FOCUS Enhancements Bridge/Router MX-4DV - Manual (Page 165)

G L O S S A R Y
Some terms defined in this glossary might not appear in the body of the
User Guide.
A/A Roll
A term originating in the film world. Normally describes roll-
ing a single source into an effects device, such as the FOCUS
Enhancements MX-4 DV, and creating transitions between
the individual scenes.
A/B Roll
Variation of A/A Roll (described above). Normally describes
rolling two or more sources into an effects device, such as the
FOCUS Enhancements MX-4 DV, and creating transitions
between the various source images.
Betacam
An industry standard format that uses half-inch videotape run-
ning at high speed to produce high quality video. It is an
evolving standard. There are currently three versions in com-
mon use: Betacam, Betacam SP, and Digital Betacam.
Camcorder
Combination camera and video recorder in one device. Nor-
mally contains video recording heads as well as a video play-
back unit (that is, a mini-VCR).
Composite Video
The format used by televisions and laser disc players. Both
signals are combined into one signal, which is of lesser qual-
ity. Also see S-Video.
Counter
A relative indicator of tape position. On VCR/s that do not
support time code, the tape counter stores scene locations.
Because it is a relative indicator of tape position, it is subject
to drift. The same tape logged on one VCR and viewed on
another might report different counter locations for the same
scene.
Deck
A video cassette/tape player or recorder, also called a VCR or
VTR.
Digital Still Camera
A recording device for taking photographs and storing the
information in digital form. The device is similar to a 35mm
reflex lens camera that uses traditional film except that it
stores the image on a silicon chip. Images can then be down-
loaded to a computer system.
Drop Frame
A variation on the SMPTE time code format. It refers to a
scheme designed to compensate for the fact that NTSC actu-
ally runs at 29.97 fps. Normal Time Code (or, Non-Drop
Frame Time Code) is recorded and calculated based on 30 fps.
Because the actual number of frames per second is really
29.97, a discrepancy occurs causing a loss of slightly more
than three seconds each hour. Drop frame corrects for this
error by skipping two frames every minute, except on the
tenth minute.
Flying Erase Heads
Standard erase heads are mounted along the tape path in a
VCR. A flying erase head is built into the video head drum
just ahead of the video heads. It makes it possible to erase the
video each helical scan at a time resulting in clean video edits
with no rainbow effect. It is a requirement for high quality
video editing.
FPS
Frames Per Second. The number of picture frames that are
recorded or played during a one second period. Television
nominally uses 29.97 fps (NTSC) or 25 fps (PAL).
IR
InfraRed is one of several remote control protocols. It is a
one-way protocol that allows a device to send commands to
the VCR. Because this is a one-way communication, the VCR
cannot send tape location information back. VCR’s that offer
this limited method of control are suitable only as record
decks.
LTC
Longitudinal Time Code is an SMPTE-defined standard for
time code, normally recorded onto a linear audio track of a
VCR.
NTSC
National Television Standards Committee. A body that
defines television standards in the USA. NTSC is character-
ized by each frame being composed of 525 horizontal scan-
ning lines per frame, occurring at 30 frames per second. The
format is used in North America, Central America, Japan, and
parts of South America. (Also see PAL and SECAM.)
NVRAM
Non-Volatile Random Access Memory. MX-4 DV uses
NVRAM to store unit settings so that they are available when-
ever you power up the unit. Normal (that is, volatile) RAM
cannot store information once the power supply is turned off.
OSD
On Screen Display. A feature available on some consumer-
level VCR’s. When OSD is toggled ON, the VCR displays its
status information on the connected video monitor.