Originally Posted by adamselene
So I actually decided to try the splitting feature, to see how much space it would save on a Kindle loaded with converted ePub books. The answer turned out to be about 11.5% on my corpus of 1277 books. But that's not what this post is about…
I compared a KF8 stripped by KindleUnpack with one generated from the same original file by Amazon's Personal Document Service, and found that, aside from some minor changes in the metadata (including addition of the atv:kin:1 tag that they harvest and upload to track documents), it does something different with DATP sections near the end of the document. There are two in the original file and the KindleUnpack KF8, but one is removed in the Amazon KF8, and it's put in a slightly different location in the file. I wonder whether this matters. Do you have any idea what this section is for? It looks like a table of offsets.
Most of this is beyond me, but if I may, you can't actually "generate" a K8 file from Amazon's PDS
. If you email a file to your own Kindle addy, or use the PDS in any other way, what you get back is not a K8; it's the old mobi (prc) format. So, you can't compare apples-to-apples (in any sense) for an actual K8 created by KindleGen/KP versus the "mobi" (prc) file that you'll get from PDS. You can test this yourself by sending a K8 with, say, an embedded font to the PDS--what you get back will be equivalent to a book made with MBPC. Then sideload the same K8 file with an embedded font to a Fire device directly, either by USB or via an actual (not faux) wifi connection. The "send to Kindle by wifi" prompt you can see on your computer does not use Wifi; it emails the document/book via the PDS
. So when I say "wifi," I mean an app like "Wifi File Explorer," which is genuine wifi. You'll see the difference; the USB or wifi-d book will have the embedded font; the PDS book will not.
Hope that helps. The DATP stuff is too deep for yours truly, but I thought before you tried to sort this, you should use files that are equivalent.