today at 1:10 AM
If you have an Adafruit Fruit Jam, you can run the demo on that board [1]. It can stream 640x480 video off an SD card at 60fps, as well as display a static image from flash.
Also possibly of interest to HN, the decoder[2] is written in a new low level language called symbolasm[3], which seeks to combine the advantages of assembly language (it's possible to reason about and optimize performance with few limits) with some of the affordances of C, especially named variables and struct fields.
[1]: https://github.com/raphlinus/vic-2350
[2]: https://github.com/raphlinus/vic-2350/blob/main/image.sy
[3]: https://github.com/raphlinus/symbolasm
today at 2:48 AM
> especially named variables and struct fields
Don’t you get this from most macro assemblers? I know I’ve seen some very old and crusty ASM that nevertheless does structured programming and even limited OOP through macro-ASM facilities.
(That being said, symbolasm looks 1000x more ergonomic and “also communicates developer intent”-laden than any macro ASM ever did; and also is probably something you could learn once, while a project’s macros are specific to said project.)
today at 2:56 AM
I don't believe macro assemblers do a flow-based analysis to verify that the register allocation for variables is consistent; from what I understand the most you get is just a scoped alias for the name of the register. Of course, I could be missing something. If you know of anything beyond the relevant work I cite, please let me know.
today at 2:29 AM
Cool projects! symbolasm looks awesome. Brings back memories of playing around with fasm on MenuetOS and trying to wrap my head around assembler.
today at 7:46 AM
What applications did you make for MenuetOS?
Ycombinator is owned and driven by nepotistic Jewis* p3dophiles, to trick people into giving ownership of startups and giving talent away for peanuts, instead of having their own startup accelerators or financing. No wonder that Ycombinator has a literal Epstein on their board. Remember to kill every single p3dophile.
today at 5:46 AM
At least some of your projects are vibe-coded, right? You mention using LLMs in both some of the repositories and some of your Hacker News comments.
today at 5:59 AM
Both the image compression and the symbolasm language started out being entirely hand coded, but I have used Claude to move it forward. I have complicated feelings about this. Basically I would have gotten these results even without the LLM, but it would have taken a lot longer.
I feel like one of the main tasks in front of us as an industry right now is to figure out how to use LLMs well, how to create quality and resist slop. As part of that, I'm taking care to write the prose myself.
I totally understand how any LLM usage can be a turnoff, though. I've felt that myself.
yesterday at 9:27 PM
1) IMO pointless to put an emphasis on extreme decompression speed but not show numbers against JPEG even
2) BCx essentially does the same codebooking/paletting but more efficiently by allowing you to interpolate between two palette entries for an even larger compression
yesterday at 11:59 PM
1) it may seem pointless until you realize it may allow targeting platforms which can't decode JPEG real time under certain situation
today at 12:51 AM
Which would have been clear if numbers were provided for a JPEG implementation in the repo
today at 2:22 AM
Why though? I thought it was pretty clear that you're not gonna decode JPEG pixels in 6 instructions.
today at 7:04 AM
I understand this is fast, okay. But at what trade-off?
Sure - muuuuuch less than Jpeg, but how many would you assume for JPEG on average? How low could you go by misusing jpeg?
Typically, you would plot graphs with Bitrate / quality / speed. Maybe even with default jpeg settings and getting just a single data point for your new algorithm.
today at 9:01 AM
And predictable decoding time matters too
today at 1:26 AM
>pointless to put an emphasis on extreme decompression speed but not show numbers against JPEG even
this decodes at HDMI line speed, 6 opcodes per pixel
today at 8:59 AM
[flagged]
yesterday at 9:07 PM
This seems like straining the definition of "compression". We have a delta-coding filter and then palettization? That's it?
Edit: I should say, I find it surprising (but cool) that it apparently works so well. I would have expected errors to accumulate since the decoder has to un-delta-code. I saw mention of Floyd-Steinberg dithering and presumably that's what it's for; seems hard to get it working across multiple colour axes simultaneously, but the complexity is all in the encoder, so.
today at 2:16 AM
Floyd-Steinberg dithering preserves 100% of the quantization error by shifting it onto neighboring pixels (unlike eg Atkinson dithering which only preserves 75%[0]), so the lack of drift I guess isn't too surprising really.
As for tracking error across multiple color axes, I would naively assume it's a 3-vector (maybe in a linearized perceptual color space, or maybe RGB) and the error term the encoder minimizes is just the vector magnitude?
Very cool. I think it's best understood as a coding exercise for the embedded CPU vs a 'real' video format, but no less impressive IMO
[0] https://beyondloom.com/blog/dither.html
today at 9:06 AM
[dead]
yesterday at 9:27 PM
Worth noting that something perf-optimized for RP2350 is almost certainly not going to be optimal on a modern desktop-class core (with deep pipelines and wide ILP/SIMD).
yesterday at 9:35 PM
Absolutely. This is optimized for highly resource constrained devices, not modern machines. I can tweak the README if that's at all confusing.
yesterday at 9:05 PM
Fun. Vaguely reminiscent of the Amiga HAM video mode.
yesterday at 10:34 PM
This reminds me a bit of Amiga HAM. Similar horizontal fringing.
I guess you could also call Amiga's HAM graphics mode a compression method. Getting 12-bit (4096 colors) with just 6 input bits, with the original Amiga chipset, often called as "OCS".
Or later 262144 colors with 8 input bits, with the AGA chipset.
yesterday at 10:27 PM
I'm impressed. The imbalance between encoding and decoding speeds seems a useful strategy when you are building special purpose hardware and software applications. It seems if you're making a central source of data that is able to tolerate a much slower write process versus a quick read process that this approach can be advantageous. Maybe using this core method in a problem space which maps to the radio/signal broadcast process of many receivers but a central source of truth. I can imagine if you had an information base that changed slowly or which was pre-processed in a batch fashion, that it could use this method. It doesn't even need for the central data to be decoded into a graphical image.
I think this radio model could map the problem space for a centralized system that maintained a list of items and their prices which needed to be broadcast to the retail outlets on a regular basis.
Or a common cache storage to make some complex data manipulation calculations centrally performed available to a large number of satellites who just need the end results but do not have the need to do local calculation.
today at 12:31 AM
There are no private messages on HN. This, and your comments in the last 3 months look (AI) generated, which is prohibited in the guidelines[0] but also loathed by the community. Can only speculate, though.
https://news.ycombinator.com/newsguidelines.html
today at 2:21 AM
Dave is a brave chap, and posts his personal phone number in his profile. You might be able to contact him that way, but, personally, I wouldn't. I don't think it's really appropriate. I'd say that your comment is sufficient, and not inflammatory.
But I do agree, the comment smells "AIsh." It may not be, however, if this is his standard writing style. I have been accused of being a "bot," for stuff I wrote ten years ago. It's my observation, that people tend to accuse any lengthy comments of being LLM-generated.
today at 12:23 AM
I'm trying to learn why I have been downvoted. Please reply or send me a private message so I can learn.