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Scaevoluson An update on Steam / GOG changes for OpenTTD

That's a narrow fair use exception. Many of these open game engines are effectively 1:1 decompilations of the original games, and it would be shocking if they were not effectively copyrighted the same as the original.

I don't think this has been tested in court, but the recent flood of Nintendo game decompilations is likely to change that.

Scaevoluson Microsoft's 'unhackable' Xbox One has been hacked by 'Bliss'

Microsoft released a video that covers effectively all of the Xbox One security system, and it's referred to extensively in the talk. The specific methods of glitching don't require any insider knowledge.

Scaevoluson The AI Vampire

You're reading more dismissal than I wrote.

Most businesses can and many businesses do run efficiently out of shared spreadsheets. Choosing the processes well is the hard part, but there's just not much computational complexity in the execution, nor more data than can be easily processed by a single machine.

Scaevoluson The AI Vampire

Many engineers get paid a lot of money to write low-complexity code gluing things together and tweaking features according to customer requirements.

When the difficulty of a task is neatly encompassed in a 200 word ticket and the implementation lacks much engineering challenge, AI can pretty reliably write the code-- mediocre code for mediocre challenges.

A huge fraction of the software economy runs on CRUD and some business logic. There just isn't much complexity inherent in any of the feature sets.

Scaevoluson Show HN: A luma dependent chroma compression algorithm (image compression)

JPEG XL also incorporates Chroma from Luma. It's a standard coding tool in modern codecs.

Scaevoluson Animated AVIF for the Modern Web

Hardware video decoding APIs often have significantly more latency than software decoders, to the point that it's a noticeable several hundred milliseconds of delay. If they have this delay, they're unusable for images.

Scaevoluson Elasticsearch was never a database

You have that backwards. GFS was replaced by Colossus ca. 2010, and largely functions as blob storage with append-only semantics for modification. BigTable is a KV store, and the row size limits (256MB) make it unsuitable for blob storage. GCS is built on top of Spanner (metadata, small files) and Colossus (bulk data storage).

But that's besides the point. When people say "RDBMS" or "filesystem" they mean the full suite of SQL queries and POSIX semantics-- neither of which you get with KV stores like BigTable or distributed storage like Colossus.

The simplest example of POSIX semantics that are rapidly discarded is the "fast folder move" operation. This is difficult to impossible to achieve when you have keys representing the full path of the file, and is generally easier to implement with hierarchical directory entries. However, many applications are absolutely fine with the semantics of "write entire file, read file, delete file", which enables huge simplifications and optimizations!

Scaevoluson Personal thoughts/notes from working on Zootopia 2

Most companies doing CGI work, both in games and movies, are quite open about their technical details. The whole industry relies on pooled research and development. While the actual code is typically confidential, publishing information serves multiple purposes for the work's publicity, the advancement of the field, the happiness of employees, and company prestige for recruiting people.

Scaevoluson Fabrice Bellard's TS Zip (2024)

When LLMs predict the next token, they actually produce a distribution of the probability of each of the possible next tokens, and the sampler chooses one of them, and not necessarily the most likely one!

If instead you run LLM prediction and then encode the probability of the next token of the input text you want to encode (from the cumulative distribution, a number in [0, 1]) using arithmetic coding, you can run the same operation in reverse to achieve lossless compression.

The tricky part is ensuring that your LLM executes absolutely deterministically, because you need to make sure that the encoder and decoder have the same probability distribution map at each step.

Scaevoluson Show HN: VAM Seek – 2D video navigation grid, 15KB, zero server load

Client-side frame extraction is far too slow to be usable for large volumes of data.

You want to precompute the contact sheets and serve them to users. You can encode them with VP9, mux to IVF format, and use the WebCodec API to decode them in the browser (2000B-3000B per 240x135 frame, so ~3MB/hour for a thumbnail every 4 seconds). Alternatively, you can make the contact sheets with JPEG, but there are dimension restrictions, reflow is slightly fiddly, and it doesn't exploit intra-frame compression.

I made a simple Python/Flask utility for lossless cutting that uses this to present a giant contact sheet to quickly select portions of a video to extract.

Scaevoluson Robotopia: A 3D, first-person, talking simulator

GGML is another neat ML abstraction layer, but I don't think much work has been dedicated to the Windows port.

Scaevoluson Robotopia: A 3D, first-person, talking simulator

Shipping GPU-accelerated ML models in games looks difficult, are there any major examples other than vendor-locked upscaling like DLSS or FSR?

(Yep! https://cod.ifies.com/voxel-visibility/ )

Scaevoluson Robotopia: A 3D, first-person, talking simulator

Are the LLMs run on-device, or does this use cloud compute?

(Off-topic AMA question: Did you see my voxel grid visibility post?)

Scaevoluson enclose.horse

The pre-machine-learning formulations of AI focused on symbolic reasoning through the dual problems of search and logic. Many problems can be reduced to enumerating legal steps, and SAT/SMT/ASP and related systems can churn through those in a highly optimized and genetic manner.

Scaevoluson enclose.horse

Yes, this is the major challenge with solving them with SAT. You can make your solver check and reject these horseless pockets (incrementally rejecting solutions with new clauses), which might be the easiest method, since you might need iteration for maximizing anyways (bare SAT doesn't do "maximize"). To correctly track the flood-fill flow from the horse, you generally need a constraint like reachable(x,y,t) = reachable(nx,ny,t-1) ^ walkable(x,y), and reachable(x,y,0)=is_horse_cell, which adds N^2 additional variables to each cell.

You can more precisely track flows and do maximization with ILP, but that often loses conflict-driven clause learning advantages.

Scaevoluson enclose.horse

The site uses Answer Set Programming with the Clingo engine to compute the optimal solutions for smaller grids. Maximizing grids like this is probably NP-hard.

Note that traditional SAT and SMT solvers are quite inefficient at computing flood-fills.

The ASP specifications it uses to compute optimal solutions are surprisingly short and readable, and look like:

  #const budget=11.
  horse(4,4).
  cell(0,0).
  boundary(0,0).
  cell(0,1).
  boundary(0,1).
  % ...truncated for brevity...
  cell(3,1).
  water(3,1).
  % ...
  
  % Adjacent cells (4-way connectivity)
  adj(R,C, R+1,C) :- cell(R,C), cell(R+1,C).
  adj(R,C, R-1,C) :- cell(R,C), cell(R-1,C).
  adj(R,C, R,C+1) :- cell(R,C), cell(R,C+1).
  adj(R,C, R,C-1) :- cell(R,C), cell(R,C-1).
  
  % Walkable = not water
  walkable(R,C) :- cell(R,C), not water(R,C).
  
  % Choice: place wall on any walkable cell except horse and cherries
  { wall(R,C) } :- walkable(R,C), not horse(R,C), not cherry(R,C).
  
  % Budget constraint (native counting - no bit-blasting!)
  :- #count { R,C : wall(R,C) } > budget.
  
  % Reachability from horse (z = enclosed/reachable cells)
  z(R,C) :- horse(R,C).
  z(R2,C2) :- z(R1,C1), adj(R1,C1, R2,C2), walkable(R2,C2), not wall(  R2,C2).
  
  % Horse cannot reach boundary (would escape)
  :- z(R,C), boundary(R,C).
  
  % Maximize enclosed area (cherries worth +3 bonus = 4 total)
  #maximize { 4,R,C : z(R,C), cherry(R,C) ; 1,R,C : z(R,C), not cherry(  R,C) }.
  
  % Only output wall positions
  #show wall/2.

Scaevoluson I/O is no longer the bottleneck? (2022)

Apple had soldered DDR ram for a long time that was no faster than any other laptop. It's only with the Apple Silicon M1 that it started being notably higher bandwidth.

Scaevoluson Linux is good now

2026 YOLOTD!

Scaevoluson Rainbow Six Siege hacked as players get billions of credits and random bans

https://x.com/vxunderground/status/2005008887234048091

Here's the word on the internet streets:

- THE FIRST GROUP of individuals exploited a Rainbow 6 Siege service allowing them ban players, modify inventory, etc. These individuals did not touch user data (unsure if they even could). They gifted roughly $339,960,000,000,000 worth of in-game currency to players. Ubisoft will perform a roll back to undo the damages. They're probably annoyed. I cannot go into full details at this time how it was achieved.

- A SECOND GROUP of individuals, unrelated to the FIRST GROUP of individuals, exploited a MongoDB instance from Ubisoft, using MongoBleed, which allowed them (in some capacity) to pivot to an internal Git repository. They exfiltrated a large portion of Ubisoft's internal source code. They assert it is data from the 90's - present, including software development kits, multiplayer services, etc. I have medium to high confidence this true. I've confirmed this with multiple parties.

- A THIRD GROUP of individuals claim to have compromised Ubisoft and exfiltrated user data by exploiting MongoDB via MongoBleed. This group is trying to extort Ubisoft. They have a name for their extortion group and are active on Telegram. However, I have been unable to determine the validity of their claims.

- A FOURTH GROUP of individuals assert the SECOND group of individuals are LYING and state the SECOND GROUP has had access to the Ubisoft internal source code for awhile. However, they state the SECOND GROUP is trying to hide behind the FIRST GROUP to masquerade as them and give them a reason to leak the source code in totality. The FIRST GROUP and FOURTH GROUP is frustrated by this

Will the SECOND GROUP leak the source code? Is the SECOND GROUP telling the truth? Did the SECOND GROUP lie and have access to Ubisoft code this whole time? Was it MongoBleed? Will the FIRST GROUP get pinned for this? Who is this mysterious THIRD GROUP? Is this group related to any of the other groups?

Scaevoluson Pfizer ended up passing on my GLP-1 work back in the early '90s (2024)

Self-injecting feels like a scary, painful, dangerous procedure and becomes completely boring by the third repetition.

Scaevoluson SIMD City: Auto-Vectorisation

Auto-vectorization is consistently one of the least predictable optimization passes, which is rather awful, since when it doesn't trigger your functions are suddenly >3x slower. This drives people to more explicit SIMD coding, from direct assembly like in FFMPEG to wrappers providing some cross-platform support like Google's Highway.

It's just really hard to detect and exploit profitable and safe vectorization opportunities. The theory behind some of the optimizers is beautiful, though: https://en.wikipedia.org/wiki/Polytope_model

Scaevoluson We replaced H.264 streaming with JPEG screenshots (and it worked better)

Moonlight is mostly designed to stream your gaming desktop to a portable device or your TV at minimal latency and maximum quality within a LAN. For that, 40Mbps is quite reasonable. It's obviously absurd for mundane VNC/productivity workloads.

Scaevoluson NTP at NIST Boulder Has Lost Power

Note that WWV is a good 60 miles NNE of Boulder on the outskirts of Fort Collins.

Scaevoluson Hacker News front page now, but the titles are honest

You can use fiber optics as an optical delay line too! About 60KB/km at 100Gbps.

https://en.wikipedia.org/wiki/Delay-line_memory

Scaevoluson Using TypeScript to obtain one of the rarest license plates

Especially given how the response time doesn't matter much here! If you're just looking at 2-character license plates, that's 676/5=136 requests to check them all, and you could easily space that out to something like one request per minute to scan the space every two hours.

Scaevoluson Zmij: Faster floating point double-to-string conversion

Is the large significands table (~19KB) an issue for cache contention in practical use, or are only a small range of significands generally accessed?

Scaevoluson No Graphics API

SDL3 is kind of the intersection of features found in DX12/Vulkan 1.0/Metal: if it's not easily supported in all of them, it's not in SDL3-- hence the lack of bindless support. That means you can run on nearly every device in the last 10-15 years.

This "no api" proposal requires hardware from the last 5-10 years :)

Scaevoluson Go's escape analysis and why my function return worked

This could probably be implemented as an expensive comment-driven lint during compilation.

Scaevoluson Extra Instructions Of The 65XX Series CPU (1996)

He went even farther, decapping the CPU and reverse engineering its entire workings to understand how each "undocumented" opcode functioned: https://www.pagetable.com/?p=517

Scaevoluson Detecting AV1-encoded videos with Python

Note that ffprobe can output JSON which is much easier to handle than CSV. I have this snippet in my bashrc:

ffpj() { for f in "$@"; do ffprobe -v quiet -print_format json -show_format -show_streams "$f"; done }