Zero-Copy is a Lie We Tell Ourselves (and Rust)

The Pre-Mortem

I was reading the post-mortem of the CrowdStrike outage. You know the one. The one where a C++ NULL pointer dereference turned the global economy into a screensaver for 48 hours.

I laughed.

I didn’t laugh because it was funny—hospitals were closed, planes were grounded, and somewhere a junior engineer was vomiting into a trash can. I laughed because I recognized the hubris. I recognized the specific flavor of arrogance that leads an engineer to say: “I don’t need a bounds check here. I know what I’m doing. I’m writing Native Code.”

And then I looked at my own terminal.

I was working on Gausian_native_editor. My “Native” editor. My homage to performance. My temple of speed.

And staring back at me was this commit:

ed827dc - “feat(preview): wire NV12 zero-copy path with GpuYuv + bind group rebuilds”

“Zero-copy.” “Native.” “GPU.”

These are the same lies. They are the siren songs of the modern programmer. They are the words we whisper to ourselves when we want to believe that this time, it will be different. This time, we won’t just be gluing together three Electron instances and a Python script with JSON.

But it’s a lie. It’s all a lie.

The “Native” Trap

Let’s talk about the word “Native” for a second. It’s right there in the name of the project: Gausian_native_editor.

Why did I put it there? Why do you put it there?

Because we are traumatized. That’s why.

We are a generation of engineers who have been beaten into submission by the browser. We have spent the last decade watching our 32GB MacBook Pros choke to death on a chat application. We have accepted that “performance” means “only takes 3 seconds to respond to a keypress.”

So when we start a side project, we say: “No more. This one will be Native. This one will be written in Rust (or C++, or Zig, or whatever the cool kids are using to hurt themselves this week). It will run on the bare metal. It will be glorious.”

It reminds me of the C++ STL wars back in the late 90s.

I was working at Amazon around 2002. (Yes, here comes the Amazon story. Grab a drink).

Back then, “Native” meant C++. And C++ was… well, it was C++. It was a language designed to make you feel smart while simultaneously ensuring that you would never, ever finish your project.

We had this service—I won’t say which one, but if you bought a book between 1999 and 2003, you hit it—that was written in Perl. Perl! Remember Perl? It was the duct tape of the internet. It was ugly, it was write-only, and it worked. It ran the entire internet.

But there was this one engineer—let’s call him “Jeff” (not that Jeff)—who decided that Perl was too slow. “It’s not Native,” he said. “We need to rewrite it in C++ using the new Templates.”

Now, for the uninitiated, C++ Templates in 2002 were not a tool. They were a weapon. They were a way to generate compiler error messages that were longer than the Odyssey and significantly harder to interpret.

Jeff spent six months rewriting this service. He optimized everything. He used custom allocators. He played tricks with pointer arithmetic that were technically legal but morally reprehensible.

And when he finally deployed it?

It was 4ms faster.

Four. Milliseconds.

The Perl script took 200ms (mostly database waits). The C++ monster took 196ms.

But here’s the kicker: The C++ version crashed every 14 hours because of a memory leak in a “smart” pointer implementation that Jeff wrote himself because he didn’t trust the standard library. And it took 45 minutes to compile. And nobody else on the team could understand the code because it looked like ASCII art of a train wreck.

The Perl script? It could be patched in production using vi.

The lesson I learned then, and the lesson I apparently forgot when I named this repo Gausian_native_editor, is that “Native” comes with a tax. A heavy tax. You pay for that performance with your sanity. You pay for it with build times. You pay for it with complexity.

The Google/Amazon Tangent: “Big Company” Infrastructure

This is the thing about working at a place like Google or Amazon. You get spoiled. You get warped.

At Google, if you want to process video, you don’t write a video editor. You write a configuration file for a Borg job that spins up 10,000 instances of a transcoder that was written by a team of 50 PhDs who have done nothing but study H.264 quantization matrices since 1995.

You don’t worry about “Zero-Copy.” You worry about “Zero-Effort.”

There’s an infrastructure for everything.

• Need to build? Blaze (Bazel) handles it.
• Need to store 5 Petabytes? Colossus handles it.
• Need to handle a race condition? Spanner handles it (mostly).

You start to believe that software engineering is just assembling these Lego blocks. “I’ll just take the VideoIngestionService and pipe it to the FrameAnalysisService…”

But then… you leave.

You go out into the “Real World.” You decide to build your own startup, or your own open-source project. You sit down at your laptop, vim open, ready to conquer the world.

And you realize: I don’t have a VideoIngestionService.

I don’t have a build system. I don’t have a distributed file system. I don’t even have a standard library that agrees on what a “String” is (looking at you, C++).

You are naked in the wilderness, armed only with a compiler and a StackOverflow account.

And that’s when the madness sets in. That’s when you decide to implement your own “Zero-Copy NV12 Path” because you think, “How hard can it be? Google does it.”

Google has 30,000 engineers. You have a weekend and a pot of coffee.

The Myth of Performance (and Electron’s Revenge)

It is deeply ironic that we obsess over things like “Zero-Copy” in our native apps, while simultaneously running Slack, Discord, Spotify, and VS Code on the same machine.

My Gausian editor is fighting for every CPU cycle, trying to save a memcpy here and a buffer allocation there.

Meanwhile, Slack is using 4GB of RAM to display a spinning emoji.

And the users? They don love us for it. They sit there with their fans spinning like jet engines, happy as clams.

There is a profound disconnect between what we, as engineers, value (efficiency, purity, correctness) and what the market values (features, shipping, emojis).

“Zero-Copy” is a badge of honor for us. It’s a way of saying, “I understand computer architecture. I understand the bus. I respect the memory bandwidth.”

But the universe doesn’t care. The universe favors the messy. The universe favors the Electron app that ships on three platforms in a week, even if it does burn a hole in your lap.

So why do I do it? Why am I rewriting Gausian in Rust? Why am I fighting with bind group rebuilds and GpuYuv?

Because I’m stubborn. And because, deep down, I still want to be Jeff. I still want to save those 4 milliseconds.

Even if it kills me.

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The Technical Descent into Madness (Or: Why NV12 is the Devil’s Spreadsheet)

So, back to the code. Back to the abyss.

The commit in question—ed827dc—claims to wire up a “Zero-Copy NV12 path”.

For the uninitiated (and I envy your innocence, I really do), let me explain what NV12 is.

Most people think a digital image is Red, Green, and Blue. RGB. Simple. Elegant. Like a child’s finger painting. But video engineers? Video engineers hate simplicity. Simplicity is inefficient. Simplicity takes up bandwidth.

So, decades ago, some guys with thick glasses and slide rules decided that humans are stupid. Specifically, they decided that the human eye is stupid. “Hey,” they said, “The human eye is really bad at seeing color resolution, but really good at seeing brightness.”

So they invented YUV.

• Y is Luma (Brightness). The Black and White image.
• U and V are Chroma (Color).

And then they said: “Since humans are stupid, let’s just throw away 75% of the color information. Nobody will notice.”

This is 4:2:0 subsampling. It is the reason your red text looks fuzzy on a compressed JPEG. It is the reason I drink.

NV12 is a specific flavor of this madness. It keeps the Y plane (brightness) as one big block of memory. And then, for the color, it interweaves U and V bytes like a zipper: UVUVUVUV.

Why? Because it aligns better with GPU memory architectures? No. Because some hardware decoder engineer in 1998 wanted to save a pointer dereference, and now I have to deal with it until the sun explodes.

The Wrapper Hell: Rust vs. FFmpeg

Now, Gausian is written in Rust. Rust is a language designed by people who looked at C++ and said, “This is too dangerous,” and then looked at Haskell and said, “This is too useless,” and settled somewhere in the middle, creating a language that is essentially Bureaucracy-as-a-Service.

Rust demands correctness. It demands that you prove, mathematically, that you own the memory you are touching.

FFmpeg, on the other hand, is written in C. C is the honey badger of languages. C doesn’t care. C will let you cast a void* to a function pointer, execute it, and overwrite your own boot sector, all while smiling.

Combining the two is like trying to schedule a meeting between a German train conductor (Rust) and a raccoon on meth (FFmpeg).

I used a wrapper crate. ffmpeg-next. Or maybe it was rffmpeg. Or rusty-ffmpeg. They are all the same. They are all lies.

They promise you a safe, Rust-idiomatic interface. “Look!” they say. “It’s a frame.data(0)! It returns a slice! It’s safe!”

But look at the code. Look at the unsafe blocks hidden inside.

When you ask FFmpeg for a frame, it points to a buffer in a pool that was allocated by malloc three layers deep in a C library that hasn’t changed since the Bush administration. Rust has no idea when that memory will be freed. Rust thinks it has a lifetime. FFmpeg thinks lifetimes are for weaklings.

So you end up with code like this (and I am paraphrasing my own shame here):

// SAFETY: I promised the compiler that this pointer is valid // because I read the FFmpeg documentation from 2011 and I // am praying to the gods of undefined behavior. let y_plane = unsafe { slice::from_raw_parts(frame.data[0], stride * height) };

This is not software engineering. This is distinct un-engineering. This is taking a beautiful, safe skyscraper and replacing the structural steel with duct tape and hope.

The “Zero-Copy” Lie

And this brings us to the “Zero-Copy” featured in the commit.

Zero-Copy is a term we use to signal virtue. “I didn’t copy the data! I am efficient! I am saving the planet!”

But let’s trace the path of a video frame in Gausian.

1. Disk: The video file sits on your SSD.
2. OS Kernel: You read the file. The Kernel copies it from disk to the Page Cache. (Copy #1).
3. Application: You read it into a userspace buffer. (Copy #2, unless you mmap, which you didn’t, because you’re lazy).
4. FFmpeg: The demuxer parses it and copies packets. (Copy #3).
5. Decoder: The hardware decoder (VAAPI/VideoToolbox) decodes the bitstream. It writes the NV12 frame to GPU Memory or inaccessible Driver Memory.
6. The “Zero-Copy” Step: You want to show this frame in your editor.
   • If the frame is on the GPU, and your editor is using WGPU (which Gausian is), you can theoretically just bind it.
   • BUT WAIT.
   • The decoder output usually has padding (stride).
   • WGPU textures need specific alignment.
   • The format might be tiled (Intel) or swizzled (Apple).

So what do you do?

You write a Compute Shader to “fix” the data. You copy the NV12 data from the “Decoder Texture” to a “Renderable Texture.”

THAT IS A COPY.

You lied. The commit message is a lie. I lied to myself.

I spent three days fighting the borrow checker, wrapping AVFrame in Arc<Mutex<UnsafeCell<T>>>, writing custom Drop implementations to ensure I didn’t leak GPU handles… all to implement a “Zero-Copy” path that actually copies the data, just on the GPU instead of the CPU.

A Memo to the Team (If I Had One)

To: Engineering Team (me, myself, and the cat) From: The Architect Subject: RE: The Definition of “Native” Performance

It has come to my attention that we are congratulating ourselves on the recent “Zero-Copy” implementation.

I would like to remind everyone of the Second Law of Thermodynamics: Entropy always increases.

Every abstraction you add—every Arc, every wrapper struct, every wgpu::BindGroup—is entropy. You are adding chaos to the system. You are turning ordered electricity into heat.

The user clicks “Play.” The user expects the video to move. The user does not care that you used a wgpu::BufferUsages::COPY_DST instead of a COPY_SRC.

But I care.

And because I care, I have decided that for the next sprint, we will be rewriting the decoder loop in hand-written Assembly.

Also, I have disabled the coffee machine. It now requires you to manually acknowledge the memory address of the water boiler before dispensing.

Regards, The Architect

The “Decoder Problem” (Commit dd52fbb)

Speaking of entropy, let’s look at commit dd52fbb: “decoder problem is fixed! finally”.

“Finally.”

That word does a lot of heavy lifting.

If you look at the diff, it’s a one-line change.

- pts: frame.pts + pts: frame.best_effort_timestamp

I spent four days debugging “video lag.” I wrote a profiler. I instrumented the entire pipeline with tracing. I questioned my career choices. I considered becoming a goat farmer.

The problem? FFmpeg has multiple timestamps.

• pts: Presentation Timestamp.
• dts: Decoding Timestamp.
• best_effort_timestamp: The timestamp FFmpeg guesses you probably want because the file is corrupted garbage.

My test video was some random MP4 I downloaded from YouTube in 2014. The metadata was broken. pts was missing for half the frames.

So my “Zero-Copy,” “Native,” “High-Performance” editor was dropping frames and stuttering like a 1920s film projector because I trusted the file.

Rule #1 of The Architect: never trust the input. The input is malicious. The input hates you. The input is trying to segfault your soul.

I changed pts to best_effort_timestamp. It worked.

I felt no joy. Only a hollow emptiness. I had defeated the dragon, but only by realizing the dragon was just a pile of dirty JSON in a trench coat.

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The Societal Implications of Lag

I want to pivot for a moment. I want to talk about Lag.

In the gaming world, lag is an annoyance. In the video editing world, lag is a catastrophe. But in the world of The Architect, lag is a Moral Failure.

When you move your mouse, and the cursor on the screen takes 50 milliseconds to follow, that is not a technical limitation. That is a violation of the social contract between the machine and the human.

The 30fps Insult

There is a pervasive myth—perpetuated by cinema apologists and people who buy cheap HDMI cables—that 24 or 30 frames per second is “cinematic.”

“The human eye can only see 30 fps,” they say.

This is a lie.

The human eye is a biological photon detector evolved over millions of years to detect the motion of a predator in the tall grass. If a tiger moved at 30fps, we would all be dead. We would have been eaten by the buffering artifacts of the Pleistocene era.

When I see a UI that renders at 30fps, or a video editor that drops frames when I scrub the timeline, I don’t see “hardware limitations.” I see laziness. I see a developer who decided that my time—my biological imperative to perceive reality in real-time—was less important than their desire to use a Garbage Collector.

The “Kingdom of Nouns” Returns

Steve Yegge once wrote about the “Kingdom of Nouns”—the Java-centric worldview where everything is an Object wrapped in a Factory, managed by a Singleton.

But in 2026, we have moved beyond the Kingdom of Nouns. We are now in the Kingdom of Abstractions.

Why is Gausian lagging? Why is CamSniff slow?

Because we are running on a stack that looks like a geological layer cake of bad decisions.

1. The Silicon: It performs branch prediction. It guesses what code you want to run. If it guesses wrong, it flushes the pipeline and sulks for 100 cycles.
2. The Kernel: It schedules your thread. But wait! Spotify needs to update its “Now Playing” notification. Context switch! Cache mishit!
3. The Drivers: The NVIDIA driver decides to re-clock the GPU because it thinks you are watching a spreadsheet.
4. The Window Manager: The compositor grabs your frame, copies it (see Part 2), composites it with a transparent blur effect that nobody asked for, and waits for VSync.
5. The Runtime: If you are in Electron/Python/Java, the GC decides now is a great time to count how many objects you created since the last mouse click.

We are not writing software. We are shouting instructions into a cave and hoping an echo comes back before the user gets bored.

A Memo to Management (Re: The new Slack integration)

To: Product Management From: The Architect Subject: RE: Feature Request - “Real-time Collaboration” in the Editor

I reviewed your PRD for “Real-time Collaboration.” You want users to see each other’s cursors.

I have a counter-proposal.

Instead of implementing Operational Transforms (OT) or Conflict-Free Replicated Data Types (CRDTs), which would require me to trust a WebSocket connection maintained by a cloud provider whose name rhymes with “Damazon,” I propose we implement Real-time Judgment.

When a user makes a bad edit, the editor should not sync it to the cloud. Instead, it should lock the keyboard.

It should display a modal dialog: “I see you are trying to use a Dissolve transition. Are you sure? Dissolve transitions are the Comic Sans of video editing.”

If they proceed, we add 200ms of artificial latency to every subsequent keypress.

This is not a bug. It is a feature. We are training the user via negative reinforcement. We are Pavlov’s Developer.

Also, I have deprecated the “Undo” button. “Undo” implies that mistakes are reversible. This is a dangerous worldview. In my architecture, mistakes are permanent.

Regards, The Architect

The Human Perception Limits

There is research—obscure research, possibly written by me under a pseudonym—that suggests the human brain perceives reality in quantums of roughly 13 milliseconds.

This means that any software responding in under 13ms feels “instant.” It feels like an extension of the self. Any software responding in >100ms feels like a “tool.” It feels external. Clunky.

And any software responding in >300ms feels like an insult.

Gausian—in its current, Rusty, Zero-Copy-ish state—scrubs 4K video at about 40ms per frame. This is… acceptable. It is on the border of “Tool” and “Self.”

But every time I add a “feature”—a UI widget, a logging statement, a safety check—that number creeps up. 41ms. 42ms.

It is a slow death. It is the death of 1,000 cuts.

And this brings me to the profound realization I had while staring at that Gausian repo.

We are not building video editors. We are building latency monitors.

Every feature request is just someone asking for more latency. “Can we add AI stabilization?” -> +20ms. “Can we add cloud backup?” -> +50ms (and a network thread that blocks the UI). “Can we add a cute animation when the file opens?” -> I will delete your badge access.

The job of The Architect is not to add features. It is to stand at the gates of the repository with a flaming sword and scream: “NO.”

NO, you cannot add a dependency. NO, you cannot use a RefCell. NO, you cannot “just put it in a background thread.” Background threads are where data goes to die in a race condition.

And NO, we will not support 30fps. We support 60fps or we support nothing. If the user’s computer cannot handle 60fps, the application should uninstall itself out of shame.

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The Conclusion (The Heat Death of the Universe)

We have reached the end.

We have traversed the valley of “Native” promises, climbed the mountain of NV12 subsampling, and swum through the swamp of FFmpeg wrappers.

And what have we learned?

We have learned that Zero-Copy is an asymptote.

You can get close. You can get infinitely close. You can use IOUring, and mmap, and DMA-BUF. You can write your own kernel modules. You can solder wires directly to the PCIe bus.

But somewhere, somehow, the Universe will exact its toll. A cache line will miss. A cosmic ray will flip a bit. A Project Manager will ask for a “share to TikTok” button.

And you will copy.

Acceptance

I looked at that final commit in the log:

aa9bc11 - “WIP: partial split of main.rs (stalled)”

“(stalled)”

That is the most honest commit message in the history of software.

Every project is just “stalled” eventually. Gausian is not a video editor. It is a monument. It is a cathedral built to the glory of my own ego, constructed from the bones of unsafe blocks and broken dreams.

Will I finish it? No. Will I rewrite the decoder loop in Assembly next weekend? Probably.

Because we are engineers. And we are sick.

We are sick with the disease of optimization. We look at a chaotic, messy, inefficient universe—a universe of Electron apps and 30fps interactions—and we say: “I can fix this.”

“I can do it purely.” “I can do it natively.” “I can do it with Zero Copies.”

It is a lie. But it is a beautiful lie.

The Final Decree

So, as The Architect of this doomed facility, I am issuing a final decree regarding the Gausian_native_editor.

1. Repository Status: The repo is now Read-Only. Not via GitHub settings, but because I have encrypted the hard drive and swallowed the key.
2. Legacy Support: If you want to use the editor, you must compile it yourself. The build script now requires a living sacrifice (a 3.5” floppy disk burned in a ritual fire).
3. The “Nuke” Option: I am taking a page from CamSniff. I am refactoring main.rs. I am replacing the entire event loop with a single panic!("Entropy Won.");.

One Last Commit

Before I go, I have one last commit to push.

It’s not a fix. It’s not a feature. It’s a README update.

## Installation 1. Don't. ## Usage 1. Open your window. 2. Throw your computer out. 3. Go outside. 4. Perceive reality at infinite FPS with zero latency. 5. (Note: The outdoor rendering engine has excessive bloom and no dark mode).

Zero copies. Zero lag. Perfect fidelity.

Of course, the user story for “Being Outside” is terrible. There’s no Undo button. And the NPCs are annoying.

But at least the coffee machine works.

[End Rant] [End Transmission] [System Halted]