What should be in a MOBI file?

[seanos]

This a bit of an odd question, but my experience of MOBI is a bit limited and I wasn’t 100% sure if this file was as strange as it seems.

From the quality of their ePUB, I’m guessing that this new publisher doesn’t quite know what he’s doing, but anyway here’s what’s Calibre’s KindleUpack gives me...

\mobi7\
\mobi8\
kindlegenbuild.log
kindlegensrc.zip

Is it normal to include this source file in the MOBI? It’s 4MB of the files’ ~5MB.

The ePUB edition is ~3.5MB because it has a huge resolution cover (3.2MB vs. 111KB in MOBI edition). There doesn’t seem to be a very coherent strategy here.

[Doitsu]

Originally Posted by seanos

Is it normal to include this source file in the MOBI? It’s 4MB of the files’ ~5MB.

It's not normal to include the source files in .mobi intended for end users, but OK for KDP, because Amazon will strip the source files from the .mobi and deliver either the mobi7 or mobi8 content to the end user.
It the publisher intends to distribute the .mobi file though their own website, they should offer mobi7 and mobi8 files for download.

[eschwartz]

For this reason, the devs here have developed this tool:

(sticky thread) Kindlestrip Python script and AppleScript wrapper

[DaleDe]

Originally Posted by eschwartz

For this reason, the devs here have developed this tool:

(sticky thread) Kindlestrip Python script and AppleScript wrapper

This is the answer but you need to ask the right question. What you saw was the standard output from KindlePreviewer or KindleGen. When they create a file it contains the source and two different versions of the compiled file assembled in a special way so that a regular Amazon reading product can read it directly. A reading product that can only read KF7 formatted files will only find the KF7 portion of the file and KF8 capable readers will find the new format and use it. Yes, the file is 3 times as big or more than it should be. As mentioned the above tool will split it very much like Calibre did and it can even be disassembled to reveal a rebuilt source look alike (although files names will not be recovered). Read about all of this in our wiki.

The full file is submittable to Amazon but they will reformat it for delivery to the final user. There is another format possible from KindlePreviewer and this is called AZK which is specific for iOS devices. It is also covered in the wiki.

Dale

[seanos]

Thanks for the enlightenment. I suspected it was something along those lines, but what I was really trying to gauge was whether the publisher knew what he was doing.

So, e-mailing that file (since his web purchasing wasn’t working), although a little odd, was probably an OK thing to do as far as compatibility goes. Now that I’ve started re-editing his ePUB version though, I’ve also noticed bad formatting in the MOBI too like multiple blank lines in the TOC. The ePUB has no TOC by the way.

I find this rather sad in itself, but I also know the author and feel like his work is not being respected.

[DiapDealer]

Originally Posted by seanos

since his web purchasing wasn’t working

Originally Posted by seanos

I find this rather sad in itself, but I also know the author and feel like his work is not being respected.

Make sure your author friend knows that technically/legally, if his publisher is creating his ebook with Amazon's conversion tools (Kindlegen, Kindle Previewer), then it can't be sold anywhere BUT on Amazon. Free distribution is fine, but if it's going to be sold at an independent vendor/website, that's in violation of the terms for using the software.

I have no idea how aggressive they are at policing that sort of thing (if they do at all), but it's best to know the details up front. "Better safe than sorry" and all that jazz.

[seanos]

The publisher does have his Amazon Store iframed into his site so I’m guessing the e-mailing business was just because he hadn’t got it uploaded to Amazon when he was offering a pre-order. He had to e-mail me my ePUB too.

Another oddity of the e-mailed file is that the mobi8 folder contains an ePUB, different to the one I got, (whole and extracted). Is that normal? Or does it just mean that an ePUB version was used as the source?

[DiapDealer]

Originally Posted by seanos

The publisher does have his Amazon Store iframed into his site so I’m guessing the e-mailing business was just because he hadn’t got it uploaded to Amazon when he was offering a pre-order. He had to e-mail me my ePUB too.

Another oddity of the e-mailed file is that the mobi8 folder contains an ePUB, different to the one I got, (whole and extracted). Is that normal? Or does it just mean that an ePUB version was used as the source?

KindleUnpack creates that epub during the unpacking process. Unnecessary in this case since the original source archive was included. But most end-users don't get their hands on the raw kindlegen output package that you have.

Technically you don't even have to unpack the file to get at the source archive. Most archiving software will be able to open/extract the zipfile that's appended to the .mobi directly.

The ePub in the zipfile is the "original." The one in the mobi8 folder is KindleUnpack's best guess at what that original might have looked like (because it's not usually included). Filenames, for instance, are lost in the compilation process.

[seanos]

Thanks for explaining that...I was a little unsure where the dividing line between content and reconstruction was.