ebook cover lockscreen doesn't work for sideloaded books

[odamizu]

Originally Posted by PeterCay

There must be a way to show custom book covers as a lockscreen without a proper Amazon ASIN number.

As an example I have the mobi book of "The Swiss Family Robinson" by J.D. Wyss

mobi-asin:340ffd6b-ba15-4894-b570-a07b846f00f5

My kindle can show the custom Hungarian language cover of this book as lockscreen. It is definitely not sold by amazon, only in English language with a completely different cover.

Other books with the same mobi-asin format is not showing their covers as lockscreen (showing only in the library of course).

What I don't understand is, how to read these mobi-asin codes, and therefore, how to set a proper one or a proper fake one for them.

If your Kindle is showing a cover for a book Amazon does not sell, then forget everything I've written. As I said, this info is from when I was messing with covers years ago, before I started using Send to Kindle, and it may not be accurate now. Also, I was doing this to get covers in cover view and have no idea if the new screensaver feature works the same way.

But to provide more info on how it worked in the past:

If an azw3 has a proper ASIN, Kindle thinks it comes from Amazon and will download the cover from Amazon's server (you need to be connected to WiFi, obviously). Once downloaded, you can disconnect from WiFi if you want.

For a proper ASIN, the ebook needs to have 3 tags properly configured: EXTH 113, EXTH 504, EXTH 501. This is hidden file format metadata, which is not the same as the book metadata.

If you input the ASIN in the opf, Calibre's Quality Check plugin, will take the ASIN found in the opf and fix the EXTH tags. Sigil's KindleGen plugin will do the same if you check "Add fake ASIN".

Take all this with a grain of salt as my memory on all this may be faulty.

[alex1798]

I download epubs, they already come with covers.

In Calibre, if I don´t like a cover, I change it and use a jpg the size of my kindle PW (1448 × 1072 pixels) or leave the original cover they already come with (800x600).

After, I run the polish books function, with the update metadata and update cover options on.

I convert them to azw3, and transfer them to my Kindle PW4.

Disconnect kindle, then reconnect to PC with kindle open (so the kindle doesn't change covers), and disconnect again.

I've doing that to all my books since before anyway, and now they show fine with the cover on the kindle. 800*600 looks ok on the kindle (with black bar at the sides), but 1448*1072 looks better ofc.

I don´t have to mess with asin, isbn or anything, since my epubs don't come with that.

*just one time I had a problem with one ebook not showing the cover, so I deleted it, changed the cover with calibre, did the steps above, reseted the kindle, and it worked.

That's my two cents.

[RetroEggy]

Since having the book cover as lockscreen was a feature I've been wishing for for quite a while now, I was very eager to try it out when I first heard about it being introduced to kindle devices.
After fiddling around for a while and consulting this thread, I can add the following experiences I've made:

For me, this only worked when using azw3 format. I had to convert my books and then send them directly via usb through Calibre.

Using mobi didn't get me the cover as lockscreen in any way, even when using the same books that worked fine as azw3 just before (as a result, sending books to my kindle via email now is out of the question since that doesn't accept azw3 files).
The ASIN, at least in my experience, has nothing to do with the cover being used as lockscreen - I transferred two azw3 books, on with and one without ASIN and both worked fine. From what I can tell, the ASIN only seems to be necessary for having the cover in the gallery view and only if one transferred the files manually via file explorer, not via calibre.

If the cover doesn't show up in gallery view, it is necessary to refresh the kindle's metadata cache - either through rebooting or via Calibre when a kindle is connected: Device->refresh metadata cache (the options might be named differently since I translated this from the german Calibre GUI)

Hope this helps others that are struggling with using this feature with sideloaded books!

[RetroEggy]

A small addition to my last post: Sometimes, it is necessary to flip a few pages for the cover lockscreen to work. Also, I found one book that still doesn't work even after using azw3. Maybe something went wrong when sending it to the kindle. All other books that work correctly start on the book's first page, but this "defective" book has the cover as the first page when opened on the kindle. Let's hope amazon simplifies this in the future (I know, I know, why would they, but hey, don't lose hope).

[Dr. Drib]

I can see that it works perfectly on side-loaded ebooks not purchased from Amazon. I have this title on my Kindle Oasis so I can check it out for any inconsistencies or errors as I proofread. The temp cover is viewable on the right of the image. This is the cover that's viewable when I open my Oasis.

I know this because the writing has yet to be completed and is not yet available anywhere!

[jhowell]

I plan to research what characteristics a book needs for the cover to show once I have this feature on my Oasis. For now I just took a quick look at some of the Kindle software related to the cover view.

It appears that it can be blocked by various criteria. It looks like it won't work for Audible books, dictionaries, or newspapers. Books in PDF or Topaz format also will not work. The book needs to have both CDEContentType (EXTH 501) and CDEContentKey (EXTH 504) metadata set. It looks like the cover dimensions may need to fall within a certain range, but I don't know exactly what.

Books produced using Amazon's kindlegen or Kindle Previewer will lack the metadata needed for cover display if sideloaded via USB. Calibre will also omit this metadata if the "Enable sharing of book content" conversion option is selected.

[Badcatalex]

I load third-party e books via Calibre and have no issues. Maybe it's because the covers are too low res?