I read a lot of documents and forums but I still have questions about the media upload API for direct messages attachments.

Here I can read that the max size allowed for video is: 15 MB, Images 5 MB and GIF 15 MB.
But here I can read that “File size must not exceed 512 MB”

First Question: What is the max size allowed for media tipe video/image/gif ?

Then, here I can read that
“media” “required” “The raw binary file content being uploaded. It must be <= 5 MB, and cannot be used with media_data.”

Second Question: Can I split media files ( images / gifs / videos) in differents chunks of 5MB max size ?

Here I can read that “It is possible to attach the same media asset to multiple Direct Messages. However, you must get users’ express consent to set media as “shared,” and must provide them with clear notice that “shared” media will be viewable by anyone with the media’s URL. See the documented process below for how to set media to “shared.””

Other Questions:
I asume that i can re-use a media ID for more than 1 twit. How long will be able that media ID if I upload it as “shared”? forever? 24 hours?

I can read that “Once a media ID is generated, it must be attached to a Direct Message within 24 hours.”
I asume that I have to use it at least one time in the first 24 hours and then the Media ID is able to be re-used forever. Is that true?