I was just wondering if the java Webcam Capture API was safe. The reason I'm asking this, is because it contains .dll files for the webcam.
I might sound crazy, but It's the first time, I'm using a public API. And I have a large fear of virus, trojans, and key loggers.
Also is this the right website to find it http://webcam-capture.sarxos.pl/?
We cannot tell you. This kind of question is unanswerable in general if you want a clear objective "yes".
If you want a definite, objective answer, you should pay a security expert to audit the code for you. That will only give you an answer for a specific version of the code obtained from a specific place, and used on specific platforms. And its reliability will depend on the expertise of the expert, and how much time he / she spent on the audit and related research.
Any answer that is not based on an audit is only (really) just an opinion. It could be proven incorrect (in hindsight) when someone finds and discloses a flaw.
However ... since this is open source code, you could (in theory) conduct an audit yourself.
The flip-side is that if you (pay for) some proprietary software, you might have legal recourse if there were security or privacy flaws. But you need to read the license agreement carefully before agreeing, because a typical click-through software license agreement takes away your right to sue for damages, etcetera.