Cover Image in LRF files

[pdurrant]

I'm trying to find the cover image in LRF files. I haven't managed to find any really detailed info about the file format on the web.

I have managed to find that in most (version >=800) files there is a tiny thumbnail gif, and I can successfully retrieve this.

But despite having looked through Calibre source, I can't find out where the cover is stored, although one ominous comment implied there wasn't a standard identifier for the cover.

Can anyone help, either directly or by pointing me to a documentation source?

Thanks.

Paul

[kovidgoyal]

LRF doesn't have a well defined cover. calibre uses some heuristics to guess at a cover. Naturally these heuristics work best with LRF files created by calibre

[pdurrant]

"Oh Bother!" said Pooh.

Originally Posted by kovidgoyal

LRF doesn't have a well defined cover. calibre uses some heuristics to guess at a cover. Naturally these heuristics work best with LRF files created by calibre

[kovidgoyal]

note that lrf-meta has a --get-cover switch which you can use to get the guessed cover

[pdurrant]

I saw the --get-cover switch when looking at Calibre's source, but trying to follow through the code to work out how to do the same in C/C++ is more than my very passing acquaintance with Python is up to in the time I have.

If you've put together some documentation of the LRF format as you've decoded it while working on Calibre, that would be very helpful. Anything similar to the documentation I added to the Mobipocket format wiki entry here:

https://wiki.mobileread.com/wiki/MOBI

Thanks again.

Originally Posted by kovidgoyal

note that lrf-meta has a --get-cover switch which you can use to get the guessed cover

[kovidgoyal]

I'm afraid I haven't done any documentation. But the LRf format is documented here http://www.sven.de/librie/Librie/LrfFormat

And SONY released the specification of the LRS format (the XML format of which LRF is the binary version).

[pdurrant]

Thanks again. Looking at what documentation there is again, and following more links to elsewhere I think I've cobbled together something that might work for some books, and shouldn't be worse than what I have at present.

In short, I'm assuming that the object referred to in the last item in the object index table is the cover image if it's a picture subfile.

Paul

Originally Posted by kovidgoyal

I'm afraid I haven't done any documentation. But the LRf format is documented here http://www.sven.de/librie/Librie/LrfFormat

And SONY released the specification of the LRS format (the XML format of which LRF is the binary version).