Show HN: I reverse engineered Apple's video wallpapers

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!

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!

What do you mean Windows Vista "nostalgia"? That makes me feel a little long in the horn.

> That makes me feel a little long in the horn

I see what you did there :)

I attended the Longhorn event, where they played Director scripts, and told us it was “live code.”

There are likely a number of folks on this forum now who were born after Vista was released.

Nope. 2007 is like 2 or 3 years ago, tops.

Vista released over 19 years ago.

You missed the joke.

Still burned they did not ship winFS then

Good thing it eventually grew to replace NTFS

Vista is what made me get my first Mac. I hope Apple does not make the same mistake.

guy_holding_shoulder.jpg

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.

I have this problem a few times a day on my corporate M4 Pro when I lock the screen... with 60Hz set. It happens when the two security monitoring app corporate insists on are scanning harder b/c the screensaver kicked in. My personal macbook pro is fine.

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).

I’m imagining dozens of people worldwide sharing your nostalgia for Vista.

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.

The funniest thing about the "frutiger aero" thing is that it looks nothing like how I remember vista looking

It’s the same idea but dialed up to 11. Apple’s Liquid Glass is a more restrained application of the style.

Let a sufficient amount of time pass, and what people knew in their children/teenage years will be remembered with nostalgia.

“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.”

It wasn’t a horrible OS. It just broke XP’s “it runs on practically anything” before the hardware was really there. And 7 was, as we all know, the most perfect Windows has ever been. Windows 7 Media Center was a magnificent DVR and a great movie-playing box.

This so depends on the timing. XP was a memory hog when it came out for that generation's hardwarw

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

> 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.

I'm feeling nostalgic for ~1998 when I ran xscreensaver hacks in the background on the root X window (so the "desktop" I guess)

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.

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!

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.

OMG, LegacyScreenSaver is such a memory hog!

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.

Thank you! The way it works is that the video playback is shared between the lock screen and the desktop, and Apple’s framework transparently switches the surface it’s displayed to.

Apple's best video wallpaper is "Macintosh". I am interested in how it works.

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.

It features the current date and time with seconds, so it must be rendered on the fly.

The assets and some? of the scripting for it are in a bundle at:

/System/Library/ExtensionKit/Extensions/WallpaperMacintoshExtension.appex

Can see the time and date being added here I think:

System6ControlPanel.program

    //
    //  System 6 Control Panel
    //  Macintosh 40th Anniversary
    //
    //  Copyright © 2024 Apple. All rights reserved.
    //
    //----------------------------------------------

    start simultaneous
        scale out
        let image = "System6ControlPanel"
        ...
        ...
        add time at 267, 165 name "Geneva12"
        add date at 274, 239 name "Geneva12"
    end simultaneous

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...

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.

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.

Reminds me how windows 98 allowed using a HTML page as background. Said HTML could include videos.

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.

Geez, teen me loved the shininess of Active Desktop, although my Pentium 100 couldn't run it smoothly at all...

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!”.

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.

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!

Thank you! I’m glad you like it

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!

https://kagerou.glass/phosphene/

https://kagerou.glass

How did you bring up the page so quick? And what helped you design it?

It’s entirely designed by claude. Looks like every claude website out there.

Yes, I told Claude to design it to their taste, I just provided the screenshots and the video.

And how did you style it like Anthropic design system? :D

frieren spotted!

also, nice typography.

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.

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.

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) <noreply@anthropic.com>", 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.

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

Are there specific video wallpaper sets I can download that leverage these features?

You can use any website that lets you download video wallpapers, or you can make one yourself. Any video can be played

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.

I vote the Vista wallpapers personally; feels just right.

Very nice, thank you for this! I’ve been wishing for a way to control when the wallpaper freezes. Can your app also keep it playing on the lock screen?

this is stated in the post my dude. not even at the github link, just like, a few paragraphs in.

> the video keeps playing on the desktop (not just the lock screen)

My dude, that doesn’t really answer the question unless you infer more than people usually mean. This is about changing the behavior of the video stopping after considerable time, the default behavior is that it keeps playing for a good while (while on the desktop it stops close to immediately), which I assume is what they are referring to by “just the lock screen”.

You're not the first.

https://news.ycombinator.com/item?id=45247396

That architecture diagram looks like claude did it. Not complaining though, good documentation has been a great side effect of using them.

Claude is in the contributor list on the repo.

Very cool!

However, it may definitely get broken by Apple, as you note.

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.

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.

Which generation is that? I'm a Gen Xer. I can't work without music, but specific music without lyrics for my brain to try to follow.

I’m a “late boomer” (born in ‘62).

It doesn't move while you work, its just the lock screen and when you log in.

It’s actually configurable. You can make it keep playing if you want to.

I understand, now.

I originally thought that this was an extension to keep a video running in the background.

It simply allows you to add your own videos to the built-in Apple ones (much more useful to me).

Cool. Thanks!

Neat job. And that's interesting to see how it works. I hope to see apple connectivity being reversed engineered too on day

It didn't work so well for me but I was able to refactor it into something that does work for me. Thank you.

Could you please open a PR with your refactor? This way everyone can benefit

Wow that's great work! Thanks!

Thank you! I’m glad you like it

One of the first things I removed from my Mac was the 45 gb (sic) worth of wallpaper videos.

How did you steer Claude for strict concurrency, can you share the CLAUDE.md?

My repo has a skill that describes most of my approaches in more detail.

https://pastebin.com/XLhjr4pf https://github.com/kageroumado/swiftui-macos-skill

Where did they say they used AI for this?

https://news.ycombinator.com/item?id=48219128

Nice work but would love to see a demo in readme

Claude or not its really coool ideation matter

remember when windows had html wallpapers. brb gonaa agent something that i hope doenst supply chain my entire life

The little IE4 widgets called "active desktop"?

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.

Making even the background run electron, eh?

Unfortunately it was IE.

i remember setting a html with a flash file and it did track the cursor accurately for some fun effects. couldn't keep it like that due to resource use but yeah, it was fun!

icons and text would get single-color backdrops though. no transparency back to the html

Wow, this is really awesome.

Woah, thank you! Just checking these will keep on working on the lock screen and as screen savers too?

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.

Suggested monetization strategy: porn.

Much better than ads in every way, yes.

great work

Title should be prefixed with show hn:

I had the same thought and just did that, and your comment was the next thing I saw :)

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.)