What is `libsane-v4l.so.1` and how do I get it? Trying to fix a scanner problem (Brother DCP-110c scanner not working in Mint 18.1), and following this post that says to use export SANE_DEBUG_DLL=128 scanimage -L in order to look for errors of the form `No such file or directory` and copy the specified file at the specified location, I only got these errors: [dll] load: trying to load `/usr/lib/x86_64-linux-gnu/sane/libsane-v4l.so.1' [dll] load: couldn't open `/usr/lib/x86_64-linux-gnu/sane/libsane-v4l.so.1' (No such file or directory) [dll] load: trying to load `/usr/lib/sane/libsane-v4l.so.1' [dll] load: couldn't open `/usr/lib/sane/libsane-v4l.so.1' (No such file or directory) [dll] load: couldn't find backend `v4l' (No such file or directory) But these files seem absent (tested with `locate`)...

Those errors simply mean that `scanimage` tried to load the `v4l` backend, but failed. That’s not particularly surprising, because the `v4l` backend isn’t well supported nowadays (if at all) — it was designed for the old V4L kernel API, and as far as I’m aware hasn’t been updated to the current API (V4L2). On Debian derivatives (including Mint), it’s disabled.

In any case, none of that matters for your scanner: the V4L backend allows video input devices such as webcams to be used as scanners. It’s irrelevant for your printer.