Files informations are written to the database after every file during the scan. So even if you abruptly stop the scan, what has already been scanned is not lost.
Of course Ubooquity will have to check the files names and modification date the next time a scan is launched, but it is very, very fast (the time consumming operations are the thumbnail extraction and generation as well as the metadata extraction when they exist).
As for the scan period, it does not really matter for the initial scan as a new scan won't be launched until the first one is finished.

Now you can launch multiple Ubooquity instances as long as:

• they are launched in different folders
• they run on different ports

But it would be interesting to understand why the scan fails at some point.
Do you see any error in the log file when the scan stops ?

Hi, sorry for the delay.
I have not been able to reproduce the problem.
Do you have any specific error in the log file ?

Two things to check:

• the log file: the port Ubooquity is using is logged when the server starts. It would be interesting to know which port (old one or new one is logged)
• the preferences.xml file: same thing

Also, be sure NOT to specify a port number on the command line when starting Ubooquity in UI mode (command line arguments are also written to the log file when the server starts or restarts, so you can check them there).

Were there some specific error in the log file (look for the name of the files which failed) ?

If you want, send me the files that don't work and I'll take a look.
tom "at" vaemendis.net

OPDS is not supposed to be used in browsers.
Firefox offers a basic representation of the OPDS XML file, but it's a lot let usable than the usual Ubooquity pages.

OPDS is a way to allow inter applications communication. Especially for mobile applications (cf Ubooquity 1.7.0 annoucement post on the site).

Here are a few clarifications on the matter.

All images Ubooquity provides, be they thumbnails or full pages, are jpeg generated by Ubooquity itself. So there won't be any browser compatibility problem (at not point does Ubooquity just "forward" the images, they are all read and resized).

Webp support requires a decoder. "webp-imageio" is not a candidate as it is only a wrapper around native code. Using it would require different version of Ubooquity depending on the platform you run it on (Linux, Windows, Mac OS...). Not an option.

I have howver found a free, full java Webp decoder. I will test it and add Webp support if it works well enough. That is if I find the time to do it. As you might have noticed, Ubooquity development has been even slower than before and I won't have much time to give it to in the coming months.