View Full Version : What are opf and mimetype files?


BookCat
10-20-2009, 07:48 AM
Two files have recently landed on my desktop, which is where I download everything to, but I don't know what they're for. I googled them and found that they are something to do with ebooks. What am I supposed to do with them?

I suspect it's an epub thing, but this doesn't help much when I don't know how to play with them. :smack:

Any help appreciated. I'm not much of a techie. :thanks:

wallcraft
10-20-2009, 08:03 AM
A .epub file is a renamed .zip file, and two of the files in the ZIP are called mimetype and something.opf. So you most likely downloaded an ePub file but your web browser treated it as a .zip and automatically unzipped it. If so, I would expect them to be in a folder, rather than actually on your desktop as files. If so, the easiest thing to do is delete the folder and redownload the .epub file without unzipping it.

The Sony ebook library should have been associated with .epub files in your browser (I think). If you install Adobe Digital Editions it should certainly be associated with .epub files and prevent unzipping on download.

BookCat
10-20-2009, 08:51 AM
Thank you for your info, Wallcraft. I'll delete the files.
I've had problems with Adobe Digital Editions. When I install it, it freezes. I asked for advice about this in another thread and came to the conclusion that as the Sony software can usually transfer epubs with no problem, it's just the odd Harlequin freebie I have this problem with. So I uninstalled ADE and can live without the Harlequins. I did message Harlequin books about this, but have no reply.
Thanks.

Critteranne
12-13-2009, 09:21 PM
From what I have read, OPF came out of the original Open eBook format:
http://en.wikipedia.org/wiki/Open_eBook

When I convert LIT files into HTML (for use on my eBookwise), I also end up with .opf files. I used to ignore them and then create ebooks out of the multiple HTML files -- with much grumbling as chapters always end up out of order. What I learned eventually was that I could drag the OPF file into the eBookwise Librarian program. It then uses the .opf file to create an IMP file that contains all the HTML files, plus cover images, etc. Doh!
:smack:

I don't know which other programs can work the same magic with the OPF files, however.

user_none
12-15-2009, 09:10 PM
The opf file specifies what files represent the book and how. Chapter order, table of contents, cover...

Critteranne
12-15-2009, 09:35 PM
The opf file specifies what files represent the book and how. Chapter order, table of contents, cover...

So it's like a playlist for books? :)

user_none
12-15-2009, 09:44 PM
So it's like a playlist for books? :)

In a sense yes. If the playlist is for a single album. The opf file is only for one book not many. It also stores the metadata for the book.