stopped renaming. What caused that?

Okay, I looked into it further. When I'm downloading video by just clicking on various resolution options, i.e., downloading through inbuilt firefox downloader, the clip retains name of the video, but when I'm directing it through download extension (I'm using Download Master, previously DownThemAll) or right clicking on it and downloading through context menu, the name is "videoplayback"Untitled.jpg

Uninstalled extension, cleared complete history with cookies and cache, reinstalled extension, tried download and still it saves with "videoplayback"