I'm trying very hard to embed a youtube video into IPB 4 and resize it so it's not so big. 
I know that usually you can post the youtube link and it will embed the video automatically, Unfortunately this isn't working in v4.

Literally the only way I can get a video on the post is by using the Insert other Media button on the bottom right and selecting "insert image from URL"
But I can't adjust the size of the embedment. I wish I could just edit the post in HTML. But doesn't look like I can do that

<----EDIT---->

I've found the "Can post in HTML" option in the user roles settings which allowed me to edit in HTML. Now is there a way to allow users to only embed youtube videos or something? 
Apart from using the "Insert image from URL" button which I doubt they will realize that you can also embed youtube videos with? 
Also, The Youtube link itself method doesn't work. They just show up as a link.

I know that usually you can post the youtube link and it will embed the video automatically, Unfortunately this isn't working in v4.

 

I too would like to know how to automatically embed YT videos and twitter posts

In the test forum I found using the share link in YouTube embeds the video directly but using the url from the browser doesn't work. Hopefully that will be fixed.

As for resizing that used to be controlled in ACP "manage media tag". Not having a test install of 4 I can't verify if the functionality still exists.

 

Youtube and Twitter works fine, just paste url and press enter. http://community.invisionpower.com/forum/15-test-posting-messages/