6© 2009 VBrick Systems, Inc.
Table 2. IWS Configurable Options
Optimizing MPEG-2 Performance
VBrick appliances are designed to accommodate a variety of configurations. Options such as
Hard Disk record and playback, and FTP file serving capability are fully meshed together,
supporting a diverse set of applications. VBrick unit's configuration choices enable the widest
range of features and capabilities and are designed to provide the user with a high degree of
flexibility. In some extreme cases, users can create configurations that exceed the normal
processing capacity of the unit causing it to not perform optimally. VBrick units provide
statistical counters and status variables indicating current device utilization and can even be
configured to report SNMP trap alarm conditions when these situations occur. Corrective
action usually involves the reduction of a video rate or disabling a channel, easily performed
via the IWS or CLI user interface. Under abnormal operating conditions, VBrick units
provide total system protection against any integral damage and guarantee management
connectivity via IWS or CLI.
In general, MPEG-2 video quality improves when video rate is increased. Significant video
quality improvements are noticeable when moving between 1.2 and 5 megabits per second
video rates. The video quality improvement becomes less noticeable when moving from
medium rates to higher video rates (from 5–9 Mbps.) with most of the improvement
occurring only during high motion video scenes. In essence, video quality is very subjective
and relates to other components such as the response of the human eye, the quality and
original content and signal, and the quality of the decoder and monitor. As a general rule, use
the lowest video rate that best suits the application.
Option Applicable Model
Network All VBrick models.
•Ethernet.
Billboard Only on models which have decoders.
Decoder Single or dual:
•Ethernet MPEG-2.
•Ethernet MPEG-4.
• SDI MPEG-2 (see SDI Configuration).
Encoder Single or dual:
•Ethernet MPEG-2.
• SDI MPEG-2 (see SDI Configuration).
Pump VBStar models only (see VBStar).
Recorder VBStar models only (see VBStar).
FTP File Transfer VBStar models only (see VBStar).
Conferencing Encoder and decoder combination models only.
Passthrough All VBrick models.
System All VBrick models.
Video on Demand Decoder models only.
Script Management All VBrick models.