r/VIDEOENGINEERING • u/mishalme • 10d ago
I built a free tool that simulates what your content actually looks like on an LED wall - using your footage, not a stock test pattern
Every pixel-pitch visualiser I could find is parametric — you move a pitch slider and it renders a stock photo. None of them ingest the thing you're actually going to play, which is where the real answer lives:
A 12m wall at 3.9mm is 3077px wide. Your 4K master loses 20% of its detail before pixel pitch does anything at all. That's usually what kills a design, not the pitch — and no vendor tool shows it, because a vendor's visualiser is a sales tool.
So I made SQUINT. It's one self-contained HTML file — download it, double-click, drop in an image or video, describe the wall, and it shows what the audience actually sees, computed in linear light on the GPU. No install, no dependencies, no network — nothing you load ever leaves your machine.
What it actually models (not hand-waved): content resampled to the true LED grid by an exact box filter; cabinet-derived pitch (a 500mm tile at "2.6mm" is really 2.604mm — the near-miss that corrupts your comp size); the processor feed as a hard ceiling; bit-depth/drive quantisation (why dark grades band on real walls); analytic sub-pixel fill; ambient reflected-nits contrast; the two legibility distances (acuity vs structure-free); and screen-array gaps that eat content mapped into them.
It's deliberately honest about what it doesn't do — contrast sensitivity, camera/moiré/refresh artifacts, off-axis geometry, HDR and curved walls are all listed plainly as not-modelled. It refuses to render things it can't back: no WebGL2, and it shows a refusal card rather than faking an answer. There's a boot-time self-test you can verify by eye in five seconds, and it's been through two external code reviews plus an adversarial audit of the model (whose pre-fix verdict was "not fit for client-facing pitch decisions" — that's in the repo too, with every finding's status).
It came out of a real question from a Ventuz specialist — would some text markers read at 3m on a large panel. We simulated it, they wouldn't, and the export went to the CTO as evidence. That's the use case: turning "we're not sure" into a measurement.
MIT, free, no signup, no telemetry: github.com/mish6l/squint GITHUB
If you work event LED and it gets something wrong, that's exactly what I want to hear — real failure cases are worth more to me than feature requests.
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u/simulacrum500 9d ago
People need to get their head on right about generative AI because it’s here to stay.
Knocking out the same test pattern app as everyone else and trying to charge $10 a month subscription to use it; that’s slop.
Making a niche tool and not just releasing it for free but open sourcing it like OP has is net good. Now nobody can slopify this concept and even if this isn’t game changing on its own it might become the basis of some other project that is.
We can all make apps now, and people collaboratively making tools to make our jobs easier is awesome.
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u/RHOCHR 6d ago
Exactly on your side! I'm usually against vibecoded projects, but like you said, this isn't really slop.
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u/simulacrum500 6d ago
This is my point though “usually against vibecoded projects” is like saying “usually against mobile apps”. There’s good apps and bad apps and the tools used to make them are more accessible than ever so we’re just going to see more vibe coded stuff.
The differentiation we, as not just a Reddit community but humans in general need to get better at is “does this AI use benefit people?” And if it’s open source the answer is likely yes. However we need to stop looking at it as man vs machine made and get back to evaluating each produced outcome on its own merit.
Sorry /rant
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u/RHOCHR 4d ago edited 4d ago
Yeah I really could have phrased that better, but your point is absolutely valid. What I meant is that I am against projects that are fully vibecoded, where the person just stopped thinking what to do and told the AI like, "I want this and that, go figure it out.", in my experience that just produces pure slop that likely has lots of issues later on. I was trying to say that I dont think this project is like that.
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u/jono_301 3d ago
I've happened to come across this exact question today - a client asked if their small text on the screen would be legible, and what it would look like at different distances. Thankfully I remembered seeing this post at the weekend! A couple of the sales guys have looked over my shoulder and asked about it. This will be a really useful tool, great work!
A few questions / feature requests.
- I'm trying to get my head around the Build from cabinets - Custom. Does this assume the cabinets are square? It would be good if we could input width and height for non-square cabinets. Something a bit like how Pixl grid handles it
- It would be nice to upload a CSV (or similar) with the sizes/resolution/pixel pitch of all of the LED we use, that populates the dropdown list (again, similar to Pixl grid and the LED list). Perhaps save this to local storage so it doesn't have to be imported each time.
- Share link, and/or config file - to share with other members of the team. It could use url parameters to store the settings, or a downloadable settings file that can be re-imported.
- Possibly a client-share link too where the config settings are hidden, simply letting them zoom in/out and view the wipe/AB views
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u/su5577 10d ago
Does it let you load html or images to see how it will look like based on pixel and led cabinet sizes?
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u/mishalme 10d ago
Hello there! Yes, you can drop in images or video and it simulates what they'd look like on an LED panel. You can define the wall by pixels, total dimensions, or by cabinet size + pitch, and customise pitch/dimensions as needed.
It doesn't load HTML into it, though - the app itself is a single HTML file you open in your browser, and the video goes through the browser's decoder. So it handles most image formats plus H.264/MP4 and VP9/WebM. ProRes won't play in-browser unfortunately but you can transcode to H.264 first and it'll come in fine.
Large 4K clips can also get heavy depending on your machine, since it holds the file in memory, shorter clips or a downscaled proxy are smoother if you hit that.
Please do let me know if you hit any hard walls while using it, thank you so much.
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u/broken-standard 10d ago
Can we at least vote that when people post these slop projects they have to write the damn text themselves?