Dual MOBI cover problems

AppleTard · 08-25-2015, 11:00 PM

Hi,

I've recently decided to to convert my books to dual mobi format because it's inherently better than the old MOBI, and Amazon doesn't allow you to send pure azw3 files through its "Send to Kindle" app. And this part is important: I highly value Amazon's cloud for storing my books, since it keeps everything synched between my devices.

My primary ebook reader is the Kindle Voyage. When I Mobi files using the old format, the cover shows up just fine. However, if I send it as a dual Mobi, there's no cover thumbnail on the "cover view."

Am I doing anything wrong, or is this the expected behavior? I know the cover image is in the book - if I flip back the pages, I can see it. The problem is restricted to the thumbnail image.

It's not a big deal, though - I can always switch to list view. I just want to know whether I'm the one causing the issue, or if anything can be done about it.

Thanks in advance.

odamizu · 08-25-2015, 11:20 PM

I'm not positive, but I think this is the expected behavior, and it's what's happening for me.

I've been experimenting with the "Fix ASIN for KindleFire" command in the Quality Check plug-in", which will cause a Kindle to download covers for AZW3, but it doesn't seem to work for AZW3s inside dual-MOBIs.

eschwartz · 08-26-2015, 12:16 AM

That is a bug in Amazon's Personal Documents service. In order to understand what is going on, you will first have to understand a bit more about covers.

For books you download from Amazon (or actually anything that has an ASIN), the Kindle will ignore the cover inside the book, and attempt to download the cover from Amazon's server (using the ASIN to identify the correct book to retrieve a cover for).
For sideloaded books, assuming you do not use calibre or Java Mobi Metadata Editor to embed an ASIN, the cover is extracted from the ebook file.

All this is irrespective of whether or not there is an actual, honest-to-goodness cover embedded in the book.

If you sideload with calibre, caliibre will notice that the book has an ASIN, and sideload a cover to go with the book -- this is very useful when the ASIN is a fake one generated by calibre's conversion

because otherwise you would have *no* cover.

Why does this matter? Because a book that has gone through the Personal Documents service has an ASIN -- the one that links it to your cloud account.
The cover will not be extracted from the book.

And there is apparently a bug in the service, that prevents it sending covers for an AZW3 (but a MOBI works fine).

@quiris has written a cross-platform application that will extract the cover from the *.azw3 and generate a cover thuumbnail, see post #14 of this thread: https://www.mobileread.com/forums/sho...d.php?t=212242

odamizu · 08-27-2015, 10:58 PM

Thanks for the clarification, eschwartz! As much as I like my Kindle, the way Amazon handles covers is frustrating :/

EbokJunkie · 08-28-2015, 06:49 PM

@odamizu
This Python script completes extraction of cover (broken in Kindle software) from azw3 book downloaded to your PW or Voyage. Just run it in command line directly over the downloaded azw3 file (in Documents folder) with key -cl and key value yes (-cl yes).

odamizu · 08-28-2015, 07:53 PM

Thanks! I will look into it.

AppleTard · 08-29-2015, 03:29 PM

Thanks for the in-depth explanation, eschwartz. I'll just switch to list view and don't worry about covers anymore. Maybe Amazon will fix it eventually.

eschwartz · 08-30-2015, 01:00 AM

If list view is fine with you, then sure.

If you are attached to your covers, or just think it is worth it to run a simple app which fixes everything, then use quiris' app which I linked to above -- which to save you added link-following (since I linked the discussion, which links to the app, maybe that was too indirect

) is here: https://github.com/quiris11/ExtractCoverThumbs/releases

@odamizu, don't use the program @EbokJunkie linked to, it is far newer, appears to do something totally different that merely coincidentally fixes covers, and requires you to run again and again for every file you want to fix.
Also, I know quiris' app sizes images properly for the larger-resolution E-Ink devices, and goes above and beyond the call of duty by shifting thumbnails up to account for the "Personal" banner.

odamizu · 08-30-2015, 01:32 PM

Quiris's app is fabulous! Thanks again, eschwartz, for the pointer. Unexpected bonus: apnx file for page numbers.

Do you happen to know how the page numbers are calculated? Just curious, and the GitHub explanation went over my head.

eschwartz · 08-30-2015, 02:13 PM

The page numbers are inspired from calibre's more complete offering.

AFAIK, you would need to create a CSV containing mappings between the book ASIN and the correct page count, or else it just uses calibe's original "fast" method.

odamizu · 08-30-2015, 05:52 PM

Thanks! Calibre's "fast" method is good enough for me

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08-25-2015, 11:00 PM	#1
AppleTard Member Posts: 24 Karma: 1839286 Join Date: Nov 2010 Device: iPad	Dual MOBI cover problems Hi, I've recently decided to to convert my books to dual mobi format because it's inherently better than the old MOBI, and Amazon doesn't allow you to send pure azw3 files through its "Send to Kindle" app. And this part is important: I highly value Amazon's cloud for storing my books, since it keeps everything synched between my devices. My primary ebook reader is the Kindle Voyage. When I Mobi files using the old format, the cover shows up just fine. However, if I send it as a dual Mobi, there's no cover thumbnail on the "cover view." Am I doing anything wrong, or is this the expected behavior? I know the cover image is in the book - if I flip back the pages, I can see it. The problem is restricted to the thumbnail image. It's not a big deal, though - I can always switch to list view. I just want to know whether I'm the one causing the issue, or if anything can be done about it. Thanks in advance.

08-25-2015, 11:20 PM	#2
odamizu just an egg Posts: 1,586 Karma: 4300000 Join Date: Mar 2015 Device: Kindle, iOS	I'm not positive, but I think this is the expected behavior, and it's what's happening for me. I've been experimenting with the "Fix ASIN for KindleFire" command in the Quality Check plug-in", which will cause a Kindle to download covers for AZW3, but it doesn't seem to work for AZW3s inside dual-MOBIs.

08-26-2015, 12:16 AM	#3
eschwartz Ex-Helpdesk Junkie Posts: 19,422 Karma: 85397180 Join Date: Nov 2012 Location: The Beaten Path, USA, Roundworld, This Side of Infinity Device: Kindle Touch fw5.3.7 (Wifi only)	That is a bug in Amazon's Personal Documents service. In order to understand what is going on, you will first have to understand a bit more about covers. For books you download from Amazon (or actually anything that has an ASIN), the Kindle will ignore the cover inside the book, and attempt to download the cover from Amazon's server (using the ASIN to identify the correct book to retrieve a cover for). For sideloaded books, assuming you do not use calibre or Java Mobi Metadata Editor to embed an ASIN, the cover is extracted from the ebook file. All this is irrespective of whether or not there is an actual, honest-to-goodness cover embedded in the book. If you sideload with calibre, caliibre will notice that the book has an ASIN, and sideload a cover to go with the book -- this is very useful when the ASIN is a fake one generated by calibre's conversion because otherwise you would have no cover. Why does this matter? Because a book that has gone through the Personal Documents service has an ASIN -- the one that links it to your cloud account. The cover will not be extracted from the book. And there is apparently a bug in the service, that prevents it sending covers for an AZW3 (but a MOBI works fine). @quiris has written a cross-platform application that will extract the cover from the *.azw3 and generate a cover thuumbnail, see post #14 of this thread: https://www.mobileread.com/forums/sho...d.php?t=212242

08-27-2015, 10:58 PM	#4
odamizu just an egg Posts: 1,586 Karma: 4300000 Join Date: Mar 2015 Device: Kindle, iOS	Thanks for the clarification, eschwartz! As much as I like my Kindle, the way Amazon handles covers is frustrating :/

08-28-2015, 06:49 PM	#5
EbokJunkie Addict Posts: 229 Karma: 13495 Join Date: Feb 2009 Location: SoCal Device: Kindle 3, Kindle PW, Pocketbook 301+, Pocketbook Touch, Sony 950, 350	@odamizu This Python script completes extraction of cover (broken in Kindle software) from azw3 book downloaded to your PW or Voyage. Just run it in command line directly over the downloaded azw3 file (in Documents folder) with key -cl and key value yes (-cl yes).

08-28-2015, 07:53 PM	#6
odamizu just an egg Posts: 1,586 Karma: 4300000 Join Date: Mar 2015 Device: Kindle, iOS	Thanks! I will look into it.

08-29-2015, 03:29 PM	#7
AppleTard Member Posts: 24 Karma: 1839286 Join Date: Nov 2010 Device: iPad	Thanks for the in-depth explanation, eschwartz. I'll just switch to list view and don't worry about covers anymore. Maybe Amazon will fix it eventually.

08-30-2015, 01:00 AM	#8
eschwartz Ex-Helpdesk Junkie Posts: 19,422 Karma: 85397180 Join Date: Nov 2012 Location: The Beaten Path, USA, Roundworld, This Side of Infinity Device: Kindle Touch fw5.3.7 (Wifi only)	If list view is fine with you, then sure. If you are attached to your covers, or just think it is worth it to run a simple app which fixes everything, then use quiris' app which I linked to above -- which to save you added link-following (since I linked the discussion, which links to the app, maybe that was too indirect ) is here: https://github.com/quiris11/ExtractCoverThumbs/releases @odamizu, don't use the program @EbokJunkie linked to, it is far newer, appears to do something totally different that merely coincidentally fixes covers, and requires you to run again and again for every file you want to fix. Also, I know quiris' app sizes images properly for the larger-resolution E-Ink devices, and goes above and beyond the call of duty by shifting thumbnails up to account for the "Personal" banner.

08-30-2015, 01:32 PM	#9
odamizu just an egg Posts: 1,586 Karma: 4300000 Join Date: Mar 2015 Device: Kindle, iOS	Quiris's app is fabulous! Thanks again, eschwartz, for the pointer. Unexpected bonus: apnx file for page numbers. Do you happen to know how the page numbers are calculated? Just curious, and the GitHub explanation went over my head.

08-30-2015, 02:13 PM	#10
eschwartz Ex-Helpdesk Junkie Posts: 19,422 Karma: 85397180 Join Date: Nov 2012 Location: The Beaten Path, USA, Roundworld, This Side of Infinity Device: Kindle Touch fw5.3.7 (Wifi only)	The page numbers are inspired from calibre's more complete offering. AFAIK, you would need to create a CSV containing mappings between the book ASIN and the correct page count, or else it just uses calibe's original "fast" method.

08-30-2015, 05:52 PM	#11
odamizu just an egg Posts: 1,586 Karma: 4300000 Join Date: Mar 2015 Device: Kindle, iOS	Thanks! Calibre's "fast" method is good enough for me