The Treasure Hunt of Increased Difficulty, day 3

Next up, that sound file:

From playing NASCOM games, I guessed that the first blip of noise was probably a header. The rest of the data doesn’t sound like code, though, it sounds like a picture. I only know of one standard for transmitting pictures through audio: SSTV. The example on Wikipedia sounds similar, so I installed QSSTV from a ham radio site*.

To get the sound into the decoder, I played around trying to be clever with UNIX pipes, but in the end resorted to holding my headphones next to the microphone. Charlie wandered over to see what I was doing.

What do I get for all my trouble?

Trollollollolloll.

A trollface**.

I glared at Charlie while the trollface finished. Other SSTV users get pictures transmitted from the ISS and all kinds of cool stuff, and my first SSTV picture is this?? Clearly the whole thing is another red herring and…

…the trollface completed, but the sound carried on. There’s more data here than is specified in the header. I threw it into Audacity to have a look.

Yay Audacity.

It looks like there are two pictures here, but the second one doesn’t have a header.

Ah, but there’s a header-type blip at the end…

… it’s reversed. Ha. I reversed it and played it through the decoder again.

Umm...??

It’s some kind of flowchart on a psychedelic background. I am mystified.

As for the cute cat picture, I suspected steganography and started playing about with hex editors and binary file comparisons. ”Too low-level” says Charlie.

Restate my assumptions:
I have a piece of paper with HTML code that makes a brown website.
I have a USB stick with an apparently empty partition (not bootable, checked that).
I have a picture of a cat being chased by creepers.
I have a psychadelic flowchart.
I have a map.

I’m stuck.

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* Unintentional subchallenge: this SSTV program is a few years old and uses a deprecated sound system. Solution: ALSA OSS backwards compatibility script aoss.

** If you are not familiar with this meme, in context this means approximately: I have fooled you into getting all worked up and doing a whole lot of work for nothing.

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