Obfuscated C Rickroll

Code

Here is the code: rr.c

Spoiler Warning

It's already been spoiled in the title! It's really hard to have Rickrolls because ideally they'd surprise people, but it you make it obscure enough for that then people will never be able to discover them.

Requirements

This requires a terminal emulator that supports 24-bit ANSI colors. These days most Linux terminal emulators do, including stock xterm (at least on Debian).

There is sound too! On a Debian system at least if you have 
    /usr/bin/aplay
it will attempt to pipe the sound into it at the default 8kHz/8-bit unsigned. If aplay is not detected it will write the sound to the file "r.raw" which you can then try to play on your sound program of choice, or if you have a SUN machine, cat it to /dev/audio.

Obfuscation

It was so hard to get this to fit in the size requirements that I stopped obfuscating once I made it fit.

Attempts to make things look cooler or shrink things more only seemed to make things bigger somehow, due to the complex size accounting rules for the competition.

The graphics are RLE compressed and using a base-64 like variant.
The sound is two-channels using a very simple custom tracker-like format. Though in the end each pattern is done once. Even though some patterns repeat it would have taken more code than it would save to implement that and there wasn't enough room!

Background

Hopefully it's obvious what this is. I wish I had more space, I could have made it sneakier and also had a few more frames of animation.

It's about half animation, half music right now. I should have optimized the music better. An additional frame of animation was 256 bytes but I had to remove it to fix the music code.

Believe it or not this is actually a rough port of an Atari 2600 version of this program.

popen() drama

The code tries to popen() /usr/bin/aplay for sound, and you can pipe in the raw sound data. I thought it would be nice to detect if that's not available and create a file instead. But it turns out on Linux it's not possible to get a file-not-found error with popen(). It can only really tell if the shell fork failed, not if the exec() hit file-not-found. I find the manpage misleading and am working on getting an update to address this.
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