how do i output MOBI instead of AZW3?

[combbbb]

how do i output MOBI instead of AZW3?

[leotaku]

Hi! For what reason do you want to do this? The formats MOBI and AZW3 kind of blend into each other, with AZW3 being basically just MOBI with Amazon extensions for Kindle.

If your reader only supports "pure" MOBI and not AZW3, it is unlikely it will be able to display manga/comics.

[combbbb]

hi, so the reason is, that kindle only shows the covers of sideloaded ebook in lockscreen if they are in mobi format. in azw3 this doesn't work unfortanetly. thats why i always used kindle comic converter. but ofc would be nice if i can leave out that step with kojirou

[leotaku]

Interesting, I will have to look into that. Basically I would have to find out, how the reader decides that a file is "MOBI" for the purpose of showing the cover.

Do you know if this behavior is documented anywhere else, e.g. on GitHub or forum threads?

[combbbb]

i didn't really look for any documentation of this problem. but i just tried it again and with mobi and azw3. same result. azw3 never shows the cover when kindle is in standby - with mobi no problem.

[leotaku]

How are you converting from AZW3 to MOBI? Are you simply changing the file extension, or using some tool to perform the conversion?

[combbbb]

i just convert the cbz from another source to mobi with kindle comic converter.

for both instances i use calibre to load the book onto my kindle.

they both turn up with covers in the gallery/library view but as a lockscreen/standby cover only the mubi file will show the cover.

[baobach]

Here is my experience with this mobi format. I used to own a Kindle but now I just purchased a Boox device so I need mobi files for the reading app. I have looked around GitHub and tbh Kojirou is by far the best Mangadex downloader I have ever tried. But the awz3 format doesn't work for me so I decided to change the file extension to .mobi and it works like a charm. I think you can add one option for the output to be saved in .mobi instead and this can be used for every single e-reader on earth.

[leotaku]

Ok, there seems to be two different issues here:

1. Some third-party readers can actually read more modern MOBI files, but only accept the mobi extension not azw3.
2. Kindle devices only show the cover on the lockscreen if the file is MOBI/maybe some other flag is set. (I've been able to confirm this on my device)

Issue 1. should be easily fixed by adding an --extension flag to the application, but issue 2. will be much harder. Just renaming the generated AZW3 to MOBI causes my Kindle to no longer be able to open the file. Someone would have to do some binary sleuthing to find what the differences between a valid "mobi" and "azw3" file are.