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NiLuJe · 06-24-2013, 11:20 PM

@PoP: IIRC (it's been a while), provided the ASIN is valid (ie. not a Calibre UUID), and the metadata pointer to the thumbnail is correct (both Calibre & Kindlegen handle that properly, provided you have a decent cover, AFAIR), the Kindle should build & cache a thumbnail from the book itself.

(I think fred_be9300 managed to dig up most of my better answer on this very subject from the Calibre forum

).

Where it can get tricky is that there a weird bit of caching involved, and if you 'trick' the Kindle by *replacing* the file from outside of the OS (ie. over USB/SSH), all hell breaks lose and the catalog gives up on the thumbnail, even (or especially, can't remember) if you supplied a thumbnail jpg yourself.

So: delete the file *from the Kindle itself*, then upload a new version. (AFAICT, what you did seems correct, I'll take a look at it with KindleUnpack, though).

I mostly work with KF8 files, so there might be an extra weird step for KF7 files...

EDIT: Ah, yes, now I remember. There is indeed a bit of trickery involved depending on the format.

KF8: It doesn't build the thumbnail from the book, it downloads it from Amazon's servers (thus the requirement on a valid ASIN). If, like Calibre, we sideload the thumbnail ourself, we don't care about the valid ASIN requirement, it works fine with a Calibre UUID.

KF7: It does build it from the book, and yours is properly setup, metadata-wise.

So, err, I guess with a combo file, since those devices are KF8 aware, it defaults to the annoying KF8 download thing, which is why we sideload the thumb ourself in Calibre.

My warning about the weird caching of the cataloger still applies, though, since I definitely remember it biting me on the ass during my initial Calibre tests

.

As for the PDOC banner/cdeType, I don't *think* it has any other impact on all this, although, again, I do most of my tests with EBOK cdeType, not PDOCs

.

EDIT²: If this post doesn't make any kind of sense, it's on me. I've been staring at my backlog of posts for a few hours now (wee! 3 months and a half left! xD), and I'm calling it a night (well, an early day, I guess, since it's now nearly 6AM, *sigh*).

EDIT^3: Wait, actually, it does have an effect. I think KF8 PDOCs also fall back to the built-in thumbnail, but you have to live with the personal doc banner.

06-24-2013, 11:20 PM	#65
NiLuJe BLAM! Posts: 13,506 Karma: 26047202 Join Date: Jun 2010 Location: Paris, France Device: Kindle 2i, 3g, 4, 5w, PW, PW2, PW5; Kobo H2O, Forma, Elipsa, Sage, C2E	@PoP: IIRC (it's been a while), provided the ASIN is valid (ie. not a Calibre UUID), and the metadata pointer to the thumbnail is correct (both Calibre & Kindlegen handle that properly, provided you have a decent cover, AFAIR), the Kindle should build & cache a thumbnail from the book itself. (I think fred_be9300 managed to dig up most of my better answer on this very subject from the Calibre forum ). Where it can get tricky is that there a weird bit of caching involved, and if you 'trick' the Kindle by replacing the file from outside of the OS (ie. over USB/SSH), all hell breaks lose and the catalog gives up on the thumbnail, even (or especially, can't remember) if you supplied a thumbnail jpg yourself. So: delete the file from the Kindle itself, then upload a new version. (AFAICT, what you did seems correct, I'll take a look at it with KindleUnpack, though). I mostly work with KF8 files, so there might be an extra weird step for KF7 files... EDIT: Ah, yes, now I remember. There is indeed a bit of trickery involved depending on the format. KF8: It doesn't build the thumbnail from the book, it downloads it from Amazon's servers (thus the requirement on a valid ASIN). If, like Calibre, we sideload the thumbnail ourself, we don't care about the valid ASIN requirement, it works fine with a Calibre UUID. KF7: It does build it from the book, and yours is properly setup, metadata-wise. So, err, I guess with a combo file, since those devices are KF8 aware, it defaults to the annoying KF8 download thing, which is why we sideload the thumb ourself in Calibre. My warning about the weird caching of the cataloger still applies, though, since I definitely remember it biting me on the ass during my initial Calibre tests . As for the PDOC banner/cdeType, I don't think it has any other impact on all this, although, again, I do most of my tests with EBOK cdeType, not PDOCs . EDIT²: If this post doesn't make any kind of sense, it's on me. I've been staring at my backlog of posts for a few hours now (wee! 3 months and a half left! xD), and I'm calling it a night (well, an early day, I guess, since it's now nearly 6AM, sigh). EDIT^3: Wait, actually, it does have an effect. I think KF8 PDOCs also fall back to the built-in thumbnail, but you have to live with the personal doc banner. Last edited by NiLuJe; 06-25-2013 at 01:40 AM.