When I use e.g. hls.js or video.js with HLS extension
http://www.mediaelementjs.com/
https://video-dev.github.io/hls.js/demo/
"save video as" item in context menu is disabled. I'd like to know why? Since JS loaded BLOB put to src of video element doesn't disable the "save video as" item.
Seems it's due use of media source extension (MSE) e.g.: