BUSS 213
Multimedia in Organisations
Lecture 5
Media 3: Temporal MediaSound and Video
Clarke, R. J (2001) L213-05:
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Notices (1)
General
 Lab 5 is transferred to Lab 6 effective from today
(24/8/01) till the end of session (so that we can
make use of machines with more memory and
usable sound facilities)
 this week tutorial sheet is available on this site for
use in the laboratory (open up WORD or simply
print it out)
 Assignment 1 is due today
 BUSS213 is supported by a website, where you
can find out the latest Notices and get Lecture
Notes, Tutorial Sheets, Assignments etc
www.uow.edu.au/~rclarke/buss213/buss213.htm
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Notices (2)
Assignment 2
 Assignment 2 will be available from the BUSS213
Intranet on Monday (you have the week end to catch
your breath):
 it involves creating a Multimedia Presentation for a
Concept, Service, Place or Product.
 use internet to gather material (which must be credited).
You write the text, design and implement the presentation.
 the best movies will go into a gallery on the BUSS213
website. This assignment will be a Director project in
Version 5 Academic only!
 you must send me your topic in an e-mail called A2-213-01
only this time you have one (1) week to send this email
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Agenda (1)
 in this third lecture on media we consider various
topics relevant to sounds and images- temporal media
 Again the rationale for having lectures on separate
types of media is that it is necessary to understand
individual media in detail before we consider how to
combine them
 this is such a huge topic that the contents of this
lecture are very selective!
 we will not consider in this lecture different types of
bradcast video standards, integrating computers and
television, or recording formats- read the text and yes it
is examinable
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Agenda (2)
Topics in this Lecture & Related Readings
 we will discuss:
 Video
 Related Readings
 Video Basics
 Shooting and Editing Video
 Digital Video
 we will not discuss audiowe simply don’t have the
time- but it is important that
you understand it, read
about:
 Vaughan (1998) Chapter
10: Sound, 241-282 and
Chapter 13: Video 339368
 as with all specified
reading- these are
examinable material
 Audio
 Audio Basics
 Digital Audio
 Production Aspects
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Video Basics
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Video Basics
Additive and Subtractive Colour Schemes
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Analog Camera Technologies
RGB colour video camera system
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Analog Camera Technologies
Single sensor colour video camera system
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Video Basics
Analog Artifacts
 Standard analogue video contains many problemsone of these is a set of problems called artifacts
 if you are intending to create digital multimedia and
you are using analog video sources then artifacts
effect the quality of the result and can adversely
effect compression of the final digital form
 Various types of artifact include: Noise, RF
Interference, Loss of high frequencies, smear,
streaking, colour fringing, colour balance errors,
colour saturation errors, flag waving, and jitter
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Analog Artifacts
Noise & RF Interference
(simulated noise)
 Noise (shown on the left): the
most common form of noise is
called ‘snow’ as seen on your
TV- it is specked appearance- if
it is uniformly distributed over
the full bandwidth of the video
signal then it is called white
noise (or flat noise)
 RF Interference: Various kind
of coherent (not random)
interferences will depend on
the exact frequency
relationship they have to the
scanning frequencies
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Analog Artifacts
Loss of high frequencies
 in composite colour television, the first
effect of loss of high frequencies is that
colour saturation- vividness of the colouris reduced or colour is completely lost
 Severe loss of high frequencies will
noticeably affect the sharpness of vertical
edges in images
 In RGB systems loss of high frequencies
affects sharpness although not uniformly
in all separate channels
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Analog Artifacts
Smear
 shows up as picture
information which is
smeared to the right
(usually) it is cause by a
loss of amplitude or a
phase shift at frequencies
near or so what above the
horizontal line frequency
 tube based camera have
a high peaker adjustment
which can cause this
distortion if not correctly
set
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Analog Artifacts
Streaking
 Streaking is present
when a bright object in
the image causes a
shifting of brightness all
the way across the image
at the vertical location of
the bright object
 Usually caused by video
information which gets
into the blanking interval
and interferes with
circuits in the video
equipment
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Analog Artifacts
Colour Fringing
 when edges in the pictures have colours
not present in the originals scenes- the
principal cause of which is registration
errors in cameras- generally the colour
fringing occurs through the image
 other possible causes include distortions
introduced during recording- in which
case the unwanted colours occur only in
vertical edges
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Analog Artifacts
Colour Balance Errors
 In RGBs system, the most likely colour errors are
caused by the video levels not being the same in each
of the three channels- this type of error originates at
the camera
 Colour balance errors show up as an ‘unnatural’
constant colour over the entire image independent of
which colours are used in a scene- sometimes this is
called a cast (not to be confused with Director)
 Possibly the operator did not go through a colour
balance procedure (for those camera that
automatically white balance- almost all of them- this
procedure involves either pointing the camera at a flat
white surface or using a white opaque lens cap)
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Analog Artifacts
Colour Saturation Errors
 affects any composite video systemsthose where three distinct video signals
(Red Green Blue or RGB) are encoded into
a ‘composite’ signal in order to be
distributed onto a single cable
 colour saturation errors can most
commonly be caused by an incorrect high
frequency response in the composite
signal which effects the amplitude of the
colour sub-carrier
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Analog Artifacts
Flag Waving
 In low cost recorders there can be a problem of
synchronisation instability at the top of the
picture called flag waving
 Shows up as vertical edges at the top of the
screen moving left to right from their correct
position
 Caused when the video playback head has to
leave the tape at one edge and come back onto
the tape at the other edge (helical scanning
means that video information is written in
diagonal strips along the video tape)- if the tape
is not tensioned correctly flag waving occurs
although video recorders can have a skew control
which adjusts tape tension
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Analog Artifacts
Jitter
 with jitter, the entire picture shows a
random motion from left to right caused
by time base errors from the video
recorder
 in video recorders the smoothness of the
mechanical motion of the recorders head drum
is very crucial to reproducing a stable picture
 Higher priced recorders use a Time Base
Corrector (TBC) to correct this problem
 Occasionally jitter effects are caused by other
kinds of defects or interferences getting into
the synchronizing signals or circuits
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Digital Video
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Analog to Digital Conversion
24 bits per pixel (bpp)
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Image Digitisation
Effect of the Numbers of Pixels
512 x 480 pixels
128 x 120 pixels
 the eye is tolerant to
reducing the numbers
of pixels in an image
 the original 520 x 480
image is clear, but
making the number of
pixels to 128 x 120
makes the image fuzzy
but still recognisable
with only 1/16 the size
 at 64 x 60 pixels the
smallest image size has
a very grainy look
64 x 60 pixels
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Image Digitisation
Effect of Bits/Pixel
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Image Digitisation
Text Anti-aliasing
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Digital Video
 Dealing with digital video only is the
ultimate in video processing, however…
 …it is not yet common place to have
digital video cameras, and so…
 …the current state of the art is that you
typically record using analog video (in the
so-called analog domain) but complete all
other stages are completed digitally (in the
so-called digital domain) including editing
and post-production (cleaning up the
images, colour matching, special effects)
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Digital Video
Analog Broadcast Cameras are very good
 in fact, our experience with using side-by-side
comparisons (sometimes referred to as AB
comparisons) is that broadcast quality analog video
cameras can provide ‘better looking’ video in the same
conditions as ‘pro-sumer grade’ digital video cameras
 BetaCams (analog broadcast quality cameras) can be calibrated
to work in low light levels- in dark environments this means that
camera can distinguish between different levels of black- this is
more than just an issue of sensitivity its about the quality of
black- it looks ‘softer’ or warmer
 Digital Video Cameras can also reach into these dark levels but
they appear to flatten out or equalise the differences- the effect
is harsh and ‘flat’- more like watching cartoons- these effects
are subtle but you can see them if you look!
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Digital Video
Converting from Analog Video
 if you have analog video:
 recorded on a VCR at home, sourced from
broadcasts or from your own analog video camerasthis will need to be converted to digital information
 the process of conversion is called video digitisation
(or simply digitising) and the equipment used to do it
is referred to as video digitiser (or simply digitiser)
 with digitisers you pay for good quality you want to
be able to sample the video stream at least four
times higher than the frame rate- that is really fast
because video is made up of 25 frames a second
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Digital Video
Playback- Architecture
 the resulting digital video clip can be
stored as data on a hard disk, CD-ROM,
DVD, or other mass-storage device
without the use of other digital equipment
 the playback is provided by software
architectures:
 Microsoft’s Active Movie for Windows
(previously Video for Windows)
 Apple’s QuickTime
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Digital Video
Playback- Architecture
 we will briefly describe QuickTime- no serious
attempt at commercial multimedia system would
use anything else other than this product
 the authoring or development environment is only
available on Apple systems,
 this might seem to be a problem but in fact for a very
long time Apple systems have been the first and only
choice when considering development platforms
 it was only with the release of NT and 2000 than many of
the major multimedia development packages became
available to IBM PC users (eg. Adobe Suite products etc)
 QuickTime clips can be played on any platform and they
can be streamed on the Internet
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Shooting Video
Static & Dynamic Composition
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Shooting Video
Layout or Static Composition
 in this set of slides we will consider some
of the conventions used in the layout or
composition of a single image- so this
discussion applies equally to photography
and animation as it does for videography
 the term layout- or static compositionrefers to or the organisation of static
components like background elements,
props, position of actors or characters, and
camera viewpoint etc.
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Shooting Video
Semiotics of the Frame (1)
 the discipline of semiotics concerns itself with
understanding meanings
 in traditional and digital forms of animation,
photography, cinematography and videography,
placing a frame is a semiotic act because you are
selecting some visual elements and excluding
others
 the camera operator does not facilitate your
interpretation of the images rather the camera
operator mediates your interpretation
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Shooting Video
Semiotics of the Frame (2)
 an excluded elements in a scene literally does not
exist for the audience …
 … while the audience is confronted with only
those visual elements of the scene which the
camera operator considers relevant
 skillful camera work involves the camera
technician continuously deciding which elements
to include in the frame and…
 … anticipates the effect of these on the
audience’s interpretation of the scene
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Shooting Video
Rules of Composition (1)- Centres of Interest
 Composition refers to the relationship between the main subject –
the person or object of interest – within the frame
 it affects our perceptions of the scene and how the audience will
view and receive the worlds constructed for us by the camera
operator
 the rule of thirds (below) avoids compositions where all the
elements are perfectly balanced (symmetrical balance), applied to
the frame this rule produces four so-called centres of interest
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Shooting Video
Rules of Composition (2)
 Fill the whole screen with the
most important and significant
subject matter
 Empty space is wasted space
 Avoid tilted horizontal and vertical
lines
 Movement or bright lights in the
background are distracting
 If the background proves
problematic during shooting, it
will be worse for your audience.
Move the camera or the subject
before taping
 When shooting people, place the
subject’s eyes one-third down
from the top of the frame matter
the type of shot
 Action or line of sight towards
frame right should be positioned
frame left and vice versa for
‘nose room’
 Create illusion of depth by
having objects in foreground,
middle ground and background
 Always zoom in to full telephoto
to adjust focus
 Allow for image cut-off around
frame edges. Keep the important
parts of the image towards frame
centre
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Shooting Video
Rules of Composition (3)- Horizon Line
Scenes shot outdoors or in a
large room need a horizon line
where the ‘sky’ meets the ‘floor’
the horizon line should not be in
the middle of the frame which
results in an awkward layout
for the objects in the scene
 Most scenes should use a
1/3rd ground, 2/3rd sky
layout which allows propos
and backdrop details to be
seen while allowing apace
for characters to remain the
central attraction (left)
 Occasionally the 2/3rd
ground, 1/3rd sky rule is
used which is the same as
tilting the camera down- its
effect is to add a sense of
dramatic urgency so don’t
overdo it (right)
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Shooting Video
Long, Mid, Close-up & Extreme Close-ups
 Long Shot (LS)- the establishing  Close-Up (CU)- reaction shot
Shot
 often focuses entirely on the
 is the shot of the subject/s taken
from a distance away in order to
show the subject/s relation to
their physical surroundings
 Mid Shot (MS)- the action shot
 the shot used to show any
action occurring
 the subject is still seen in
relation to their surroundings,
yet there is still enough space in
the frame to show dialogue or
other interactions between
characters
subjects face and their face
only
 used to convey emotion and
are centred on the subject
 Extreme Close-Up (ECU)- the
emotion shot
 crop the top of the head and
chin and focus on the eyes
and mouth
 as with CU’s, ECU’s convey
emotion and are centred
entirely on the subject
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Shooting Video
Long, Mid, Close-up & Extreme Close-ups
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Shooting Video
Shot Framing- One Subject Scene
 the example on the right is correct- it conforms to the rules
of composition- centres of interest described earlier
 avoid the symmetrical balance of the middle example
 avoid cramping the subject’s face up against the frame on
the left hand example
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Shooting Video
Shot Framing- Two Subject Framing
 the layout of the upper
left frame is often
used by amateurs
 upper right hand
frame is more
interesting
 however shots can
and should be varied
like those used in the
lower frames
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Shooting Video
Poor Composition- Ambiguous Lines
 a number of problems that can result from
poor composition are shown below
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Shooting Video
Staging or Dynamic Composition
 staging refers to dynamic effects like character
movement and camera movement (including pans
and zooms)
 come is a number of varieties:
 Zoom in/out: not a true move but a lens change from wide
angle (LS) to telephoto (CU)
 Pan and tilt: pans move the camera horizontally (side to
side), tilt moves the camera vertically
 Track: you move the entire camera to follow a moving
subject
 Truck: the subject is stationary but the camera moves
 Dolly: moves the camera towards (dolly in) or away (dolly
out) from the subject- a dolly shot changes visual
perspective because the camera is moving through the
scene
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Shooting Video
Staging or Dynamic Composition
 How fast should dynamic movement beno faster than the movement of the
second hand on you watch
 Any faster and the action will blur, and this
will likely make your viewer disoriented at
best and nauseous at worse
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Video Technologies
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Video Production Workflow
Stages and Typical Technologies
On-line
Off-line
Camera Work
Digital
Editing
Shooting
Analogue or Digital
Premier
Final Cut Pro
Effect
Transitions
Titling
PostProduction
After Effects
Formatting
Compressing
Delivery
Compression
Media Cleaner Pro
Sorenson
See also detail on Digital Editing Workflow in Lecture BUSS213-12a
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