Which standalone mobi metadata editor should I use?

[Julius Caesar]

I want to modify a book that has typos and formatting issues by doing the following:
1. Unpack the original mobi file with KindleUnpack
2. Make modifications as necessary with the source files
3. Repack the source files with Kindlegen
4. Change the metadata of the new mobi file so that its meta would be as close as possible with the original mobi file

I have completed step 1 to 3. What software should I use for step 4? I don't want to use Calibre since it makes too many hidden changes in the background that I don't want. I just want a simple software that would let me fine tune the metadata.

[DiapDealer]

If you're trying to alter/rebuild a kindlebook while at the same time wanting the new one's EXTH record to look and smell exactly the same as the original to the Amazon system, you're probably wasting your time. Especially if it was originally DRMed.

If that's not what you're about, then I can't see your steps 1-3 significantly changing any relevant metadata in the first place. But MOBI metadata editor programs pop up around here from time to time. It shouldn't be too hard to find one. I can't testify to their "simpleness," though.

EDIT: also, if it's just standard ebook metadata (author, title, subject, etc) type stuff you're looking to tweak, you can easily tweak that metadata in the OPF file before rebuilding. Changing the metadata (on the fly) of a binary Kindlebook is no mean feat. That's probably why simple, standalone MOBI metadata editors aren't more prevalent than they are.

[Doitsu]

Originally Posted by Julius Caesar

I have completed step 1 to 3. What software should I use for step 4? I don't want to use Calibre since it makes too many hidden changes in the background that I don't want. I just want a simple software that would let me fine tune the metadata.

Check out Java Mobi Metadata Editor. BTW, if you want to sideload the book to the ebooks folder of an Kindle app, make sure that the .mobi file has an ASIN number metadata entry.

[Julius Caesar]

Originally Posted by DiapDealer

EDIT: also, if it's just standard ebook metadata (author, title, subject, etc) type stuff you're looking to tweak, you can easily tweak that metadata in the OPF file before rebuilding.

The problem is kindlegen ignores or changes some of the metadata in the opf file, so I would need to reenter the metadata manually or change them back after running kindlegen

[DiapDealer]

Originally Posted by Julius Caesar

The problem is kindlegen ignores or changes some of the metadata in the opf file, so I would need to reenter the metadata manually or change them back after running kindlegen

As I said previously: the standard ebook metadata (author, title, subject, etc) in the OPF doesn't get altered or ignored. So I assume you're talking about proprietary (non-standard) Amazon metadata. Which there's no real point in trying to duplicate (with the exception of Doitsu's advice to make sure there's an Amazon ASIN present so side-loaded stuff will continue to sync). You can't really "trick" them (other than the syncing) into thinking it's the original unaltered book anyway (especially since the DRM has likely been removed). So there's no real point in trying.

The editor Doitsu mentioned should allow you to put the ASIN back, but there's just no reason to put all those other proprietary Kindle token EXTH entries back. You can't put the genie back in the bottle.