Kindle for Mac1.25.2 with the new kindle format--.kcr?

Iris-maybe · 03-07-2019, 03:16 AM

Kindle for Mac 1.25.2 is available now. No. kfx format, but .KCR. Any idea of this change?

HarryT · 03-07-2019, 04:22 AM

Moved to the Kindle forum.

jhowell · 03-07-2019, 10:03 AM

I saw signs that KCR support was added to Kindle for PC/Mac, but this is the first I have heard of it being used. KCR is the format used by Kindle Cloud Reader, the browser-based reading app. It is also used by the Kindle for iOS app in place of KF8 (azw3). Perhaps for some reason Amazon is dropping KF8 on the Mac platform as they did on iOS.

I would like to know more.

What is the build number of K4Mac you are using? This is the number in parenthesis after the main version number. As far as I know build 52077 is the latest downloadable version and build 52078 is the version available from the Mac app store.

Can you give an example of a book that is showing in KCR format for you?

Are you in the US and using amazon.com are you in another country?

odamizu · 03-08-2019, 01:36 PM

I just downloaded K4Mac and it's still 52077. I'm in the US using amazon.com. I haven't installed it though and don't plan to given the KFX problem.

I thought iOS uses AZK. Or is AZK an older iOS format that's being replaced by KCR?

jhowell · 03-08-2019, 02:07 PM

Quote:

Originally Posted by odamizu

I thought iOS uses AZK. Or is AZK an older iOS format that's being replaced by KCR?

AZK and KCR are basically the same thing. Both contain "fragments" of HTML code to be rendered using a web browser or a native HTML rending engine. The main difference is that KCR is delivered by Amazon and has DRM while AZK is created by users and is meant to be side loaded.

It is supposed that the Kindle for iOS app was forced to use AZK/KCR format instead of KF8 (azw3) because of Apple's rule preventing iOS apps from containing their own HTML rendering engines. (KF8 is based on an outdated version of webkit.)

It is unclear to me why Amazon would be using KCR format in Kindle for Mac (and possibly Kindle for PC.) Perhaps it is being used to add support for one or more languages that KF8 does not handle well.

odamizu · 03-08-2019, 11:45 PM

Thanks jhowell! You are a font of wisdom

odamizu · 03-09-2019, 11:46 PM

I just had a really interesting experience experimenting with 1.25.2 after reading this post.

I downloaded K4Mac 1.25.2 and downloaded a few ebooks. As expected, I got what I think was KFX — an azw file along with a voucher file, azw.res, azw.md, etc.

I then ran chmod -x, which disables KFX on pre-1.25.2 K4Mac.

When I tried re-downloading my ebooks I was astonished to find ... kcr files!

What's really interesting is that first the file had an azw extension, then a few seconds later the extension changed to kcr. I'm guessing an azw file was downloaded first, then a kcr file followed immediately after, then the azw was immediatley deleted. I tried to capture the azw file before it changed to kcr, but it happened too fast and I failed every time.

So it appears kcr is the backup format that 1.25.2 delivers when KFX is not available or somehow disabled.

I tested this with several books, and it happened every time.

jhowell · 03-10-2019, 09:32 AM

Quote:

Originally Posted by odamizu

What's really interesting is that first the file had an azw extension, then a few seconds later the extension changed to kcr. I'm guessing an azw file was downloaded first, then a kcr file followed immediately after, then the azw was immediatley deleted. I tried to capture the azw file before it changed to kcr, but it happened too fast and I failed every time.

Very strange!

With the latest version of Kindle for PC, 1.25.1 (52064), I used the PC method of blocking KFX by renaming render-test.exe and it has no effect. Books still download in KFX format. No sign of KCR files.

There is something very different about how the new Kindle app works on PC and Mac.

odamizu · 03-10-2019, 04:28 PM

Curiouser and curiouser.

I was able to capture the azw file today. It is indeed KF8 and it can be liberated by Alf. More info starting here: https://www.mobileread.com/forums/sh...38#post3819438

Iris-maybe · 03-12-2019, 09:45 PM

Quote:

Originally Posted by jhowell

I saw signs that KCR support was added to Kindle for PC/Mac, but this is the first I have heard of it being used. KCR is the format used by Kindle Cloud Reader, the browser-based reading app. It is also used by the Kindle for iOS app in place of KF8 (azw3). Perhaps for some reason Amazon is dropping KF8 on the Mac platform as they did on iOS.

I would like to know more.

What is the build number of K4Mac you are using? This is the number in parenthesis after the main version number. As far as I know build 52077 is the latest downloadable version and build 52078 is the version available from the Mac app store.

Can you give an example of a book that is showing in KCR format for you?

Are you in the US and using amazon.com are you in another country?

The mac version is 1.25.2.(52077).
I am living in the US and the book title is "To be a sinner".

jhowell · 03-12-2019, 10:31 PM

Quote:

Originally Posted by Iris-maybe

The mac version is 1.25.2.(52077).
I am living in the US and the book title is "To be a sinner".

Thanks for getting back to me.

In the mean time odamizu was able to work out more of what is going on with Kindle for Mac and KCR.

03-07-2019, 03:16 AM	#1
Iris-maybe Member Posts: 24 Karma: 10 Join Date: Sep 2017 Device: kindle paperwhite2	Kindle for Mac1.25.2 with the new kindle format--.kcr? Kindle for Mac 1.25.2 is available now. No. kfx format, but .KCR. Any idea of this change?

03-10-2019, 04:28 PM	#9
odamizu just an egg Posts: 1,827 Karma: 7943430 Join Date: Mar 2015 Device: Kindle, iOS	Curiouser and curiouser. I was able to capture the azw file today. It is indeed KF8 and *it can be liberated by Alf. More info starting here: https://www.mobileread.com/forums/sh...38#post3819438 Last edited by odamizu; 03-11-2019 at 02:18 AM.*

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03-07-2019, 04:22 AM	#2
HarryT eBook Enthusiast Posts: 85,544 Karma: 93383099 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	Moved to the Kindle forum.

03-07-2019, 10:03 AM	#3
jhowell Grand Sorcerer Posts: 7,067 Karma: 91577715 Join Date: Nov 2011 Location: Charlottesville, VA Device: Kindles	I saw signs that KCR support was added to Kindle for PC/Mac, but this is the first I have heard of it being used. KCR is the format used by Kindle Cloud Reader, the browser-based reading app. It is also used by the Kindle for iOS app in place of KF8 (azw3). Perhaps for some reason Amazon is dropping KF8 on the Mac platform as they did on iOS. I would like to know more. What is the build number of K4Mac you are using? This is the number in parenthesis after the main version number. As far as I know build 52077 is the latest downloadable version and build 52078 is the version available from the Mac app store. Can you give an example of a book that is showing in KCR format for you? Are you in the US and using amazon.com are you in another country?

03-08-2019, 01:36 PM	#4
odamizu just an egg Posts: 1,827 Karma: 7943430 Join Date: Mar 2015 Device: Kindle, iOS	I just downloaded K4Mac and it's still 52077. I'm in the US using amazon.com. I haven't installed it though and don't plan to given the KFX problem. I thought iOS uses AZK. Or is AZK an older iOS format that's being replaced by KCR?

03-08-2019, 11:45 PM	#6
odamizu just an egg Posts: 1,827 Karma: 7943430 Join Date: Mar 2015 Device: Kindle, iOS	Thanks jhowell! You are a font of wisdom

03-09-2019, 11:46 PM	#7
odamizu just an egg Posts: 1,827 Karma: 7943430 Join Date: Mar 2015 Device: Kindle, iOS	I just had a really interesting experience experimenting with 1.25.2 after reading this post. I downloaded K4Mac 1.25.2 and downloaded a few ebooks. As expected, I got what I think was KFX — an azw file along with a voucher file, azw.res, azw.md, etc. I then ran chmod -x, which disables KFX on pre-1.25.2 K4Mac. When I tried re-downloading my ebooks I was astonished to find ... kcr files! What's really interesting is that first the file had an azw extension, then a few seconds later the extension changed to kcr. I'm guessing an azw file was downloaded first, then a kcr file followed immediately after, then the azw was immediatley deleted. I tried to capture the azw file before it changed to kcr, but it happened too fast and I failed every time. So it appears kcr is the backup format that 1.25.2 delivers when KFX is not available or somehow disabled. I tested this with several books, and it happened every time.

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