somagic debian source packages from https://code.google.com/p/easycap-somagic-linux/
on rpi needs jessie repository
sudo apt-get install -t jessie devscripts debhelper
sudo apt-get install -t jessie libgcrypt11-dev libusb-1.0-0-dev
debuild -us -uc
# for cleaning
fakeroot debian/rules clean
usbsoop 1.8 usbsnoop2libusb.pl
usbsnoop.txt - manual