Dealing with Kindle for PC/Mac 1.19 and KFX in calibre

[legitimateliv]

I'm at 10.14.3 (18D109). Calibre 3.40.1. DeDRM version 6.6.1. Kindle 1.25.2 Last updated on 1/1/2019.

I just rechecked the whole thing. If I set chmod -x ./renderer-test, then I get a single file azw (for some books there are apnx, phl and mbpV2 files) but I'm able to import into calibre and read them. If it's +x then its a no-go.

However I just checked on another mac, which never had kindle for mac installed and synced to a different amazon account and setting -x did not help. Even though it downloads single-file azw and calibre can read the metadata, I cannot open and read the book. This was K4M 1.25.2 and DeDRM 6.6.2

I have a suspicion that since I set -x on K4M 1.23 and then let it update to 1.25, I just got lucky.

[bkennelly]

That suggests something. (I don't have a Mac to test, so it is purely a guess on my part.)

Try creating a file named renderer-test in the K4M directory on the "new" Mac and make sure it is non-executable. It might fool the program...

[odamizu]

To skip the discussion and go straight to the solution for getting Alf-friendly KF8 out of Kindle for Mac 1.25.2, see this post:
https://www.mobileread.com/forums/sh...&postcount=508

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This is getting more and more fascinating.

Today, I was able to capture the azw file, and it is indeed KF8/azw3. What's more, it can be liberated by Alf. Further experiments suggest that K4Mac 1.25.2 cannot read KF8. It can only read KFX and KCR, and when it encounters KF8, it automatically replaces it with KCR.

But, if you're fast enough, you can use K4Mac 1.25.2 to get a KF8 file that works with Alf.

The question is how legitimateliv was able to prevent 1.25.2 from downloading the KCR file and deleting the initial KF8 file (which has an azw extension) replacing the initial KF8 file (which has an azw extension) with a KCR file.

Details of what I did:

1) Clean install K4Mac 1.23.1
- Download a few ebooks, which all arrive as KFX (with the generic .azw file extension)
- Use chmod -x to make renderer-test non-executable
- Delete ebooks and re-download
- Re-downloaded books arrive in KF8 format with generic .azw file extension
- Alf successfully liberates re-downloaded KF8 files

2) Allow K4Mac 1.23.1 to update to 1.25.2
- Try to open ebooks previously downloaded by 1.23.1 (which are in KF8 format because renderer-test had been disabled per above). Pop-up window appears saying "Preparing your book ..." Go to My Kindle Content folder and find that the .azw/KF8 files have been replaced with .kcr files, which can now be opened and read
- Download a few additional ebooks. These all arrive as KFX (with the generic .azw file extension)
- Use chmod -x to make renderer-test non-executable
- Delete ebooks and re-download
- The first file that appears has an .azw extension. This is quickly followed by a .kcr file, then the .azw file is deleted
- Quickly, before the .azw file is deleted, drag it to the desktop. (Note: I checked the Trash bin to see if the deleted .azw file ends up there, but sadly no. So it's not as easy as retrieving the file from Trash)
- Alf successfully liberates the .azw file dragged to the desktop, which turns out to be KF8

3) Clean install K4Mac 1.25.2
- Same thing happens with clean install of K4Mac 1.25.2 as when you start with 1.23.1 and allow it to update

Additional tests:
- Put unliberated .azw/KF8 file that was dragged to the desktop back in My Kindle Content folder and delete the .kcr file. Try to open ebook. K4Mac says "Preparing your book ..." downloads a .kcr and deletes the .azw file and replaces the .azw file with a .kcr file
- Go to .azw/KF8 file that was dragged to the desktop and try to open it directly from the desktop using "Open with ..." command and choose K4Mac 1.25.2. Same thing happens: K4Mac "updates" it by downloading a .kcr and deleting the .azw file replaces the .azw file with a .kcr

It does seem that K4Mac 1.25.2 cannot read KF8, and when it encounters one, it automatically replaces it with a KCR file. And yet, if you use chmod -x to disable renderer-test to prevent KFX, K4Mac 1.25.2 will download a KF8 file (with a generic .azw extension), and if you're fast enough, you can drag it to your desktop before it disappears and liberate it with Alf.

Now we need to figure out how to prevent K4Mac from deleting the initial .azw and downloading replacing it with a .kcr — which seems to be happening on legitimateliv's Mac.

Originally Posted by bkennelly

That suggests something. (I don't have a Mac to test, so it is purely a guess on my part.)

Try creating a file named renderer-test in the K4M directory on the "new" Mac and make sure it is non-executable. It might fool the program...

There is already a file named renderer-test. The chmod -x command doesn't delete it, it makes it non-executable.

[jhowell]

Originally Posted by odamizu

Today, I was able to capture the azw file, and it is indeed KF8/azw3. What's more, it can be liberated by Alf. Further experiments suggest that K4Mac 1.25.2 cannot read KF8. It can only read KFX and KCR, and when it encounters KF8, it automatically replaces it with KCR.

Great work!

Hopefully someone can come up with a method of blocking the KCR file download. That would provide a path forward with Kindle for Mac for those who plan to upgrade to a 64-bit only OS.

------

I have a suggestion of something you could try. Perhaps the file is downloaded normally and only replaced when you attempt to open it.

On Kindle for PC double clicking a book icon causes it to be both downloaded and opened, but right clicking and selecting "Download" causes a download only. I assume Kindle for Mac works similarly.

[odamizu]

Originally Posted by jhowell

... I have a suggestion of something you could try. Perhaps the file is downloaded normally and only replaced when you attempt to open it.

On Kindle for PC double clicking a book icon causes it to be both downloaded and opened, but right clicking and selecting "Download" causes a download only. I assume Kindle for Mac works similarly.

BRILLIANT!!!!!!

Your hypothesis was spot-on. Right-clicking and selecting "Download" triggers a KF8 file (with the generic extension .azw) to download without opening the book and without triggering a KCR to follow and replace it. Whereas double-clicking causes a KF8 to download (if it hasn't already been downloaded), immediately followed by a KCR, then the KF8 is deleted and the book opens.

Mac users can now use the 64-bit K4Mac 1.25.2 to download an Alf-friendly KF8 (with .azw file extension) by using chmod -x to disable renderer-test then right-clicking and selecting "Download." It is imperative that one not double-click and open the book as that will delete the Alf-friendly KF8 and replace it with a not-friendly-to-Alf KCR.

For complete instructions see this post:
https://www.mobileread.com/forums/sh...&postcount=508

[jhowell]

Originally Posted by odamizu

Right-clicking and selecting "Download" triggers a KF8 file (with the generic extension .azw) to download without opening the book and without triggering a KCR to follow and replace it.

That is great news!

I still find it odd that the program downloads a KF8 file and then later downloads the same book as KCR. Is it possible that the first is actually being converted into the second? One way to test that would be to download a book and then disable your Internet connection before you try to open it.

[odamizu]

Originally Posted by jhowell

... I still find it odd that the program downloads a KF8 file and then later downloads the same book as KCR. Is it possible that the first is actually being converted into the second? One way to test that would be to download a book and then disable your Internet connection before you try to open it.

You are a genius! I did as you suggested, and that's exactly what's happening.

I downloaded a book without opening it, and got an .azw/KF8.

I then disconnected from the Internet and opened the book. A few seconds later the KF8 disappeared and a .kcr appeared. Since my Internet was disconnected, it obviously wasn't downloaded.

This all makes so much more sense now. When KFX is blocked using chmod -x to disable renderer-test, K4Mac 1.25.2 downloads a KF8, then when you go to open the book, it converts it to KCR.

The question is why has Amazon switched from KF8 to KCR as the alternate format when KFX is blocked?

Also, whenever I close 1.25.2, it crashes with a "Quit Unexpectedly" warning. I'm guessing this is because I disabled renderer-test. This doesn't happen with 1.23.1.

[legitimateliv]

This make sense. When I first reported this, I was using a keyboard macro mapped to "File > Download" menu item in the K4M app, so it was only downloading (and not opening) an azw/kf8 file and not the kcr file.

I can also reproduce everything mentioned in this thread. With -x, right click download gets an azw file which Alf can deal with. Double click gets a kcr file which Alf can't. With +x, everything is useless.

[jhowell]

I updated the first post in this thread to link to the new information by odamizu for getting Method 2 working with the latest Kindle for Mac.

[odamizu]

@legitimateliv: Does your K4Mac 1.25.2 crash with a "Kindle quit unexpectedly" error message every time you close it? Thanks

[odamizu]

Originally Posted by jhowell

I updated the first post in this thread to link to the new information by odamizu for getting Method 2 working with the latest Kindle for Mac.

As Amazon is making it increasingly difficult to obtain KF8/AZW3 using K4Mac, this post is no longer being actively maintained, and the info provided may be increasingly outdated. That said, if you want to try Method 2B on K4Mac 1.25 thru 1.31 (which reportedly works for ebooks published in or before 2022, but no longer works for ebooks published starting 2023) ...

• Apply chmod -x or sudo chmod -x (Method 2B), then download books using right-click on mouse and selecting "Download", or use menu bar "File > Download". Do NOT open the book. If you open the book, you end up with .kcr, in which case delete the book and re-download per above without opening it.
  

[legitimateliv]

Originally Posted by odamizu

@legitimateliv: Does your K4Mac 1.25.2 crash with a "Kindle quit unexpectedly" error message every time you close it? Thanks

Most of the times, yep.

[odamizu]

Thanks. I'll probably stick with 1.23.1, then. Though it's good to know that if necessary, it's possible to get Alf-friendly KF8 from 1.25.2.

P.S. I restored renderer-test using chmod +x and 1.25.2 immediately stopped crashing on quit, so it's definitely due to this modification.

[jhowell]

Originally Posted by odamizu

@jhowell: Thanks for updating the first post with instructions for Mac users. It's actually not necessary to install 1.25.2 on top of an older version. It works with a clean install of 1.25.2 as well.

OK. I have updated the first post and linked it to you new post.

[anon_me]

I have tried both 1.23.1 and 1.25.2 with the 'renderer-test' workaround and no matter what I get the .azw / .res / .md files. I never see any other files appear first and this is with using the right-click download method.

Suggestions?

Update: Even though I received no errors in Terminal I had to run the renderer-test chmod command with sudo. Seems to have worked as expected after that, at least on 1.23.1