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Video Production - Your Fast Track Guide to Producing Video |
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artifact
Distortion to a picture or a sound signal. With digital video, artifacts
can result from overloading the input device with too much signal, or
from excessive or improper compression.
bandwidth
(1) The frequency range of a video signal in MHz. (2) The amount of information
that can be carried by a signal path. Similar to the amount of water that
can be carried by a pipe of a specific diameter.
batch capture
The automated process of capturing clips in a list. A list of clips to
be batch captured.
bitmap
A graphic image comprised of individual pixels, each of which has a value
that define its relative brightness and color.
broadcast quality
A quality standard for composite video signals set by the NTSC and conforming
to FCC rules. If you plan to record video signal or videotape for broadcast,
it is important to note that devices providing NTSC signals do not necessarily
meet FCC broadcast standards.
camcorder
A combination camera and recording device that records continuous pictures
and generates a signal for display or recording.
capture card
Sometimes called a capture or video board, the logic card installed into
a computer and used to digitize video. Or, for video that is already digitized,
the device that simply transfers the file to the hard disk. Using a hardware
or software codec, the capture card also compresses video in and decompresses
video out for display on a television monitor.
chroma key
A video effect wherein a particular area of color is removed from one
video signal and replaced with a different signal. This effect is often
used during newscasts when a weather map is inserted behind a meteorologist
during a newscast
clip
A digitized or captured portion of video
codec
Contraction of compression/decompression algorithm; used to encode and
decode, or compress and decompress data, such as sound and video files.
Common codecs include those that convert analog video signals to
compressed digital video files (e.g., MPEG), or that convert analog sound
signals into digital sound files (e.g., RealAudio®)
compositing
The combining of two or more images into a single frame or display.
compression
The translation of audio or video data into a format that requires less
storage space than the original data.
data rate
The amount of data moved over a period of time, such as 10MB per second.
Often used to describe a hard drive's ability to retrieve and deliver
information.
deinterlace
To remove artifacts that result from the nature of two-fields-per-frame
(interlaced) video.
digital
Information in the form of binary data. Computers are digital machines
that use a binary system. That is, at their most basic level, computers
can distinguish between just two values, 0 and 1 (i.e., off and on). There
is no simple way to represent all the values in between, such as 0.25.
All data that a computer processes must be digital, encoded as a series
of zeros and ones. Digital representations are approximations of analog
events. They are useful because they are relatively easy to store and
manipulate electronically.
digitize
To convert analog video, audio, or both to digital form.
Digital video (DV)
A video signal made of binary digits. To store and manipulate analog video
on a computer workstation, it must be converted to digital video.
DV
Abbreviation for digital video. DV can also denote the type of compression
used by DV systems or a format that incorporates DV compression. The DV
designation is also used to for a special type of tape cartridge used
in DV camcorders and DV tape decks.
dub
To record or mix pre-recorded audio or video from one or more sources
to a another source to create a single recording.
DVD
Abbreviation for digital versatile disc. DVDs look like CDs, but have
a much larger storage capacity - more than enough for a feature-length
film compressed with MPEG-2. DVDs require special hardware for playback.
DVD-ROM
A digital storage medium based on DVD that may eventually replace CD-ROM.
DVD-Video
An MPEG-based digital storage medium used for pre-recorded movies. DVD-Video
may eventually replace VHS.
FireWire
The Apple Computer trade name for IEEE 1394.
fps
Abbreviation for frames per second; the standard for measuring the rate
of video playback speed. A rate of 30 fps is considered real-time speed
and a rate of 24 fps is considered animation speed. At 12-15 fps, the
human eye can detect individual frames causing video to appear jerky.
frame
A single still image in a sequence of images that, when displayed in rapid
succession, creates the illusion of motion. The more frames per second
(fps), the smoother the motion appears.
frame rate
The number of frames per second displayed during playback
generation loss
The incremental reduction in image or sound quality or both due to repeated
copying of analog video or audio information and noise introduced during
transmission. Generation loss does not occur when copying digital video
unless it is repeatedly compressed and decompressed
i.LINK
The Sony trade name for IEEE 1394.
IEEE
Abbreviation for the Institute of Electrical and Electronic Engineers;
the organization that sets many of the electronic-industry standards.
IEEE 1394
The interface standard that enables direct transfer of DV between devices,
such as a DV camcorder and a computer. IEEE 1394 also describes the cables
and connectors utilizing this standard.
keyframing
The process of creating an animated clip wherein by selecting a beginning
image and an ending image the software automatically generates the frames
in between.
letterbox
The aspect ration of motion pictures is wider than those of standard televisions.
To preserve the original aspect ratio of a motion picture, a motion picture
includes black bars at the top and bottom of the screen when played on
television.
lossy
A compression scheme or other process, such as duplication, that causes
degradation of signal fidelity. Lossy algorithms compress digital data
by eliminating the data least sensitive to the human eye, and offer the
highest compression rates available.
lossless
A compression scheme or other process, such as duplication, that does
not affect signal fidelity, such as the transfer of DV via an IEEE 1394
connection.
MPEG
Motion Pictures Expert Group of the International Organization for Standardization
(ISO) that has defined multiple standards for compressing audio and video
sequences. MPEG is also referred to as both a type of compression and
a video format.
MPEG-1
The international compression standard for the conversion of analog motion
video to digital motion video that includes both video and audio data.
MPEG meets the needs CD-ROM and video-on-demand applications. Actual compression
over uncompressed digital video is about 100:1. MPEG-1 was initially designed
to deliver near-broadcast quality video through a standard speed CD-ROM.
Playback of MPEG-1 video requires either a software decoder coupled with
a high-end computer or a hardware decoder.
MPEG-2
MPEG-2 is an extension of the MPEG-1 compression standard designed to
meet the requirements of television broadcast studios. MPEG-2 is the broadcast
quality video found on DVDs and requires a hardware decoder (e.g., a DVD-ROM
player) for playback.
multimedia
The combining of different computer-based media—usually audio, text,
graphics, and animation—into a single presentation. Multimedia presentations
are typically played back directly from the computer.
non-linear editing
Random-access editing of video and audio on a computer, enabling edits
to be processed and reprocessed at any point in the timeline, at any time.
Traditional videotape editors are linear because they require editing
video sequentially, from beginning to end.
NTSC
(1) Abbreviation for the National Television Standards Committee that
standardized the NTSC color broadcasting system currently used in the
United States. (2) The video format standard defined by the NTSC, also
called composite because it combines all the video information, including
color, into a single signal. See NTSC composite.
off-line editing
A preliminary edit generally performed on an inexpensive editing system
using video tape copies of the original master tapes. Off-line editing
enables editors to make decisions and obtain approvals before making more
expensive on-line edits.
on-line editing
The final linear editing of the original master tapes to produce the finished
piece. An on-line edit suite generally includes all the necessary high-end
devices (e.g., a switcher, TBC, character generator, etc.).
overscan
(1) The portion of a television picture that extends beyond the normal
screen size. (2) The method for scanning a video image beyond the normal
viewing area of a screen. Contrast with underscan.
PAL
Phase-alternating line television standard used in most European and South
American countries. PAL uses an interlaced display with 50 fields per
second, 25 frames per second.
pixel
Contraction for picture element; the smallest computer display element
represented as a point with a specified color and intensity level. Graphics
programs generally create images with square pixels. NTSC and PAL video
pixels, however, are generally rectangular, which means graphics displayed
on a TV screen will be distorted (e.g., a circle will display as an ellipse)
unless the pixel aspect ratio of the graphics is adjusted to suit the
video.
post-production
The stage of a film or video project during which footage is edited and
assembled and effects, graphics, titles, and sound are added.
pre-production
The planning phase of a film or video project, usually completed prior
to production.
printing to tape
Outputting a digital video file for recording onto a videotape.
Print to Video
A feature of Adobe®
Premiere that enables you to play a
clip or the Timeline centered on a monitor. If the clip or Timeline is
smaller than the full screen, it will play alone or on a black background.
Print to Video is useful for previewing the program in the Timeline, for
viewing source clips or individual files, or for video playback because it
allows you to play a quarter screen video at full screen size. Some
capture cards do not support Print to Video.
production
The phase of a film or video project that involves shooting or recording
raw footage.
QuickTime
Apple® Computer's multi-platform, industry-standard, multimedia software
architecture. QuickTime is used by software developers, hardware manufacturers,
and content creators to author and publish synchronized graphics, sound,
video, text, music, virtual reality, and 3-D media. QuickTime 4 includes
support for Real Time Streaming Protocol (RTSP).
raw footage
Original, unedited film or video footage that has not been modified.
RealMedia®
Architecture designed specifically for the Web, featuring multimedia streaming
and low data-rate compression options. RealMedia® works with or without
a RealMedia server.
real-time
In computing, an operating mode under which data is received, processed,
and the results returned quickly enough to seem instantaneous. In video,
real-time also refers to effects and transitions that happen without interrupting
rendering.
resolution
(1) The amount of information in each frame of video, normally represented
by the number of horizontal pixels times the number of vertical pixels
(e.g., 640 x 480). (2) The measure of the extent to which detail is distinguishable
on a TV screen. (Generally referred to as "horizontal resolution"
for video images.) Resolution is determined by the limit to which the
lines of a test pattern are distinguished by the naked eye. The broader
frequency band of a video signal allows for higher resolution.
RGB
Abbreviation for red, green, blue; the three primary colors of the additive
color system, such as that used to display color on a computer monitor
or television screen.
S-VHS
Short for Super VHS, a much improved version of VHS (compatible with VHS).
S-video
Short for Super-video, a technology used for transmitting video signals
over a cable by dividing the video information into two separate signals:
one for luminance and one for chrominance. (S-Video is synonymous with
Y/C video). S-video is a consumer form of component video used primarily
with Hi8 and S-VHS equipment.
safe title area
The area that comprises the 80 percent of the TV screen measured from
the center of the screen outward in all directions. The safe title area
is the area within which title credits—no matter how poorly adjusted
a monitor or receiver may be—are legible.
still frame
A single frame of video repeated so it appears to have no motion.
streaming
The process of sending video over the Web or other networks to allow playback
on the desktop as the video is received, rather than requiring the entire
file to be downloaded prior to playback.
striping
Preparing a tape for editing by recording continuous control track, timecode,
and a video signal (e.g., black). Also known as black stripe.
switcher
The device that serves as a central router and mixer of video source material
in an on-line suite, and performs effects (e.g., fades and dissolves)
as well as switching incoming channels. Also known as a video switcher
temporal compression
A compression method that reduces the data contained within a single video
frame by identifying similar areas between individual frames and eliminating
the redundancy.
three-point editing
In Adobe®
Premiere, the feature that enables editors to insert a clip into an
existing program where only three of the four in and out points of the
clip to be inserted, and the portion of the program where the clip is
being inserted, are known.
temporal compression
A compression method that reduces the data contained within a single video
frame by identifying similar areas between individual frames and eliminating
the redundancy.
three-point editing
In Adobe®
Premiere, the feature that enables editors to insert a clip into an
existing program where only three of the four in and out points of the
clip to be inserted, and the portion of the program where the clip is
being inserted, are known.
timecode
Generally refers to the industry standard of STPME timecode, which is
formatted as four numbers separated by colons (e.g., 21:52:31:20). The
numbers represent hours, minutes, seconds, and frames, and are added to
video to enable precise editing. Since color video runs at 29.97 fps instead
of 30 fps, two kinds of timecode have evolved: drop-frame and non-drop-frame.
Non-drop-frame timecode is formatted as four numbers separated by semicolons
(e.g., 21;52;31;20).
timeline
The graphical representation of program length onto which video, audio,
and graphic clips are arranged.
title generator
A black-and-white camera used for shooting titles that are electronically
superimposed onto the video picture during shooting or editing. A more
sophisticated device know as a character generator (CG) can generate titles
directly.
transition
The change from one video clip to another.
uncompressed video
Raw digitized video displayed or stored in its native size