How to convert pdf to eBook format Is there a way to convert a PDF document into an eBook format such as epub, azw or mobi? I am looking for an application, which is fast in conversion. I have just tried calibre. After 10 minutes not even 2% of the conversion have been reached. So please no calibre. CLI is preferred.

You should try `pdftotext` (comes under Ubuntu in the package `poppler-utils`). It is a commandline converter. It assumes that the PDF has text and does not consist of images only.

If the PDF file consists of images (without OCR info), you have to go for an OCR solution, which is much slower.

I have successfully used the OCR method as well on PDF text which was scrambled (by positioning the individual characters on a page in a non-linear fashion). Then you use e.g. `pdftoppm` to get individual images of the pages and OCR those.