If you are looking for the of this video, it is likely a clip shared on a forum or social media site. Since these IDs are unique to specific uploads, you can sometimes find the original post by searching the exact string on the platform where you first saw it.
These specific filenames often appear when a user downloads a video using a browser extension or a third-party downloader . Because the original uploader didn't give the file a "real" name (like "Vacation.mp4"), your computer saves it using the cryptic internal ID assigned by the server. 0h147u4bt2fstxh24b4p0_source-erlURZ9j.mp4
The system creates different versions of the video for various internet speeds. The "source" tag in your filename suggests this is the original high-quality version before it was compressed for mobile viewing. If you are looking for the of this