Since I don't have a blog that's useful for this, I am making this thread to have a place to dump information I discover while developing things, which is not readily available on the net, so that Google can hopefully pick it up for the next person who goes looking for it.
I think it's some Photoshop in-joke. I recall there being some kind of rubber-ducky-related easter egg in some versions, too.
I got the description in >>2 slightly wrong. Here's an updated version, with some thanks to the author of ExifTool for pointing out my mistake:
The Photoshop JPEG APP12 Ducky Format
"Ducky" is the name of a simple metadata format which is written by Photoshop into files when you use the "Save for Web" feature. It's stored in an APP12 marker, starts with the five bytes "Ducky" (without a null byte ,unlike many other markers), and then continues as follows:
2 bytes (big-endian int16): Chunk type
2 bytes (big-endian int16): Chunk size
n bytes: Chunk data
(repeats)
2 bytes: 0x00 0x00, End marker
There are three chunk types I've seen:
Type 1: Quality
4 bytes (big-endian int32): JPEG quality
Type 2: Image description
4 bytes (big-endian int32): Number of characters, should be (Chunk size-4)/2
n-4 bytes: Unicode characters, in big-endian UTF-16 without a BOM.
Type 3: Image copyright
4 bytes (big-endian int32): Number of characters, should be (Chunk size-4)/2
n-4 bytes: Unicode characters, in big-endian UTF-16 without a BOM.
This thread could be interesting
Well, if it's gonna get bumped, I might as well put some more stuff in here.
Earlier, I reverse-engineered a lot of the Soundload protocol that the DS game Bangai-O Spirits uses to send user-created levels to other DSes or to a computer, by using the speaker and mic:
http://code.google.com/p/bangaio-tools/wiki/TechnicalInformation
I was meaning to make a level uploading site that would display level previews and such, but I kind of got distracted by something else before I finished it. There should be some functional code in the SVN, though, for anybody who wants to play with it. Maybe I'll get back to that site later.
Awesome