What is a ".madesktop" file and how can I access its data?

Here what I did:

1) open /System/Library/Desktop Pictures/Big Sur Aerial.madesktop with TextEdit

2) get the path from the xml. In my case:

<string>/System/Library/Desktop Pictures/.thumbnails/Big Sur Aerial.heic</string>   

3) with Terminal launch this command:

open -a Finder "/System/Library/Desktop Pictures/.thumbnails/"    

4) Assuming all photos have already been downloaded from the Desktops & Screen Saver settings, searching in the entire hd the names from the thumbnails folder I found that the destination of all downloaded photos is:

/Users/__your-username__/Library/Application Support/com.apple.mobileAssetDesktop/

The other photos are stored in:

• /System/Library/Desktop Pictures
• /Library/Desktop Pictures

That appears to be the pointer to the thumbnails since the desktops must be downloaded.

I think the downloaded images are in a uniqueID folder in:

/System/Library/AssetsV2/com_apple_MobileAsset_DesktopPicture/

dHYSICS wrote:

... If anyone has any info on how these new types of files work and how to access their data, that would be immensely helpful...

You initiate the download by clicking on the cloud symbol on the thumbnail of course...within Desktops & Screen Saver; then you should find them in your Finder folder as well as System Preferences.

The older Desktop image can be found, Finder>Go>Go To Folder, copy & paste:

/Library/Desktop Pictures

The new Images after downloaded from within System Preferences can then be found, copy and paste:

/System/Library/Desktop Pictures

it seems you can still drag a copy to your desktop if you are looking for alternate location...

I guess if necessary you can piece together the complete path from the .XML mentioned above to download the .heic from Apples Content Distribution Network, but this seems laborious

for example: Big Sur 6016 x 6016

http://updates-http.cdn-apple.com/2021/mobileassets/071-34545/7E2884C0-2F21-4028-B22E-2EA162B35135/com_apple_MobileAsset_DesktopPicture/98b5bd24c8bb188ec6101ea415ec049fdd03de84.zip

Sooner are later they will show up on the interwebs,

for example Every Default macOS Wallpaper – in Glorious 6K Resolution

Barney-15E wrote:

Does no-one else have the downloaded image files stored at the path I indicated?

It does seem once downloaded(?) yes they appear nested in those folders— as well as accompany the others in the

/System/Library/Desktop Pictures

but maybe I am mistaken, it all seems a bit obtuse to me...

https://photos.google.com/share/AF1QipNNQyeVrqxBdNmBkq9ILswizuj-RYJFNt5GlxJZ90Y6hx0okrVSLKSnmFFbX7j5Mg?key=RV8tSXVJVGdfS1RIQUI0Q3RZZVhlTmw0WmhFZ2V3

I have those files in the same location:

And they do appear to be links to the HEIC thumbnails of the same name:

Does no-one else have the downloaded image files stored at the path I indicated?

This worked! I had to create a new folder tho, but no prob, at least I have my beloved wallpapers back :)