KFX Format - Page 22

AaronShep · 12-20-2015, 11:57 AM

Quote:

Originally Posted by jhowell

Aaron, it sounds like you have made contact with someone knowledgeable about KFX at Amazon.

Did you discover whether these problems need to be fixed in the central KFX generation process or individual reading devices or both?

I'm afraid there's a limit to what I can say for now, and there's much more that I don't know. But I think it has already become clear that changes can happen at any time, so at least some of these must be made in the processing. KFX is definitely a work in progress and likely always will be.

jhowell · 12-25-2015, 07:28 PM

Quote:

Originally Posted by AaronShep

I'm afraid there's a limit to what I can say for now, ...

I noticed that in your book HTML Fixes for Kindle you use white-space: nowrap and that it seems to be effective even in the KFX version of the book. Hopefully you will be able to share other useful tidbits in the future.

AaronShep · 12-26-2015, 02:28 AM

Quote:

Originally Posted by jhowell

I noticed that in your book HTML Fixes for Kindle you use white-space: nowrap and that it seems to be effective even in the KFX version of the book. Hopefully you will be able to share other useful tidbits in the future.

It does work, and I recommend it in place of the nonbreaking hyphen, which causes problems on some Kindles. But you shouldn't need it in place of the nonbreaking space if KFX recognizes that in the form of an HTML entity, or if the Kindle team fixes the problem with the nonbreaking space character being ignored -- which is what I hope.

jhowell · 02-08-2016, 02:02 PM

I downloaded the new Kindle Previewer 3 (Beta), which adds support for Enhanced Typesetting (KFX).

The list of file types it opens are: .kpf, .mobi, .azw, .epub, .htm, .html, .xhtml, .opf, .prc, .azw3, and .azw8. (azw8 is an alternate extension for kfx.)

There are some interesting file names in the previewer software. For example:
Kindle Previewer 3\lib\fc\lib\EpubToKFXConverter-1.0.jar

So it looks like there may be a way to convert our own books to KFX using this software. I am sure that there is a lot to be learned from it.

ETA: Kindle Package Format (.kpf) is the format produced by Kindle Textbook Creator.

Doitsu · 02-10-2016, 08:30 AM

Quote:

Originally Posted by jhowell

I downloaded the new Kindle Previewer 3 (Beta), which adds support for Enhanced Typesetting (KFX).

I had a quick look at it, too. The preview, which is currently limited to Kindle Fire and Kindle for iOS, appears to working, but it won't generate .kfx files for sideloading.

Quote:

Originally Posted by jhowell

There are some interesting file names in the previewer software. For example:
Kindle Previewer 3\lib\fc\lib\EpubToKFXConverter-1.0.jar

There are also interesting files in:

Code:

%USERPROFILE%\AppData\Local\Amazon\Kindle Previewer 3\lib\fc\bin

For example, MobiContentDumper.exe dumps the mobi7 and mobi8 parts of KindleGen generated .mobi files as .json files.

The usage is:

Code:

mobicontentdumper dump_mobi7|dump_mobi8 [-outdir=XXX]

Hopefully, this tool will eventually allow the KindleUnpack developers to reverse-engineer the KFX format.

Another interesting file is yjhtmlcleanerapp. The usage is:

Code:

yjhtmlcleanerapp inputJsonFile
yjhtmlcleanerapp inputHTMLFile outputHTMLFile

jhowell · 02-12-2016, 02:01 PM

Amazon is continuing to expand their use of KFX. I just downloaded a graphic novel using the latest version of the Android app and I noticed that, even though the Amazon web page for it shows "Enhanced Typesetting: Not Enabled", the book downloaded to the device as a series of KFX files.

AaronShep · 02-13-2016, 12:13 AM

Quote:

Originally Posted by Doitsu

Another interesting file is yjhtmlcleanerapp. The usage is:

Code:

yjhtmlcleanerapp inputJsonFile
yjhtmlcleanerapp inputHTMLFile outputHTMLFile

This supports a new theory of mine that processing for KFX/Enhanced Typesetting doesn't so much add anything as just remove or clean up any code that would get in the way. Then it signals the Kindle to use a different rendering engine.

jhowell · 02-15-2016, 11:17 PM

Quote:

Originally Posted by Doitsu

I had a quick look at it, too. The preview, which is currently limited to Kindle Fire and Kindle for iOS, appears to working, but it won't generate .kfx files for sideloading.

The previewer produces a new file type, KDF, which is basically KFX data in an sqlite3 database instead of a KFX container. I wonder if that is something specific to the previewer software or if this is an intermediate format produced as part of their production tool chain. I'm learning quite a bit from examining these files.

baf · 02-16-2016, 09:23 AM

I also played with some temporary files created during conversion. That gives an idea about optimization process.
For example have a look at changes introduced to the original xhtml file, while converting epub to enhanced mobi.

UPDATE: The link expired, so I am posting the files here

pdurrant · 02-16-2016, 09:30 AM

Quote:

Originally Posted by baf

For example have a look at changes introduced to the original xhtml file, while converting epub to enhanced mobi.

Which is which?

baf · 02-16-2016, 09:33 AM

Quote:

Originally Posted by pdurrant

Which is which?

Original file from epub on the left

KevinH · 02-16-2016, 09:36 AM

Wow! - what a mess it makes! Every element seems to have height and width attribute. They also remove the link to external css. It looks like they are making some sort fixed layout epub.

You can actually find the javascripts they use to make these adjustments in the Kindle Previewer 3 app as well.

I simply can not get Previewer to actually make a kfx (or kfd) file of any kind no matter which device I pick. Any hints on how to invoke it to see it actually it make a kfx file from an azw3?

KevinH

Quote:

Originally Posted by baf

I also played with some temporary files created during conversion. That gives an idea about optimization process.
For example have a look at changes introduced to the original xhtml file, while converting epub to enhanced mobi.

KevinH · 02-16-2016, 09:39 AM

baf, can you get a dump of the environment variables that are set during the conversion to kfx? The internal Epub conversion jar seems to look for AMZN_ prefixed environment variables in places but so it might help to see what is getting set.

KevinH

pdurrant · 02-16-2016, 09:41 AM

I suspect that all those hard coded values in the HTML will change depending on the destination device. If so, the KFX format must be intended to move the processing of complex CSS layouts to Amazon's servers rather than the ebook reader processor, leaving much more straightforward HTML for the ebook reader to set.

HarryT · 02-16-2016, 09:46 AM

Quote:

Originally Posted by pdurrant

I suspect that all those hard coded values in the HTML will change depending on the destination device. If so, the KFX format must be intended to move the processing of complex CSS layouts to Amazon's servers rather than the ebook reader processor, leaving much more straightforward HTML for the ebook reader to set.

We did know that one of the goals of the KFX format was to supply device-specific formatting - eg image resolutions tailored to the device.

02-08-2016, 02:02 PM	#319
jhowell Grand Sorcerer Posts: 7,087 Karma: 91577715 Join Date: Nov 2011 Location: Charlottesville, VA Device: Kindles	I downloaded the new Kindle Previewer 3 (Beta), which adds support for Enhanced Typesetting (KFX). The list of file types it opens are: .kpf, .mobi, .azw, .epub, .htm, .html, .xhtml, .opf, .prc, .azw3, and .azw8. (azw8 is an alternate extension for kfx.) There are some interesting file names in the previewer software. For example: Kindle Previewer 3\lib\fc\lib\EpubToKFXConverter-1.0.jar So it looks like there may be a way to convert our own books to KFX using this software. I am sure that there is a lot to be learned from it. ETA: Kindle Package Format (.kpf) is the format produced by Kindle Textbook Creator. Last edited by jhowell; 02-08-2016 at 04:58 PM.

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02-12-2016, 02:01 PM	#321
jhowell Grand Sorcerer Posts: 7,087 Karma: 91577715 Join Date: Nov 2011 Location: Charlottesville, VA Device: Kindles	Amazon is continuing to expand their use of KFX. I just downloaded a graphic novel using the latest version of the Android app and I noticed that, even though the Amazon web page for it shows "Enhanced Typesetting: Not Enabled", the book downloaded to the device as a series of KFX files.

02-16-2016, 09:39 AM	#328
KevinH Sigil Developer Posts: 8,808 Karma: 6000000 Join Date: Nov 2009 Device: many	baf, can you get a dump of the environment variables that are set during the conversion to kfx? The internal Epub conversion jar seems to look for AMZN_ prefixed environment variables in places but so it might help to see what is getting set. KevinH

02-16-2016, 09:41 AM	#329
pdurrant The Grand Mouse 高貴的老鼠 Posts: 74,015 Karma: 315160596 Join Date: Jul 2007 Location: Norfolk, England Device: Kindle Oasis	I suspect that all those hard coded values in the HTML will change depending on the destination device. If so, the KFX format must be intended to move the processing of complex CSS layouts to Amazon's servers rather than the ebook reader processor, leaving much more straightforward HTML for the ebook reader to set.