Ah yep! I just didn't wait long enough. Very cool. Seems like it took a lot of work. And it seems better than other browser-based video editors I've seen in the past, so kudos.
yeah sorry for that long loading and not properly showing indicator, it took long time for me to develop especially because I was trying to learn as much so I usually tried doing something myself for weeks and then finally thinking that was idiot move and using library, webcodecs API is super cool, im hoping they will also add muxing and demuxing to api, though I like ffmpeg because im using it more than just muxing and demuxing in this project