Myst Online: Uru Live KI image bug

From MYSTlore

Since December 2006, the Myst Online: Uru Live client has had a bug with its local storage of KI images, avatar portrait photos, and other images.

[edit] Technical details

Affected images begin with four bytes representing the file size the image would have without those bytes. The purpose of this is unknown; the size was likely meant to go into the file header, rather than the beginning of its body.

Many viewers and editors of JPEG files stumble upon the first four bytes and refuse to read any further, as this file beginning violates JPEG file format specifications. Then again, there are applications that can deal with the images perfectly fine, and in fact produce a completely fixed version automatically. To name a few:

• IrfanView, a free Windows image viewer (primarily) and editor
• GraphicConverter, a shareware Mac OS X image viewer (primarily) and editor
• Adobe Photoshop, a Windows and Mac OS X image editor

[edit] Repair

Removing the first four bytes fixes the files, as expected, enabling any JPEG viewer or editor to handle them. This doesn't take much work, but cannot generally be (easily) accomplished with built-in tools of Windows and Mac OS X. However, there are two fan-developed programs that will fix the bug:

[edit] KI Image Fixer

KI Image Fixer is an application for Mac OS X and Windows which specifically aims to fix such files. By pointing it at JPEG images, it will determine whether their format appears to be correct; if they suffer the aforementioned bug, it will correct the images, and optionally create a backup. This program was developed by Chucker.

It can be downloaded for free from the MYSTlore project page at Google Code, and requires no installation.

[edit] Uru Live Jpeg Fixer

Uru Live Jpeg Fixer is an application for Windows only, and which also specifically fixes KI images. This program was developed by AdamJohnso.

It can be downloaded for free from this thread at UruObsession.

[edit] Unix Command-Line Fix

On any Unix system (including Mac OS X), you can type the following shell command:

tail -c +5 ORIGINAL.jpg > FIXED.jpg

Substitute in the name of the original file, and a name to store the new file as. (Don't repeat the original name! Pick a new one.)

[edit] Caveat

Do not "fix" the image files that are found in the Avatars folder. The Uru client requires those four extra bytes to be there. If you replace the thumbnail JPG file with a fixed version, the Uru client will try to read it, fail, and crash. (Or suffer some other unpleasant fate.) If you want a fixed version of the thumbnail, make a copy in your own directory and fix that one.

[edit] Status

Responses from Cyan regarding this issue have been sparse as well as contradictory. One support ticket was closed with the assertion that the behavior is "as expected", whereas most other responses have been to the effect that it's a "known issue". In either case, no comment has been made on whether or when a fix is to come.

[edit] Deliberate?

Some speculate that this measure is a deliberate attempt to prevent abuse. However, not only is there little potential for abuse to begin with – one cannot re-upload the edited image back to the Uru Live servers; it's also a very weak security measure, if any at all, doing virtually nothing to mitigate (let alone prevent) any kinds of abuse.

[edit] Done for Photo on Selection Screen?

I had it explained to me, that it was a fix to get the avatar selection screen photo working. When you are in your closet, in the head edit area, there is a 'camera' symbol. By clicking this symbol you put a head shot of your character on your selection screen. There was a problem with it not working at first, which was fixed by adding a 4 byte length in front of the photo. It was later found that the closet photo shot, and the KI images used the same code. So when they added the 4 bytes to the photo, they also added the 4 bytes to the KI images. The fix of the photo then broke the viewing of the KI images.