Add ZIP and RAR formats to book

[mysernameisalrea]

Hi,

I've got some ZIP and RAR files that have compressed .epub versions of some books in my Calibre library. I like to keep these compressed files as backup incase the .epub file gets corrupted. When I try to add the compressed file to my books, it appears that Calibre is automatically extracting the contents of the compressed file.

What I'd like is that in the Edit Metadata window, the small box on the right that shows the various formats of the book, for it to show EPUB, MOBI and ZIP/RAR.

If I try to add a compressed file that has MULTIPLE formats inside (i.e. the compressed file contains the EPUB and MOBI versions of the book) then Calibre does add RAR or ZIP as a format in the "Formats" column. But if the compressed file only contains a single format, Calibre just automatically extracts it and the compressed file isn't listed in the "Formats" column.

Is there a way to force Calibre to show the ZIP and/or RAR file in the "Formats" column even if the compressed file only contains a single format?

Thanks in advance.

[gbm]

Export your format to disk, then rename it by adding .bak after the file type.zip
example:

Kristine Kathryn Rusch Diving Into the Wreck.epub.bak

Then zip or rar it, drag and drop it into the Book Details panel for that book or go to Add books and use Add file to selected book records.

bernie

Originally Posted by mysernameisalrea

Hi,

I've got some ZIP and RAR files that have compressed .epub versions of some books in my Calibre library. I like to keep these compressed files as backup incase the .epub file gets corrupted. When I try to add the compressed file to my books, it appears that Calibre is automatically extracting the contents of the compressed file.

What I'd like is that in the Edit Metadata window, the small box on the right that shows the various formats of the book, for it to show EPUB, MOBI and ZIP/RAR.

If I try to add a compressed file that has MULTIPLE formats inside (i.e. the compressed file contains the EPUB and MOBI versions of the book) then Calibre does add RAR or ZIP as a format in the "Formats" column. But if the compressed file only contains a single format, Calibre just automatically extracts it and the compressed file isn't listed in the "Formats" column.

Is there a way to force Calibre to show the ZIP and/or RAR file in the "Formats" column even if the compressed file only contains a single format?

Thanks in advance.

[BetterRed]

@mysernameisalrea - because an ePub is already compressed (zipped) - except for the mimetype file - compressing an ePub won't buy you much disk space.

BR

[DNSB]

Originally Posted by BetterRed

@mysernameisalrea - because an ePub is already compressed (zipped) - except for the mimetype file - compressing an ePub won't buy you much disk space.

BR

The last time I tested compressing 14 epubs I was sending back to the author after doing some cleanup and proofreading, the total savings on 14 separate compressed files was ~13KB. If I compressed all 14 files into a single archive, I got the following results using 7Zip:

Zip (Ultra, deflate64) 10,219,633 bytes
7z (Ultra, lzma2)       9,848,355 bytes
Zip (store only)       10,251,096 bytes

If I didn't use 7Zip's maximum compression settings, the savings were even less. A couple of cases such as zip format, normal compression, LZMA actually used more space than the store only option.

[mysernameisalrea]

Ahh, okay. I didn't realize that .epub was already a type of compressed file. Now I understand what Calibre is doing.

I'm not using the compressed zip/rar files as a means to save space-- that's just how I got them, so I'm saving them as a backup. As such, thanks @gbm for suggesting I append ".bak" to my these compression files. I'll do that.

[itimpi]

Originally Posted by mysernameisalrea

Ahh, okay. I didn't realize that .epub was already a type of compressed file. Now I understand what Calibre is doing

epub is actually a zip file that has specific file structure internally. You can see this by changing the extension of such a file from .epub to .zip and then opening it in your favourite zip file handler.

[compurandom]

Originally Posted by itimpi

epub is actually a zip file that has specific file structure internally. You can see this by changing the extension of such a file from .epub to .zip and then opening it in your favourite zip file handler.

Or use calibre "unpack book" to do the same thing.
I use to do that a lot, but the editor does so much now that it's been a while...

[drjenkins]

Keeping your backup files in the same folders as the originals rather defeats the purpose of a backup. Better to keep a backup copy of your libraries on separate media, like a file share or external hard drive.

[DNSB]

Originally Posted by mysernameisalrea

Ahh, okay. I didn't realize that .epub was already a type of compressed file. Now I understand what Calibre is doing.

I'm not using the compressed zip/rar files as a means to save space-- that's just how I got them, so I'm saving them as a backup. As such, thanks @gbm for suggesting I append ".bak" to my these compression files. I'll do that.

I'd suggest not worrying about the filename and storing in your calibre library. I keep my backups on external hard drives and in the cloud since having backups on the same computer as the originals is no protection from a hard drive failing, data corruption, getting hit by ransomware or whatever other bits of paranoia I come up with in the middle of the night.