For years, I've been frustrated by the lack of customisation of macOS. In particular the Lock Screen which supports animated wallpapers, but only ones provided by Apple. There's never been a way to add your own personal videos.
I decided to figure out how to solve this, and the result is Backdrop 2.0. Backdrop is my Live Wallpaper app for Mac, it can play video wallpapers on your desktop. And now it can play on your Lock Screen too.
The core technical challenge, as you can imagine, came from trying to do something that Apple otherwise does not allow. However, through extensive reverse engineering of the macOS wallpaper system, I figured out a way to provide Backdrop wallpapers to the system in a way that allows them to play on the lock screen, and even appear in a custom section in System Settings.
I'm here all day to answer any questions—especially about the reverse engineering process, the challenges of integrating with macOS, or the experience of being an indie Mac developer.
Would love to hear your thoughts and feedback.
All you have to do is have a video you want to use, download one of apple's through settings, go to the location of the downloaded background (I don't remember where that is right now but a quick google search would take care of this), rename your file to the name of apple's file and then replace it.
Mac will act as if this video is the right video and use it without complaints. Until apple starts doing any checksum checks on these files I doubt this method will break anytime soon.
This has been working flawlessly for me for a while now.
This may take some finagling to make sure that your video file is not so large that your Mac can't handle it and that you are using the right format. But it is not hard to do.
Backdrop uses a more advanced approach that ensures that it works seamlessly across reboots and macOS updates.
Famous last words.
Watch as this is used for malware persistence through a code execution exploit. Then Apple will start verifying the file content.
On Linux, I can just compile software myself if I need to make changes. But usually most software is configurable enough that I don't need too.
On OSX, I feel like I'm helpless. I've found very little people writing about their experiences, the tools they use, their workflows, the reverse engineered data structures etc. Can you share how you approached this?
The fact that title bars on OSX aren't a fixed size drives me crazy every single day. I looked into it briefly and realized somehow everything I know about other platforms is basically useless.
[0] https://windhawk.net/
My current workflow is to run Hopper, export assembly files and then throw various agents (Gemini, Claude etc) at them to learn more or validate my theories. It's surprisingly effective! Maybe I'll write about it.
You can run these days macOS as a virtual machine. I have some experience reverse engineering iMessage. Here I only needed to look into the network requests with some SSL pinning removal.
There are some decompiled libraries of Apple's libraries so it helps. Many tried to reverse engineer macOS/iOS before so there is a helpful amount of knowledge out.
I think the best way is just to open up a decompiler program and just start RE. The decompiled source code contains some metadata such as function names so it is readable.
Are you talking about standalone titlebars or are you including merged/unified titlebars+toolbars? Plain titlebars have a single height and merged unified toolbars have a little bit of variance but not a lot.
Any significant variance beyond those is due to third party developers hiding the standard window chrome and drawing their own. You could probably tweak NSWindow instances to bring back the standard chrome, but it’s going to look strange since it’ll show in addition to the custom chrome.
Do you happen to know which are custom chrome and which are "unified"? It didn't occur to me that other programs could be drawing their own chrome, since they look _mostly_ native(at least to me). On windows, if something was using custom stuff it would just look completely different (i.e winamp).
I guess part of the problem is that I've never done native OSX development, so I don't know what the APIs or native toolkits are like.
I think the main question most would ask is what affordances can you give or details you can share to prove that this will continue working in future versions of the os since the foundations seem brittle.
I use Wallpaper Engine on windows for one purpose mostly to avoid burn in since my monitors are always on but I've grown to like it over the years and would like to try something on mac but would hate to purchase software that stops working or future update comes with a readme of how to "re-enable" it.
I think Backdrop fills a specific need that Apple does not want to cover, much like other utility apps like Bartender etc. It will likely require continuous updates, but I’m not new to that, having supported my Trim Enabler utility all the way from OS X Leopard to current macOS.
Next, can you please reverse engineer spaces (multiple desktops) so we can rename them? Desktop 1, Desktop 2 etc is not very useful.
Separately, if there is something like this already from a reputable MacOS appstore ecosystem i'd appreciate knowing about it from anyone.
Here's a random app I found: https://www.mackiosk.com/