Show HN: I reverse engineered Apple's video wallpapers (github.com)
364 points by kageroumado 16 hours ago
Ever since Apple introduced their video wallpapers I wanted to be able to put custom videos there. I decided to reverse engineer and see what I can do.
I built Phosphene to sell it, but the existing competitors were polished enough that the time it would have taken to catch up wasn't going to pay off. So I'm open-sourcing it.
WallpaperExtensionKit.framework is what powers macOS wallpapers. It controls what’s shows in the Settings app. It took a lot of trial and error to replicate the behavior, but the result is that your custom wallpapers appear alongside everything else. I wanted to have an “add” button there too, but I couldn’t find a way to do so, so there’s a companion app that will put your video where it needs to be.
Unlike Apple's Aerials, the video keeps playing on the desktop (not just the lock screen). The renderer drives AVSampleBufferDisplayLayer directly with PTS-offset gapless looping, and pauses or downshifts based on thermal state, battery level, brightness, and window occlusion.
It’s free and works well.
encore2097 15 hours ago
Very neat. I was confused at first, I was like you can download the video screensavers.. why scrape the frames. Then I saw your comment and read I can use my own videos for desktop and lock screen. Great work! Dont bury the lede! A title with the hook of what and how would be super helpful!
cwizou 3 hours ago
Oh wow, that's seriously awesome. I did manage to reverse engineer the private screensaver `.appex` framework and make it work for Aerial 4 (I released a sample project/documentation last week here alongside v4 for those who want : https://github.com/AerialScreensaver/AppexSaverMinimal).
I also tried the same with Wallpaper appexes, the reversing seemed easy enough, but WallpaperAgent refused to load them, so I still use the classic trick of using my own window with a video player on top of the wallpaper, and below the icons.
I will have a look and check what I missed.
frr149 23 minutes ago
One of the first things I removed from my Mac was the 45 gb (sic) worth of wallpaper videos.
buildbot 14 hours ago
As much (fairly well deserved) hate as Tahoe gets, the video wallpapers and transparency are such a fun Windows Vista vibe I get nostalgia. Time to set this up with the Vista waterfall wallpaper and reallllyyy feel like it’s 2007!
_kb 13 hours ago
What do you mean Windows Vista "nostalgia"? That makes me feel a little long in the horn.
Springtime 12 hours ago
> That makes me feel a little long in the horn
I see what you did there :)
ChrisMarshallNY 7 hours ago
geerlingguy 12 hours ago
There are likely a number of folks on this forum now who were born after Vista was released.
_kb 12 hours ago
harrouet 4 hours ago
Vista is what made me get my first Mac. I hope Apple does not make the same mistake.
samat 11 hours ago
Still burned they did not ship winFS then
breppp 10 hours ago
ebbi 13 hours ago
guy_holding_shoulder.jpg
jermaustin1 3 hours ago
My big problem with Tahoe, is the lock screen animation stutters and freezes CONSTANTLY. I'm on an M3 Pro. If I can watch 4K video with no dropped frames, a simple video background should work as well, and if it doesn't, it shouldn't exist.
radley 17 minutes ago
Are you using a Studio Monitor? Lock screen videos are incompatible with Settings > Displays > Refresh rate > Adaptive. You have to use a fixed frame rate (60 or 120 Hz).
asimovDev 7 hours ago
https://windowswallpaper.miraheze.org/wiki/Windows_Vista
which waterfall are you talking about? i am also surprised to see how many wallpapers were apparently available on Vista. All I remember is the default green gradient thingie and I think I had the bamboo forest on at some point
dspillett 6 hours ago
> All I remember is the default green gradient thingie and…
IIRC at that time users were split fairly completely into three types: those who customised their OS look a lot, sometimes spending far too much time on it (I was one of them back then), those who had developed a preferred look and just kept that as much as possible between OS changes, and those who just used the defaults and got on with whatever else. This means the other wallpaper that someone at MS put effort into collecting together hardly ever got seen: many users kept the one default, and almost all who didn't had something that they chose from other sources. Maybe the other included images might have seen the light of day more often if there had been an explicit “choose your wallpaper” prompt as part of user on-boarding.
riddlemethat 13 hours ago
I’m imagining dozens of people worldwide sharing your nostalgia for Vista.
Gigachad 13 hours ago
It's called frutiger aero now. Lot of people very bored with modern safe design nostalgic for when tech and UI was weird and bold.
voidUpdate 8 hours ago
darkwater 6 hours ago
zaps 13 hours ago
“Good old Vista. People give it a bad press but I’m never upgrading, why would I? It just feels like a good pair of jeans.”
wpm 12 hours ago
The moving wallpapers are near the first few times but I can't turn it off. I had to dig deep into WallpaperKit (I mean really? It's a friggin wallpaper) to find the static last frame of the wooshy moving BS.
postalcoder 13 hours ago
Wow, thank you for this. I've been working on a screensaver suite but LegacyScreenSaver is so janky. I was hoping someone would figure out apple's private wallpaper framework and you did!
cwizou 3 hours ago
As far as I can tell this is for WallpaperAgent, an extension to `com.apple.wallpaper` that are ran by WallpaperAgent on the desktop. For screensavers check my other post, I posted a sample the private screensaver api to bypass that.
Apple's uses both for their own "Aerials" and they have a sync system to share the position between the screensaver player and the desktop player.
mikestaas 12 hours ago
OMG, LegacyScreenSaver is such a memory hog!
musicale 13 hours ago
Apple's best video wallpaper is "Macintosh". I am interested in how it works.
futhey 12 hours ago
Same! I distinctly remember seeing portions of this wallpaper that led me to believe it's procedurally generated and not simply a collection of video files, and had to rewatch it to confirm. There are several points where the date and time match the system date and time down to the second.
fphilipe 11 hours ago
It features the current date and time with seconds, so it must be rendered on the fly.
troybetz 10 hours ago
tharropoulos 6 hours ago
Really nice work. We went down a similar rabbit hole recently and reverse engineered the Aerials catalogue to figure out how Apple wires this stuff up, so seeing another open source project doing this is great. The detail I love most and one I can't replicate on our own tool is how the animation persists between the login window and the live desktop. We built phonto as a cross platform take on the same idea, https://github.com/museslabs/phonto. I was about to start writing an article on the whole reverse engineering process and this might be the nudge I needed to start working on it.
arkh 6 hours ago
Reminds me how windows 98 allowed using a HTML page as background. Said HTML could include videos.
somat 4 hours ago
And then there is X11, whatever program you want can be set to the root window.
Anyhow, on topic, that windows 98 active desktop was the most unstable part of an already shaky OS. First thing to turn off when installing a new system. I mean, it would still crash if you looked at it wrong. But at least it was not dying for the fun of it anymore.
netsharc an hour ago
Geez, teen me loved the shininess of Active Desktop, although my Pentium 100 couldn't run it smoothly at all...
ellisd 7 hours ago
Amazing, can’t wait to try this out!
On a similar note, I’d love to replace Aerials on tvOS with my own videos. I have yet to figure out how to craft a working data feed that the tvOS will accept using the secret mode that I believe is used in the retail store displays.
jon-wood 2 hours ago
I suspect the retail stores are using autonomous single app mode, which allows an app deployed on an MDM managed device to take control and force itself to the foreground, disabling screen sleep and other things. I briefly did some reading around it recently when wondering about putting some sort of dashboard on my TV while idle.
fps-hero 5 hours ago
I find it weird today that we are still fascinated by video wall papers.
This was literally my first hack I did in high school in 2005. Doing something I’d never seen done before, a video wallpaper.
Step one, grab a handle to the video memory serving the wall paper. My “game trainer cheats” experience served me well. That was easy.
I had to figure out the hard way that per pixel calculations are extremely CPU taxing, the YUV to RGB video color space conversion. With a pirated Intel compiler I could get the naive blit into memory videy background working.
But then I wondered how other video apps were working so efficiently?
They used a GPU overlay! How it worked is you’d designate a color on your screen as the overlay color, and, when the screen was rendered, any pixel that was the overlay color was swapped with the full screen rendered video. I forget the specifics, it was some directX api. So, set the wallpaper to the hottest hot pink, run the renderer, and bobs your uncle, video wallpaper.
Everyone I showed this to was amazed, I really though I was on to something! Trouble was, I couldn’t get the damn thing to run on other people’s computers!
Little did I know or understand about the dreaded VCruntime redistributable. It wasn’t until 10 years later when I started working in industry I learned about “software distribution”. Linux makes it too easy, windows makes it too hard, static linking everything that isn’t network facing is probably the right approach.
I was so annoyed when Vista had the video wallpaper feature. “Man I was doing this years ago!”.
jbs789 5 hours ago
So in summary… it’s fun when you do it but “weird” when others do the same.
This is life. We discover things for ourselves, on our own time.
kageroumado 14 hours ago
The app now has a landing page with a download link and you can also see my other projects: the largest one is Refrax browser, but I also have many other small utility apps!
ggrelet 7 hours ago
How did you bring up the page so quick? And what helped you design it?
blazarquasar 7 hours ago
It’s entirely designed by claude. Looks like every claude website out there.
divan 7 hours ago
And how did you style it like Anthropic design system? :D
sixeyes 6 hours ago
frieren spotted!
also, nice typography.
wanoir 15 hours ago
So cool! This reminds me I wanted to try setting a custom video background with some footage i had. Didn’t even realize it wasn’t natively supported till i saw this!
kageroumado 14 hours ago
Thank you! I’m glad you like it
echelon_musk 4 hours ago
You're not the first.
ventana 8 hours ago
Nice project, thank you for sharing!
Out of curiosity: how much did you need to steer Claude while working on this project, and how long did it have?
Asking partly because I see "Co-Authored-By: Claude Opus 4.7 (1M context) <[email protected]>", and partly because I keep hearing "so what do you do with all these agents", and this is a good example of what people do with all these agents.
kageroumado 8 hours ago
Not much, Claude was trying different things on their own for hours. It was Opus 4.6, this public release was done by 4.7
shideneyu 7 hours ago
Neat job. And that's interesting to see how it works. I hope to see apple connectivity being reversed engineered too on day
duchanjo an hour ago
Wow, this is really awesome.
dostick 6 hours ago
How did you steer Claude for strict concurrency, can you share the CLAUDE.md?
werdnapk 5 hours ago
Where did they say they used AI for this?
u_fucking_dork 4 hours ago
mgaunard 14 hours ago
Are there specific video wallpaper sets I can download that leverage these features?
kageroumado 14 hours ago
You can use any website that lets you download video wallpapers, or you can make one yourself. Any video can be played
mgaunard 9 hours ago
well I'd specifically want one that's well-designed to make use of the various features you pointed out: highlight battery level, thermals etc.
buildbot 14 hours ago
I vote the Vista wallpapers personally; feels just right.
p0w3n3d 4 hours ago
Wow that's great work! Thanks!
ChrisMarshallNY 15 hours ago
Very cool!
However, it may definitely get broken by Apple, as you note.
kageroumado 15 hours ago
I don’t think they’ll touch this part anytime soon. It’s been unchanged for a few years now, they certainly have other priorities.
ChrisMarshallNY 15 hours ago
Good on ya.
I won't use it, myself, because I can't deal with wallpaper moving behind my work (I also can't listen to music, while I work. Maybe it's a "generational" thing). Also, I use a 49-inch ultrawide, so it might be vomit-inducing.
I remember some other utility that played wallpaper videos, but it wasn't anywhere near as nicely done.
dylan604 14 hours ago
crimsontech 6 hours ago
markdown 14 hours ago
These damned wallpapers gave me my worst experience with Apple. MacOS would delete them and redownload automatically over and over again, using almost a terrabyte of data per week.
And I wasn't even using video wallpapers at the time.
Just discovered I had no internet 3 days into the month as my ISP had cut me off. Had to dig deep and spend hours I'll never get back trying to find out where all the data was going.
Here's a thread I just found now that shows others having similar issues: https://www.reddit.com/r/MacOS/comments/1ii38g8/macbook_wall...
kageroumado 14 hours ago
This app injects itself directly into Apple’s actual pipeline, so your videos won’t get removed or changed. It’s not just an automated replacer of Apple’s own videos.
w-ll 14 hours ago
remember when windows had html wallpapers. brb gonaa agent something that i hope doenst supply chain my entire life
hunter2_ 12 hours ago
The little IE4 widgets called "active desktop"?
throw310822 9 hours ago
You could set a full-screen, interactive browser page as the backdrop of your desktop. Not sure what communication it was allowed to have with the desktop events, but I always thought it was a clever hack that could have been explored and expanded further.
Novosell 7 hours ago
sixeyes 6 hours ago
manuisin 13 hours ago
Woah, thank you! Just checking these will keep on working on the lock screen and as screen savers too?
kageroumado 13 hours ago
The video will keep playing on the lock screen, but screen savers are a different thing. You can have the same video as your wallpaper and screen saver though.
contingencies 10 hours ago
Suggested monetization strategy: porn.
amelius 4 hours ago
Much better than ads in every way, yes.
nashashmi 13 hours ago
Title should be prefixed with show hn:
dang 13 hours ago
I had the same thought and just did that, and your comment was the next thing I saw :)
daemonologist 13 hours ago
I wonder about this when I see someone post their own work without the Show HN prefix - is it always supposed to be a Show? (Enforcement/community objection to the lack thereof doesn't seem to be very strenuous, if so. Or, maybe it gets fixed after a little while and I haven't noticed.)