Kindle Touch Custom Screensavers

[sparrowlight]

Hello, yifanlu -- any idea when this will be updated to be compatible with 5.1? Thanks!

[Selrond]

5.1.2 and still doesn`t work... is there any other option how to use custom screensavers?
(ad-hacked, jailbroken touch)

[ixtab]

Learn to read. It is clearly documented in the Wiki that only the "simple" method works on newer firmware versions. Heck, I even posted a link directly to the relevant subsection of the Wiki, when answering to your cross-post in the jailbreak thread.

[dukesilver]

Is it possible to hack it so that it will auto display the book cover image of the one you're currently reading?

[sparrowlight]

Originally Posted by dukesilver

Is it possible to hack it so that it will auto display the book cover image of the one you're currently reading?

Not currently, no. I try to keep on top of the latest hacks/mods and I haven't seen anything that will do this. It's a pretty common request though.

[ixtab]

Originally Posted by sparrowlight

Not currently, no. I try to keep on top of the latest hacks/mods and I haven't seen anything that will do this. It's a pretty common request though.

And I guess it won't happen. Even though it's technically possible, the covers would look horrible, because they are in a much smaller resolution than the 600x800 that the screen provides.

[sparrowlight]

Oh, I don't personally want it! And I've always got a bunch of books that I'm currently reading, so it would be largely irrelevant. I'm happy making my own screensavers with art or other images.

[dukesilver]

Originally Posted by ixtab

And I guess it won't happen. Even though it's technically possible, the covers would look horrible, because they are in a much smaller resolution than the 600x800 that the screen provides.

Is there not a way to extract the larger image from the book file itself? Do the sony e-readers that display the book cover require each book to include a separate larger image for the screensaver?

[ixtab]

Originally Posted by dukesilver

Is there not a way to extract the larger image from the book file itself? Do the sony e-readers that display the book cover require each book to include a separate larger image for the screensaver?

I don't know... I'm not terribly familiar with the file formats. All I know is that the files which get extracted (into system/thumbnails or so, IIRC) are very low resolution. It *might* be the case that the books themselves actually contain a larger image, and that they're already scaled down during extraction - or even that they contain a large image and a thumbnail. Dunno. Someone would have to take a closer look at it.

[NiLuJe]

@ixtab: There is a proper 'cover' in most mobi files, yes (Go To > Cover to see it, exth 201 should be a pointer to it in the mobi header), but your point still stands. It's very, very rarely exactly 600x800, and usually a color JPG, not a grayscale PNG.

[dukesilver]

even if the image embedded in the mobi doesn't look that great because it's not exactly the right size or because it's a color JPG I wouldn't mind. as long as the screensaver displayed something passable as the current book cover, I would be satisfied. but maybe I'm in the minority in that thinking.

[NiLuJe]

@dukesilver: It's not the user I'm worried about, it's the backend blowing up if the files don't match the exact expected parameters . (meaning it would need a lot of massaging/sanitizing, and that's after: being able to catch the current/last opened book, being able to inject a new screensaver without restarting the framework, being able to tell the framework we only want to see *this* specific screensaver, being able to extract the cover from the mobi, being able to hook all that into a proper event at all, and more specifically, without it being a battery drain).

TL;DR: Have fun!

[Akirainblack]

It doesn't matter if it's greyscale or not in my experience with my Touch.
I've been testing and as long as it's a PNG it doesn't matter.
If any dimension <800x600 you get some of the text displayed behind it.
If any dimension >800x600 it crops the image.
If it's colour it's still displayed happily (obviously in greyscale).
This is ofc using the simple screensaver hack.

[someone]

First of all, thank you Yifanlu for this amazing hack that lets you display the current page on the lock screen. I actually think this is how the device *should* work. So much so that I am reluctant to buy a new Kindle if I can't have this feature. Does anyone know if this is possible on the new e-ink models like Kindle 2024 or Kindle Paperwhite 2024?

Originally Posted by yifanlu

Well, in short, the old "simple screensaver" hack I wrote a while ago sucks. This is a REAL screensaver hack.


This Kindle Touch modification will allow you to use custom images as screensavers. This is not for Special Offer Kindles, nor does it remove the advertisements. By design, this mod will only work with non-ads Kindle Touches. An improvement of this vs the screensaver hacks of previous devices and the simple screensaver hack I released a while ago includes:

• No filename constraint (name the images anything you want)
• Auto update when new files are found
• Scrolls through in alphabetical order (not random order, so you can manage the order of the images)
• If no custom images are found, it will default back to Kindle’s original screensavers
• If an invalid file is found, it will be skipped, after 5 invalid files, it will default back to original screensaver (instead of just crashing and requiring a restart)

In addition, images are auto-scaled and auto-converted, which means you are no longer limited to 600×800 grayscale images. Of course, those are the preferred format, but you can now use any PNG file and it will be sized to fit the screen. The only limitation is the image format must be PNG.

Finally, as an added bonus, I’ve included a custom screensaver, “lockscreen.png”. If you place that image in your screensaver folder (and nothing else), instead of a picture screensaver, the Kindle will keep whatever you are reading as the screensaver with a neat lock icon on the top of the screen. (See end of post for example)

As always, installation and usage directions are found in the readme after download.

All this is made possible by OpenBlanket, my attempt at reversing the APIs for LibBlanket, Amazon’s library for drawing full screen content on the Kindle Touch. You can check out the source for an almost identical re-implementation of the device’s original screensaver module (decompiled by hand and compiles to almost the exact same machine code). The source for the custom screensaver module is a modification of that source (and is included in the download).

Download: http://yifan.lu/p/custom-screensaver/
OpenBlanket: https://github.com/yifanlu/OpenBlanket




My stance on removing ads: I've posted my opinions about this in many threads, but not everybody has read it. First of all, I will never stop anyone from removing ads. It's very easy to do, and there are many ways of doing it. However, I will never aid anyone in doing so, so please don't ask me for help. The reason is that our main defense for jailbreaking the device being legal and ethical is that "we aren't doing anything to hurt amazon." Now I understand Amazon is a big corporation (as with all big corporations, they are amoral, hence, they can be evil). However, when you remove the ads without paying Amazon $40, they lose money, which means that if enough people start removing ads to make an impact they could take action against people like me who bring you the ability to unlock your devices. Since technically, the TOS for the Kindle states that you cannot modify or reverse engineer the device. No, Amazon is not enforcing it. No, I do not agree with it. But Amazon has always been passive in stopping jailbreaks (removing the exploit but not touching the hacks; not worrying about people who jailbreak; allowing people with jailbroken devices to have support even though you technically broke the TOS and can be denied support), but if they start losing money they could start actively blocking jailbreaks.