HOW TO USE The goal is to convert your mp4 into a bunch of pictures like jpg, png or any other file type which Scratch would allow you to upload onto the editor. There are a few ways to do this, but for security and safety reasons I strongly urge you not to go to online converters because they have been known to install malware and redirect you to undesirable websites. Please DO NOT go to random converter sites if you don't know if it's safe or not. You should use safer alternatives like Snapinsta or offline ones. An example is FFmpeg, which can be used for both Mac and Windows, but must be downloaded first by installing Homebrew. This can be done by using Terminal if you're on a Mac. If you're on Windows, go to https://ffmpeg.org/download.html to download FFmpeg. Check its documentation for full details on how to use ffpmeg. After you have the necessary software downloaded, use the commands required to compress the mp4 and convert it to a series of pictures. Then go to the Scratch editor and to the "Video player" sprite. In the costumes tab, click "Upload" and upload all the picture files you want to play. Go back to the "Code" tab and drag an "Initialise video" custom block under the "Initialise" block definition. Fill in all the parameters of the custom block and then you should be ready to go.
218 block engine Here is the empty project for anyone who may be interested in creating their own videos.