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> A single 1080p raw video frame would be 1080 * 1920 * 1.5 = 3110.4 KB in size

They seem to not understand the fundamentals of what they're working on.

> Chromium's WebSocket implementation, and the WebSocket spec in general, create some especially bad performance pitfalls.

You're doing bulk data transfers into a multiplexed short messaging socket. What exactly did you expect?

> However there's no standard interface for transporting data over shared memory.

Yes there is. It's called /dev/shm. You can use shared memory like a filesystem, and no, you should not be worried about user/kernel space overhead at this point. It's the obvious solution to your problem.

> Instead of the typical two-pointers, we have three pointers in our ring buffer:

You can use two back to back mmap(2) calls to create a ringbuffer which avoids this.

It's pretty funny that they assumed that memory copying was the limiting factor when they're pushing a mere 150MB/s around instead of the various websocket overheads, then jumped right into over-engineering a zero copy ring buffer. I get it, but come on!

>50 GB/s of memory bandwidth is common nowadays[1], and will basically never be the bottleneck for 1080P encoding. Zero copy matters when you're doing something exotic, like Netflix pushing dozens of GB/s from a CDN node.

[1]: https://lemire.me/blog/2024/01/18/how-much-memory-bandwidth-...

I agree with you. The moment they said shared memory, I was thinking /dev/shm. Lots of programming languages have libraries to /dev/shm already.

And since it behaves like filesystem, you can swap it with real filesystem during testing. Very convenient.

I am curious if they tried this already or not and if they did, what problems did they encounter?

well someone will feel like an idiot after reading your facts. This is why education and experience is important. Not just React/rust course and then you are full stack senior :D