I made a CTF challenge for this year's BSidesSF CTF where players were given a CDDA audio file (just raw PCM samples) which when burned on a CD-RW would produce an image of the flag. (The idea was not for them to burn the audio, since they'd need to guess my exact CD-RW or else they wouldn't get an image readable enough to be useful. Instead they were supposed to invert the process in software and simulate what a burned disk would look like, in a way that let them adjust disk parameters rapidly until they had a readable image.)
The challenge took me a few weeks to make because "calibrating" a disk (determining the geometry of the pregroove) is incredibly sensitive.
After the CTF I tried really hard to make a repeatable calibration process with the intent of building something releasable. I even ended up measuring the details on every CD-RW and CD-R I could buy on Amazon.
But despite trying very hard, I never did make calibration patterns that were reliable enough that I felt like other people would be willing to go through the process.
It seems someone else has succeeded where I failed. Great to see!
> In 2012, a LightScribe optical drive was successfully used by Maher El-Kady, a graduate of UCLA, to turn a specially prepared graphite oxide layer coated onto a DVD into graphene.[10] El-Kady and Richard Kaner, his lab professor, used an unmodified LightScribe drive. The disc was prepared by coating the disc with an aqueous solution of graphite oxide and allowing it to dry. Areas of the coating illuminated by the LightScribe laser were turned into graphene. Various shapes can be drawn, which allowed the scientist duo essentially to laser-print an ultracapacitor on graphene using consumer-grade technology.
QuantumNomad_ 2 hours ago [-]
Sun used to say “the network is the computer”.
Now you are telling me we could potentially have “the DVD is the computer”. Imagine printing not just a capacitor but a whole PCB and soldered components, putting the innards of like a Raspberry Pi on top of a specially crafted DVD that has said single-board on one side and a readable DVD surface on the opposite side! :D
QuantumNomad_ 8 hours ago [-]
I have a LightScribe compatible external CD/DVD burner. It came with a LightScribe disc that I haven’t taken the plastic off still to this day. Since it only came with a single one I could never decide which one thing to use that one LightScribe disc for, back when I was still burning things on CD and DVD.
sam1714 8 hours ago [-]
You didn't miss much. It took 20-30 minutes each pass, plus the extra cost for the discs.
But even if you were fine with that, it came out too light under actual lighting conditions, even after you burned it twice, which defeats the use case of making it look professionally labeled. For home use, a Sharpie beat it in every way.
TurkTurkleton 7 hours ago [-]
Huh, that wasn't my experience. I mean, it absolutely was slow especially with sufficiently complex labels, but they generally came out fine. Granted, you absolutely couldn't just drop any arbitrary image into the LightScribe software and have it come out looking good, you'd have to mess with the contrast, but black-and-white text and line art would come out fine. And more legible than Sharpie, with my handwriting.
Symbiote 2 hours ago [-]
For a very low-sales side business (my father's hobby) the discs looked sufficiently professional to impress the people buying them — mostly his friends.
I have the same issue in video games. I always end up at the end not having used my unique items because I only have 1.
serf 3 hours ago [-]
i'm like that in anything vaguely RPGish, videogame/board-top/cards/whatever.
if there is a such thing as a potion or anything like it i'll horde it and never use for fear of needing it in the future, well past the last boss or the credits..
alias_neo 50 minutes ago [-]
I've noticed this a few times where I've hoarded items to use later only to find I've finished the game before that challenging "later" arrives.
For some odd reason, the specific game that comes to mind for this was Horizon:Zero Dawn PS4/5.
Conversely, I'm playing Half-Life:Blueshift right now, and I didn't try to save anything, now I've hit a couple of points where I'm out of ammo or health and can't progress without loading an older save.
I had one fun experience in Black Mesa (HL fan-remake) where I was knocked off of the edge of a "cliff" by a large enemy (no spoilers) and it auto-saved mid-air, so it reloaded me falling forever >_<.
I still have a DiscT@2 capable drive running (a Yamaha CRW-F1), though I haven't tried the imaging capability in... geez, 20 years.
Breakthrough 8 hours ago [-]
I had one of these as well... What a trip down memory lane, thanks for sharing.
kixpanganiban 2 hours ago [-]
This is exactly the sort of thing the 2020's are missing. Something tactile and artsy, reminiscent of the early 2000s! Well done to the author
Animats 7 hours ago [-]
I used to have a label system called Neato, which provided round CD labels you could make on a printer, along with a tool to press them accurately onto the non-recording side of a CD-R. There were even transparent labels, so the resulting disk looked like a commercially produced disk.
I've always wondered if this could be used to create 3d holograms.
leni536 28 minutes ago [-]
Me too, but I don't think the resolution is good enough, even on blu-ray.
LeoPanthera 6 hours ago [-]
Is anyone still making new optical drives?
grishka 2 hours ago [-]
Absolutely. And discs as well. I had an x-ray recently and asked them to give me the image so I could take it to a different clinic, and they burned it onto a CD. So I suppose optical media is sort of irreplaceable for medical applications at least.
ale42 1 hours ago [-]
Like floppy disks were in Japan for a long time... and fax machines in other countries.
truncate 5 hours ago [-]
Probably. Bluray still exists, still a popular medium for selling games on PS/Xbox and to certain extent movies to people who like to watch on their high-end equipment.
samplatt 4 hours ago [-]
Sony is discontinuing all the BD disc players,as well as famously discontinuing disc games for the playstation.
XBox is making similar moves but isn't committing 100% to the bit yet.
ig-88ms 3 hours ago [-]
Sony probably hasn't been the OEM for their drives in ages. Microsoft never was.
I'm sure there are still one or two OEMs who build drives.
4 hours ago [-]
jonhohle 6 hours ago [-]
Windows 2000 & XP discs had something like this, but on the label side.
NDlurker 8 hours ago [-]
Wow! Light Scribe on the data side!
Larrikin 8 hours ago [-]
Do they actually play?
sourweasel 7 hours ago [-]
I can't comment on this particular project, but I know that similar projects have allowed adding images to the unused portions of the disc. A given region of the disc cannot be both image and data, but the disc can contain an inner region of data and imagery in the outer unused portion.
jedbrooke 7 hours ago [-]
DVD codec probably allows for a certain amount of error correction to recover from scratches, images can still look readable to humans despite a bit of noise, I wonder if there’s enough overlap there to meet in the middle and have an image that also stores data
Nition 2 hours ago [-]
A bit like those AI images that were also working QR codes from a while back.[1]
Would be a really interesting challenge to find the point where maximally useful data meets a maximally good image. The data goes through layers of encoding to become data on disc, so it wouldn't be easy, but we already have a one-way translation here in this tool.
Do folks here know the data goes “into” the label through the clear plastic?
A fellow xth grader did a science project on this, and I’ll never forget it.
avra 3 hours ago [-]
What do you mean by that?
I don't think the laser writes data into the label usually. There is a reflective layer though, that will be damaged easily when scratching or peeling off the label.
alias_neo 46 minutes ago [-]
I think they're suggesting that the "data holding" layer, is actually the label, not the plastic.
The plastic is purely for protection and rigidity, the "label" is the actual functional part of the disc.
anonym29 8 hours ago [-]
star graph looks very inorganic
kuberwastaken 7 hours ago [-]
That's what happens when your project randomly blows up through a translated tweet haha
weng 3 hours ago [-]
[flagged]
carplaybits 8 hours ago [-]
[flagged]
bronlund 3 hours ago [-]
[flagged]
idoit738 3 hours ago [-]
Anime girls are practically universality accepted in Chinese programmer circles. Look at the members of the Deepseek Harness team in their repo lol
mrheosuper 2 hours ago [-]
it's similar to "programming sock" in Western.
ig-88ms 3 hours ago [-]
It's not you alone. I too find it off-putting and weird. I screams sexist gen-z man to me.
apt-get 2 hours ago [-]
I take it you've hardly ever interacted with queer people under the age of 40, then, because otaku culture is beloved by every demographic :)
prmoustache 2 hours ago [-]
To me all this obsession with girls in high school uniforms screams straight pedophilia and I find it quite disturbing/disgusting to see this being so common in the tech world tbh.
r0l1 3 hours ago [-]
Yeah. I find it really cringe.
cowlevel 7 hours ago [-]
Truly, China has overtaken the Western world in innovation.
I wonder if the disk can still hold data at the same time.
Rendered at 10:24:21 GMT+0000 (Coordinated Universal Time) with Vercel.
The challenge took me a few weeks to make because "calibrating" a disk (determining the geometry of the pregroove) is incredibly sensitive.
After the CTF I tried really hard to make a repeatable calibration process with the intent of building something releasable. I even ended up measuring the details on every CD-RW and CD-R I could buy on Amazon.
But despite trying very hard, I never did make calibration patterns that were reliable enough that I felt like other people would be willing to go through the process.
It seems someone else has succeeded where I failed. Great to see!
> In 2012, a LightScribe optical drive was successfully used by Maher El-Kady, a graduate of UCLA, to turn a specially prepared graphite oxide layer coated onto a DVD into graphene.[10] El-Kady and Richard Kaner, his lab professor, used an unmodified LightScribe drive. The disc was prepared by coating the disc with an aqueous solution of graphite oxide and allowing it to dry. Areas of the coating illuminated by the LightScribe laser were turned into graphene. Various shapes can be drawn, which allowed the scientist duo essentially to laser-print an ultracapacitor on graphene using consumer-grade technology.
Now you are telling me we could potentially have “the DVD is the computer”. Imagine printing not just a capacitor but a whole PCB and soldered components, putting the innards of like a Raspberry Pi on top of a specially crafted DVD that has said single-board on one side and a readable DVD surface on the opposite side! :D
But even if you were fine with that, it came out too light under actual lighting conditions, even after you burned it twice, which defeats the use case of making it look professionally labeled. For home use, a Sharpie beat it in every way.
The disc shown on https://en.wikipedia.org/wiki/LightScribe looks normal.
if there is a such thing as a potion or anything like it i'll horde it and never use for fear of needing it in the future, well past the last boss or the credits..
For some odd reason, the specific game that comes to mind for this was Horizon:Zero Dawn PS4/5.
Conversely, I'm playing Half-Life:Blueshift right now, and I didn't try to save anything, now I've hit a couple of points where I'm out of ammo or health and can't progress without loading an older save.
I had one fun experience in Black Mesa (HL fan-remake) where I was knocked off of the edge of a "cliff" by a large enemy (no spoilers) and it auto-saved mid-air, so it reloaded me falling forever >_<.
This was followed up by Labelflash in 2007(2).
(1) https://en.wikipedia.org/wiki/DiscT@2
(2) https://en.wikipedia.org/wiki/Labelflash
XBox is making similar moves but isn't committing 100% to the bit yet.
Would be a really interesting challenge to find the point where maximally useful data meets a maximally good image. The data goes through layers of encoding to become data on disc, so it wouldn't be easy, but we already have a one-way translation here in this tool.
[1] e.g. https://www.reddit.com/r/StableDiffusion/comments/141hg9x/co...
A fellow xth grader did a science project on this, and I’ll never forget it.
The plastic is purely for protection and rigidity, the "label" is the actual functional part of the disc.
I wonder if the disk can still hold data at the same time.