Hi,
To make this clearer, for this discusssion let's ignore the source zip archive stored in one record inside the .mobi file when generated with kindlegen ... and just talk about the format of a K8 (mobi) azw3 file:
- it is NOT simply an epub wrappered into a Mobi
To see this, look at the huge amount of code in KindleUnpack that takes a processed kf8 database file (as generated by kindlegen or downloaded from Amazon) and tries its best to create an epub-like structure from it.
You can enable the "raw" mode to see what the actual pre-processed text inside the .azw3 looks like and you will see all file names are removed, all links are encode by byte position, how svg is extracted, how css is extracted and collected, etc.
You can enable "debug" mode to see all of the processed indices that are used to create entry and exit point offsets used to split that text into separate chapters and fragments. There are also indices that are used to store the NCX and other navigation pieces.
Of course the metadata is stored in the Mobi header and created partially from the opf and partially form other sources.
All of this needs to be "undone" to create an "epub-like" structure from the .mobi record database that an .mobi or .azw3 really represents.
This should make it abundantly clear that a mobi file created by kindlegen is nothing similar to an actual epub just wrappered, it is instead a highly preprocessed database of records and offsets that mimics/extends the original .mobi format.
That said, almost all of the information in an epub has its equivalent in a KF8 mobi and anything supported by the various versions of WebKit should work equivalently in an epub and a KF8.
Hope this makes things clearer.
Ask if you want more details about what the internal structure of a kf8 (or Kindlegen) generated mobi looks like, I would be happy to describe the epub-extraction process in detail.
Take care,
KevinH
Quote:
Originally Posted by Notjohn
This is very strange! The downloaded, converted book file does not contain the original submission, but it (the original submission) is later tucked into the file at an invisible "Step 7"? (Or has Kindleunpack ignored one of the two files, either my original submission or the epub-plus-wrapper as you neatly describe it?)
So the answer to my original question is: Qualified Yes? Amazon is delivering epubs-in-a-wrapper to owners of the Fire and related devices and apps?
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