Thompson ViBE EM4000, User Manual

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Glossary
ViBE EM4000 — Release 1.10 247
User Manual — 46073586AB02
VANC Vertical Ancillary.
Ancillary packets located in the vertical blanking interval.
VBI Vertical Blanking Interval.
In analog video, the interval after the last displayed line of video in a field
and before the first displayed line of video in the next field, during which
a television receiver will synchronize vertically.
VBR Variable Bit-Rate.
VBR
is an encoding method that is designed to achieve a better video
quality vs. bitrate ratio than CBR (Constant Bit-Rate) encoding. This is
achieved by continuously changing the bit rate during the encoding
process depending on the picture complexity. Refer to
Statmux .
VBV Video Buffering Verifier
The video buffering verifier is a theoretical MPEG video buffer model used
to ensure that an encoded video stream can be correctly buffered and
played back at the decoder device.
VCT Virtual Channel Table (ATSC).
A VCT contains a list of all the channels that are or will be online, along
with their attributes. This table is critically important as it contains the set
of data that enables a receiver to tune and locate the service being
broadcast.
VGA Video Graphics Array (640x480 pixels).
VITC Vertical Interval Time Code.
VITC is Time-Code information inserted in the vertical blanking of the
video signal.
VITS Vertical Interval Test Signal.
VITS signals may be inserted in the lines of the vertical blanking interval to
permit on the air testing of video circuit functions and adjustments.
VLAN Virtual Local Area Network.
A local area network with a definition that maps workstations on some
other basis than geographic location (for example, by department, type of
user, or primary application). The virtual LAN controller can change or add
workstations and manage load balancing and bandwidth allocation more
easily than with a physical picture of the LAN. Network Management
System software keeps track of relating the virtual picture of the local area
network with the actual physical picture. VLANs are based on logical
instead of physical connections.
VPS Video Programming System.
VPS is an older system which helped video recorders in Germany to
automatically record TV broadcasts correctly. Since replaced with Program
Delivery Control (PDC).
Weighted prediction Allows an encoder to specify the use of a scaling and offset when
performing motion compensation, and providing a significant benefit in
performance in special cases, such as fade-to-black, fade-in, and
cross-fade transitions.