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637 points robinhouston | 11 comments | | HN request time: 1.27s | source | bottom
1. dvt ◴[] No.36209812[source]
For those that are curious, these are the messages: https://imgur.com/a/y0mXbAk

Decoded using:

    ffmpeg -i input.mp4 -vf tmix=frames=36:weights="1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1" output.mp4
    ffmpeg -i output.mp4 -vf "curves=all='0/0 0.05/1 1/1'" bright.mp4
We need to use the second command, as frame averaging in ffmpeg lowers luminosity. There's probably a way to cleverly get around this, but I'm no ffmpeg expert. The secrets are: "WE LOVE YOU," some alien heads, "UNIVERSE IS THE GATE," and "MIND IS THE LOCK (?—the last word is a bit hard to read)." Pretty neat, fun puzzle, though there's probably ways to make it tougher to solve in the context of something like a hacker tournament (as the negative space is a dead giveaway).
replies(5): >>36211083 #>>36211199 #>>36212896 #>>36213682 #>>36228779 #
2. pera ◴[] No.36211083[source]
Hah that's cool, reminds me a little bit to those LED message fans
3. xattt ◴[] No.36211199[source]
Mad respect for your solution, but how do you get to this point where you can look at a thing and say “oh yeah, it’s XYZ”?
replies(1): >>36216379 #
4. ◴[] No.36212896[source]
5. MrPoush ◴[] No.36213682[source]
A couple of quick optimizations:

- If weights are repeated, you only need to specify the last unique one

- You can chain filters using a comma

- You can drop that last point in the curve

  ffmpeg -i input.mp4 -vf tmix=frames=36:weights="1",curves=all='0/0 0.05/1' output.mp4
replies(1): >>36216351 #
6. dvt ◴[] No.36216351[source]
> You can chain filters using a comma

Haha, I knew there was some way of doing this, but I couldn't remember how (tried semicolons which didn't work), thanks :)

7. dvt ◴[] No.36216379[source]
> how do you get to this point where you can look at a thing and say “oh yeah, it’s XYZ”?

What do you mean exactly?

replies(1): >>36218848 #
8. quibono ◴[] No.36218848{3}[source]
I think GP meant: how do you go from watching the obfuscated video to going, "To see the message I need to use mix=frames=36 with the following weights..."
replies(1): >>36219038 #
9. dvt ◴[] No.36219038{4}[source]
Oh, well the weight was going to be 1 since I needed the frames need to be fully overlayed, and I randomly ended up at 36, since I just kept upping the frames until I got a good-enough image via trial & error. Then I had to fix the gamma, because it ended up being "smeared," which is exactly what I wanted, but extremely dark and hard to see.
replies(1): >>36219242 #
10. BizarroLand ◴[] No.36219242{5}[source]
I've learned that a lot of what we think of as art or mastery is just the end result of trying shit and then remembering what works.
11. yieldcrv ◴[] No.36228779[source]
thank you! I was very frustrated by this whole thing

Like, you want us to take 150ug just to see your puzzle? Well that could be fun in the right context, not on HN though