What does this mean? well: It displays an MP4, or an animated webp, webm file. The MovieBox thingy can show at least 3 Megabytes of a movie. If the file is higher than that, it will trim the file to ~3 megabytes to be displayed.

Link to the blocks

How to upload a file to a MovieBox sprite:
1. Hover over the new sprite button
2. Click the upload file into the moviebox sprite
3. Done, just done
You can do these steps over and over

Edit 1: The sprite will become the MovieBox if start movie has triggered, and any blocks can effect the movie, if it effects the sprite.
For more information, Click or visit this reply For more info on the blocks, Visit here. This also might pair well with this post I guess
Edit 2: I edited to show MP4 files, because one person requested it. Link here: https://scratch.mit.edu/discuss/post/9035861/
Also, use

(Report :: looks) 

if you see someone upload an inappropriate file using the extension!

Animated gifs and webp's are already a thing as far as I know. The only problem with mp4s is that its both sound and video in one file

ChristianScratcher1 wrote:

Animated gifs and webp's are already a thing as far as I know. The only problem with mp4s is that its both sound and video in one file

Oh okay

bump

"Sorry, you have to wait 60 seconds between posts."

Bump?

b u m p

IGMSTPDNGO

"Sorry, you have to wait 60 seconds between posts."

Topic bump 2.0

"Sorry, you have to wait 60 seconds between posts."

MSTTDNGLTT

TTWGU

Bump! Why is no one repliging!?

Mup

Dump

Support. But okay, 11 bumps?

Support, cool idea. I see this being used. My stupid phone cant upload movies or videos period…

littlejoeywhoiscool wrote:

Support. But okay, 11 bumps?

because no one was responding (1 bump per 24 hours, sorry for the inconvenience)

"Tasty Bump from Bump Games co." - from some random dude

Bump it up

ChristianScratcher1 wrote:

(#2)
Animated gifs and webp's are already a thing as far as I know. The only problem with mp4s is that its both sound and video in one file

Problem is when you convert MP4s to GIFs and / or WEBPs, the filesize can sometimes be too big to be imported into Scratch as the filesize usually gets bigger.

CaptFrIEdshrimp wrote:

(#16)

littlejoeywhoiscool wrote:

Support. But okay, 11 bumps?

because no one was responding (1 bump per 24 hours, sorry for the inconvenience)

Well if nobody responds, it might simply be that there isn't that much support for the suggestion.

floppasyay wrote:

ChristianScratcher1 wrote:

(#2)
Animated gifs and webp's are already a thing as far as I know. The only problem with mp4s is that its both sound and video in one file

Problem is when you convert MP4s to GIFs and / or WEBPs, the filesize can sometimes be too big to be imported into Scratch as the filesize usually gets bigger.

CaptFrIEdshrimp wrote:

(#16)

littlejoeywhoiscool wrote:

Support. But okay, 11 bumps?

because no one was responding (1 bump per 24 hours, sorry for the inconvenience)

Well if nobody responds, it might simply be that there isn't that much support for the suggestion.

I am going to keep bumping this topic up (also the bloxcks one too) until it get rejected, or become part of scratch

Edit 1: i also included the triming part if the file is to big into like ~3 megabytes