I have the same problem, trying to install jitsi from sid, using
apt-pinning, the system is jessie otherwise.
My /etc/apt/preferences.d/98jitsi file is as follows:
```
Package: jitsi
Pin: release a=unstable
Pin-Priority: 1000
Package: *
Pin: release a=jessie
Pin-Priority: 500
Package: *
Pin: release a=unstable
Pin-Priority: 400
Package: *
Pin: release a=experimental
Pin-Priority: 300
```
The error I get when using sudo apt-get -t unstable install jitsi is:
```
The following packages have unmet dependencies:
jitsi : Depends: libjitsi (>= 415-0) but it is not installable
Depends: libjitsi-jni (>= 415-0) but it is not installable
E: Unable to correct problems, you have held broken packages.
```
-Milos
