@jhowell: I'm not quite sure who (you or @NiLuJe) and which of the 2 forum topics would be more appropriate person & place to ask for help with trying to troubleshoot a bug regarding KFX files generated with this KFX Output plugin + @NiLuJe's
ScreenSaver hack used in "Cover mode" (= "book cover as a screensaver" thing).
The problem: only for KFX books generated via Calibre using KFX Output addon ( = for couple of KFX books downloaded from Kindle Store the correct image is extracted and used as a screensaver by SS hack) the SS hack doesn't pick / extract & use correct image as a screensaver image (the cover image, that was correctly marked as such in input epub file) . Instead it picks a random? (it not using the first or last or Nth file as ordered inside epub's manifest) image contained inside the book file and usually it is quite small, like something used for chapter headings or separators / scene breaks.
The sideloaded KFX files were created on Windows 10 x64 (build 21H1) using:
- latest version (v.1.59.0) of KFX output addon
- Calibre v5.37 64-bit
- Kindle Previewer 3.61.0
I'm using latest version (v0.25N @r18833 on 2021-Nov-15 @00:37) of ScreenSaver hack
from snapshots on a Kindle Paperwhite 3 with
firmware version v5.9.7.
Just in case here are link for 2 book conversion logs but I doubt they will be of any use since "Show full Kindle Previewer conversion logs" option wasn't selected at the time of those conversions.
https://pastebin.com/jK1dLDQJ
https://pastebin.com/6bhvfgaf