QNAP Security VioStor NVR (Version: 4.1.1) - Manual (Page 171)

171
6.6.2.2 User defined Multi-stream
In the past, users of digital surveillance systems were forced to make a tradeoff
between the video quality of a camera stream and requested bandwidth. The same camera
stream was used for both live view and recording, and more bandwidth was required if a
high quality camera stream was selected. Fortunately, with the introduction of
multi-stream technology, users now can choose the main stream for recording files and the
sub stream for live view.
The multi-stream technology was already supported by VioStor NVR before firmware
v4.1.0. However, stream properties such as resolution, frame rate, and compression
mechanism were all fixed and could not be changed by users.