It is a simple mixer on Python with OSD using Qt.
I wrote it because xfce have not same tool.
If you like it, continue this project, I finished.

Usage:
sosiska.py 50 # set volume to 50%
sosiska.py up 5 # increase volume for 5%
sosiska.py down 10 # decrease volume for 10%
sosiska.py --help # print usage