"On the fly"-creation on own server

[AgeG]

Hi there,

we are looking for a solution to insert a transactional watermark to an ebook (epub), that gets inserted after a user bought the ebook.
E.g. his username/name get inserted in the ebook or some/all images get the some sort of ID in the metadata that is related to the buyer.

We don´t mind people sharing their ebook with friends, but we would like to make it a little more difficult for those, who would upload the ebook to filesharing websites. (I know the watermark can get removed and therefore this method is not perfect, but that´s ok. It should just be little more difficult for non-technical guys.)

Steps:

1.) User buys ebook in epub format
2.) Watermark gets inserted in ebook
3.) Ebook gets created
4.) User receives download link via email

I wonder, if Calibre might be the software to use for the “on the fly” ebook creation on the server?
Or are there other/more suitable tools for “on the fly” online creation of ebooks on our own server?

I am aware, that the watermarking would need to be done with a custom script and is not part of what Calibre offers.

Thank you very much for your feedback.
AgeG

[theducks]

IMHO the best watermark is the one that appears to 'belong' in the book and not stick out like a signpost.

Calibre is not intended to do this type of actions.

The Help section at the download site lists the CLI tools (part of Calibre) available.

[AgeG]

Originally Posted by theducks

Calibre is not intended to do this type of actions.

was this meant concerning the "on the fly"-creation process on server?

That I will need a custom script for the watermarking, as it´s not included with Calibre - that I know.

I was more asking for dynamic creation process of an ebook on our server and whether Calibre might be the right tool for that.

[theducks]

Originally Posted by AgeG

was this meant concerning the "on the fly"-creation process on server?

That I will need a custom script for the watermarking, as it´s not included with Calibre - that I know.

I was more asking for dynamic creation process of an ebook on our server and whether Calibre might be the right tool for that.

Most of Calibre's functionality is also available from a CLI.
As I said. What you want to script, was not intended, but might be doable via the CLI.

[AgeG]

Thanks theducks,

I had a first look at the CLI manual. Looks very promising.

I would have in mind the following process:

1.) After purchase ebook files get copied in a temp folder
2.) Watermarks gets imported/loaded/placed
3.) Ebook gets converted via Calibre CLI and saved in folder on server
4.) User gets download link

As the convesion seems to be present via CLI this might be working out.

Will talk to our developer about that.

If someone gots some experience with that or has another/better idea - any help is most welcome.

AgeG

[ilovejedd]

Originally Posted by AgeG

As the convesion seems to be present via CLI this might be working out.

Will talk to our developer about that.

If someone gots some experience with that or has another/better idea - any help is most welcome.

My suggestion, create a script to manually insert the watermark to an existing EPUB. This would be faster and less resource-intensive than doing an HTML/OEB/EPUB to EPUB conversion via Calibre.

Prepare your source EPUB file so it has a placeholder for where you want to insert the watermark. Then, just open the EPUB file using whatever language you're using for server side scripting (most should have native ZIP support and EPUB is basically a ZIP file with a different extension), edit the placeholder files to insert the user's personal information and serve the book to the client. Doing it this way would use less server resources and the script will probably take just milliseconds to complete. You don't even need to create temporary copies as everything could be handled via the script(s).

P.S.
There is, however, an advantage with doing this via Calibre CLI. With Calibre, you could output to different formats including MOBI (the Kindle likely has the biggest install base among all readers). Using the method I outlined above, you could only output EPUB.