epub to mobi conversion confusing

[bob.f]

I have a number of books that each exist in a number of formats, namely .epub, .mobi, .azw3 and .original_epub.

I want to batch convert each .epub to .mobi.

However when I do the conversion, in batch or individually, the .mobi I end up with does not reflect the .epub file. I suspect what is happening is the conversion is using the .original_epub as source. Evidence of this is that if I remove the .original_epub and redo the conversion the resulting .mobi file is as expected.

Is this the expected behaviour, and if so could someone please explain why this is?

[theducks]

Preferences Behavior has an INPUT FORMAT list. The order biases the conversion choice. (except for the Original_*)

As for using Original_*, that is as designed
BUT
there is a (preferences: tweaks

ID: save_original_format

When calibre does a conversion from the same format to the same format, for example, from EPUB to EPUB, the original file is saved, so that in case the conversion is poor, you can tweak the settings and run it again. By setting this to False you can prevent calibre from saving the original file. Similarly, by setting save_original_format_when_polishing to False you can prevent calibre from saving the original file when polishing.

I turned it OFF. I also gave up doing same format conversions in 99.9% of the cases. I find it faster-easier to edit EPUB or AZW3 stylesheets by hand while looking at the code than trial-error conversion of the same format (A clean EPUB/AZW3 usually converts to other formats just fine for my use)

[stumped]

Yes original_epub is always used in a conversion if itnexists and you cannot override it.
I recall asking about that's ages ago.
For a single book you can sneakily move that format out of its folder so that calibre conversion cannot find it and put it back once conversion has started. Then it uses epub.
But for batch. That would be messy. I don't think windows has a bulk undo move option so you would have to manually put each one back where it came from.
The only other option is to delete or archive away the original epub format file.

The only answer I got to Why ,was that "it is designed that way." You can ask Why is it designed that way but I doubt you will get far

[ilovejedd]

Originally Posted by stumped

Yes original_epub is always used in a conversion if it exists and you cannot override it.
I recall asking about that's ages ago.
For a single book you can sneakily move that format out of its folder so that calibre conversion cannot find it and put it back once conversion has started. Then it uses epub.
But for batch. That would be messy. I don't think windows has a bulk undo move option so you would have to manually put each one back where it came from.
The only other option is to delete or archive away the original epub format file.

The only answer I got to Why ,was that "it is designed that way." You can ask Why is it designed that way but I doubt you will get far

Iirc, the original_* files were meant as a way to recover from bad conversions/mods. Hence, the assumption is the regular version is a bad copy so the original is always used.

What I do is create a selective mirror of the library using Robocopy.

robocopy "main lib" "epub convert lib" /if *.db *.json *.epub /xx /mir

Run the conversions on the target library, then copy the resulting files to the main library.

robocopy "epub convert lib" "main lib" /if *.mobi *.azw3 /xx /mir /maxage:1

Then just fix file sizes using Quality Check plugin.

Granted, this uses more storage but I've got sufficient space to spare and I can always buy more or bigger drives if needed.

[stumped]

Originally Posted by ilovejedd

Iirc, the original_* files were meant as a way to recover from bad conversions/mods. Hence, the assumption is the regular version is a bad copy so the original is always used.

What I do is create a selective mirror of the library using Robocopy.

robocopy "main lib" "epub convert lib" /if *.db *.json *.epub /xx /mir

Run the conversions on the target library, then copy the resulting files to the main library.

robocopy "epub convert lib" "main lib" /if *.mobi *.azw3 /xx /mir /maxage:1

Then just fix file sizes using Quality Check plugin.

Granted, this uses more storage but I've got sufficient space to spare and I can always buy more or bigger drives if needed.

that is a neat idea.
i don't do bulk conversions, so I am happy to sneakily move the original format out of calibre library , then put it back afterwards.
it only happens when I wand a conversion of something I have fine-tuned for reading in epub e.g. I want to take a copy with me on a kindle
For safety, I don't like to delete the original format until I have actually finished reading the book in question, just in case I discover a bug

[bob.f]

Thanks to all for your comments.

[drjenkins]

Originally Posted by stumped

The only answer I got to Why ,was that "it is designed that way." You can ask Why is it designed that way but I doubt you will get far

The only time I have seen original_epub files was when I did epub to epub conversions. If the converted file is the better of the two I would delete the original_epub. If you do not delete it the presumption is that original_epub is the better source for conversion. It was, after all, the source for your current file.

[DNSB]

Originally Posted by drjenkins

The only time I have seen original_epub files was when I did epub to epub conversions. If the converted file is the better of the two I would delete the original_epub. If you do not delete it the presumption is that original_epub is the better source for conversion. It was, after all, the source for your current file.

Using Polish or Modify Epub also generates an original_epub file. Possibly other modification tools but those two I use rather often.

[lumpynose]

I wish I'd known about the Modify Epub plugin some time ago. I like that it merely appends to the epub's style file the Extra CSS from Calibre's Common Options > Look & Feel > Styling when you select Modify Epub's Append Extra CSS box. Even though I don't worry about Calibre damaging anything when doing an epub to epub conversion, for the simple stuff I want (ragged right and no space betwen paragraphs) Modify Epub is just the ticket.

[jackie_w]

Originally Posted by DNSB

Using Polish or Modify Epub also generates an original_epub file. Possibly other modification tools but those two I use rather often.

There's are 2 options in Prefs - Tweaks to change the original_ behaviour for anyone who wants to.

save_original_format = True/False controls what happens during conversions

save_original_format_when_polishing = True/False (as the name suggests) during Polishing

[DNSB]

Originally Posted by jackie_w

There's are 2 options in Prefs - Tweaks to change the original_ behaviour for anyone who wants to.

save_original_format = True/False controls what happens during conversions

save_original_format_when_polishing = True/False (as the name suggests) during Polishing

Personally, I want the original file kept. I've had several occasions with malformed epubs where Polish and/or Modify Epub got garbage in and spewed scrambled garbage out. Hence, I now open new epubs in either Sigil or calibre's editor and run the various checkers before any file change operations.