[Lazer] How to manually add a video to a difficulty:
Press File -> Edit Externally
Once the folder opens, open the difficulty you wanna edit in a suitable text editor
Difficulty files are in the following format: <Artist> - <Title> <Creator> <Difficulty>.osu
Suitable editos: "Editor" (comes with windows), notepad++
In the File scroll to "[Events]"
Now under "//Background and Video events" add the following:
Video,0,"name.type"
- Replace "name" with the name of your video file.
- Replace "type" with your videos filetype (mp4, avi, etc.)
Save the file in the text editor
Repeat process for every difficulty in your folder.
Once done, enter the osu editor again and press "Finish editing and import changes" to apply the added video.