Cowon iAudio T2 Review && Cowon logo editing on Linux

I had been wanting a digital audio player for a while now, since I don’t like to run down the battery on my other devices, which aren’t primarily meant for music.  I looked around, but I couldn’t find anything that was good enough to be worth buying, but was simultaneously cheap enough to justify buying.  As I still haven’t found a job for the summer, the idea was shelved, until my friend mentioned that he was discarding his old player.  Naturally, being the scrounge that I am, I asked if I could have it, and he consented.  The only problem it has is that the OLED screen is rather dim – I presume it’s just wearing out – and aside from that, it’s a nice little gadget.  The model, if you hadn’t guessed from the title, is a Cowon iAudio T2, a fairly generic-looking black rectangular-shaped player about the size of a matchbox.  It is meant to be worn as a pendant, with special earbuds for that purpose, but my friend didn’t have them anymore… oh well.  I was impressed to see that it supports OGG Vorbis audio in the stock firmware, as well as having a few other nice features, namely, a fully adjustable equalizer, and an on-device menu option to switch between USB-mass-storage and MTP modes.

I haven’t tried this last feature yet, but it may be handy.  (See Wikipedia.)  When I first plugged in the device, I noticed a folder on the root of it, called SYSTEM.  I poked around inside, and it seems the device exposes its configuration file, as well as the “screensaver” and animated startup logo files, to the host computer.  I Googled around a bit, and found that the official Windows-only software from Cowon allowed you to change the logo/screensaver, however, given that their flasher got really angry at WINE when I tried to run it on my Linux laptop, I didn’t feel like downloading their music manager app and attempting to beat it into submission just to fiddle with some graphics.

Not to be put off, I pulled out my Hex Editor (Okteta v0.30, from the KDE project – if you haven’t tried it, it’s nice), and delved into the “ss.ilb” file.  I haven’t gotten any code written yet to convert pictures, but it should be trivial; the file format is simple, and here it is for you!  (If someone beats me to coding a Linux converter, please post a comment here with the link.)

Header:

69 41 55 44 49 4F 20 31 36 78 32 34 43 00 00 00 01 00 03 00 E8 03 E8 03 E8 03

This, in ASCII, says “iAUDIO 16×24C”, and then a bunch of bytes, the meaning of which I haven’t figured out yet.  The human-readable portion is easily-enough understood, as each frame of the screensaver animation is 16×24 pixels, and the “C” presumably means “Colour”.  In my simple tests so far, it would seem that fudging the resolution in the header doesn’t (by itself) allow you to use the full 96×64px resolution of the screen.

What follows is three frames of animation, stored by row as raw 16-bit RGB pixel values, with no end-of-{row,frame,file} delimiters.  The file should thus be $091A bytes long, with each frame being $0300 bytes.  I have not conclusively determined whether the 16th bit is used for green, as the screen on my unit is too dim to distinguish subtle variations in colour, but in the absence of other information, this seems reasonable to assume for now.

I haven’t poked around in the logo.ilb file yet, but it is probably much the same, with the exception of a higher resolution, and more frames.  I will update or post again, as necessary, when I look into that.  So, I hope this helps some other Linux users get their own lousy, pixelated screensavers on the iAUDIO T2 without having to resort to Windows (gasp!) or bundled, proprietary software.  I am much more excited about the animated startup splash (logo.ilb), as it actually looks decent, and is of more benefit to the user.

Update:  I realized I probably should have uploaded an example of the file itself, but as trivial as it is, it is technically copyrighted, so I’ll wait until I have a personal example before I do.  I think you can find some examples on Cowon’s forums, though.

Happy Hacking,

- The Ffej