Capture Devices, Video Encoding Standards and post-production techniques B.Sc. (Hons) Multimedia...
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Capture Devices, Video Encoding Standards and post-production techniques B.Sc. (Hons) Multimedia Computing Media Technologies Video Capture and Editing
Capture Devices, Video Encoding Standards and post-production techniques B.Sc. (Hons) Multimedia ComputingMedia Technologies Video Capture and Editing
Capture Devices PCI Card (PC) FireWire port on Mac( Developed
by Apple) & PC USB Port Video Camera Web Camera
Slide 4
Connectivity SCART Plugs and Sockets Phono Leads (RCA) Video in
Audio in left Audio in right
Slide 5
Connectivity S-VHS Video (Yellow) Audio Right (Red) Audio Left
(White)
Slide 6
The Serial Digital Interface Firewire Originally developed by
Apple as the IEE1394 Serial Digital Interface Referred to as
FireWire Simple and highly efficient method of not only
transferring digital signals between devices Most Camcorders have
DVout which can be connected to computer Firewire Port via
appropriate lead Two connector sizes, four pin - Camcorder, and six
pin - computer
Slide 7
The Serial Digital Interface Firewire Connection between
computer and camcorder enables users to control the camcorder
playback Where suitably equipped DV-in camcorders are present -
recording functions using the on-screen controls of the appropriate
program
Slide 8
Compression & Decompression CODECS Need CODEC
(Compression-Decompression; more recently, Coder-Decoder) on system
to play movie or extract compressed data to load into an editing
application (Premiere, etc). Some CODECS not well-supported across
platforms MPEG-X (X=1,2,3,4 etc.) is best for multimedia Sorenson
via Flash CS4 best solution for Flash- based work
Slide 9
What is a CODEC? (adapted from Wikipedia) Video is basically a
three-dimensional array of colour pixels. Two dimensions serve as
spatial (horizontal and vertical) directions of the moving
pictures, and one dimension represents the time domain. A data
frame is a set of all pixels that correspond to a single time
moment. Basically, a frame is the same as a still picture. Video
data contains spatial and temporal redundancy. Similarities can
thus be encoded by merely registering differences within a frame
(spatial), and/or between frames (temporal). Spatial encoding is
performed by taking advantage of the fact that the human eye is
unable to distinguish small differences in color as easily as it
can perceive changes in brightness, so that very similar areas of
color can be "averaged out" in a similar way to jpeg images. With
temporal compression only the changes from one frame to the next
are encoded as often a large number of the pixels will be the same
on a series of frames. Lossy compression results in far higher
compression ratios at an acceptable level of quality.
Slide 10
What is a CODEC? (2) One of the most powerful techniques for
compressing video is interframe compression. Interframe compression
uses one or more earlier or later frames in a sequence to compress
the current frame, while intraframe compression uses only the
current frame, which is effectively image compression. The most
commonly used method works by comparing each frame in the video
with the previous one. If the frame contains areas where nothing
has moved, the system simply issues a short command that copies
that part of the previous frame, bit-for-bit, into the next one. If
sections of the frame move in a simple manner, the compressor emits
a (slightly longer) command that tells the decompresser to shift,
rotate, lighten, or darken the copy a longer command, but still
much shorter than intraframe compression. Interframe compression
works well for programs that will simply be played back by the
viewer, but can cause problems if the video sequence needs to be
edited. Since interframe compression copies data from one frame to
another, if the original frame is simply cut out (or lost in
transmission), the following frames cannot be reconstructed
properly. Some video formats, such as DV, compress each frame
independently using intraframe compression. Making 'cuts' in
intraframe-compressed video is almost as easy as editing
uncompressed video one finds the beginning and ending of each
frame, and simply copies bit-for- bit each frame that one wants to
keep, and discards the frames one doesn't want.
Slide 11
CODECs Further reading about CODECs...about CODECs
http://www.animemusicvideos.org/guides/avtech/video 3.htm
http://videoproductiontips.com/video-production/digital-
video-file-formats-explained/
Slide 12
Export Formats Cinepac (Radius) MPEG Sorenson Spark Video for
Windows (Indeo) File types: avi (Windows) mpg. (MPEG) Mov
(Quicktime)
Slide 13
Common video file formats (Container formats) AVI - "Audio
Video Interlace" - Introduced in 1992 by Microsoft, supports
multiple steaming audio and video feeds. MOV - QuickTime Movie File
- Released in 1991, popular Apple format that supports live
streaming. RM - "RealMedia" - Multimedia format by RealNetworks
which is mostly used to watch streaming content over the web. 3GP -
Mobile Phone Format - Developed by the Third Generation Partnership
Project (3GPP), it is a format used for recording and viewing on
most modern cell phones. WMV - "Windows Media Video" - Approved in
2006, WMV is a codec that has seen wide-scale adoption in not only
streaming web content, but physical media such as HD DVD and
Blu-ray discs as well. MPG/MPEG - Developed by the "Moving Pictures
Experts Group," this format has gone through several revisions -
the first of which being MPEG-1, a compression standard that is the
most widely used in the world. MP4 - "MPEG-4 Part 14" - Based on
Apple's MOV container, this format allows for subtitles as well as
some MPEG features
Slide 14
Sorensen Spark (Wikipedia) As Apple began to move away from
proprietary codecs with its embrace of MPEG-4, Sorenson Media next
licensed a new video codec to Macromedia (later Adobe) as Sorenson
Spark (Sorenson H.263), released with Macromedia Flash 6/MX on
March 4, 2002. Sorenson Spark is the required video compression
format for Flash Player 6 and 7. Macromedia later tried to find a
better video codec. Starting with Flash Player 8 (released in
September 2005), the preferred video codec is VP6. The Sorenson
Spark can be still used in the Adobe Flash CS4 Professional (2008)
Flash Video.FLV files as one of three video compression formats
(alongside H.264 and On2 VP6). Sorenson Spark is an older codec but
it is also a widely available and compatible one, when used in
Flash Video. Sorensen Spark is considered an incomplete
implementation of H.263. The complete standard is known as
H.264.
Slide 15
Global Uptake of H.264 Brazils terrestrial broadcast service
uses H.264/AVC in ISDB-T Colombia announced in August 2008 the
adoption of the DVB-T broadcasting standard. Czech Republic O2, one
of DVB-T providers is broadcasting HD versions of TV channels CT1
and Nova experimentally in H.264/AVC. France's prime minister
announced the selection of H.264/AVC as a requirement for receivers
of HDTV and pay TV channels for digital terrestrial broadcast
television services (referred to as "TNT") in France in late 2004.
Lithuania, Estonia, Latvia and Slovenia are expected to use
H.264/AVC for all terrestrial digital television services. Hong
Kongs leading broadcaster, TVB, selected H.264 in for new digital
services there, including HDTV service, in the China DMB-T/H system
environment, starting from the end of 2007. Asia Television Limited
has joined this decision and uses H.264 for its new digital
services too (both broadcasters use MPEG-2 to encode the digital
simulcast of the existing analogue channels.) Hungary's DVB-T
service, MinDigTV, uses H.264 for encoding both SD and HD
transmissions, including simulcasts of analogue channels. Japan's
Mobile-segment terrestrial broadcast services of ISDB-T uses the
H.264/AVC codec, including major broadcasters such as NHK and Fuji
Television. Korea's Digital Multimedia Broadcast (DMB) service will
use H.264/AVC. Poland will test DVB-T transmissions (as of 2007 )
working reliably for several years) use MPEG-2, but commercial run
scheduled after 2010 will be MPEG-4 only. Portugal's DVB-T service
from Portugal Telecom will use H.264 for encoding both SD and HD
transmissions starting in 2009. New Zealand's Freeview service
launched its DVB-T transmissions in March 2008 using H.264/AVC.
Norway's NTV use H.264/AVC for its national DVB-T broadcasting
started October 2007 in central southern areas of Norway. Norway
are among the first to use MPEG-4/AVC exclusively in all its
terrestrial television broadcasts, finished by November 2008. The
analogue transponders will be switched off in 2009. Singapore's
first over-the-air HDTV channel, MediaCorp HD5, uses
H.264/AVC.
Slide 16
Deployment Compromises required to bring resource requirements
of video within capabilities of delivery medium ( e.g networks) and
low-end machines Reduce frame size - down sample to quarter frame
size - i.e. 320x240 pixels Reduce sample rate (12 or 15 fps is OK
for smooth motion, flicker not a problem on computer Reduce colour
depth
Slide 17
Support for Legacy Formats Betamax Video 8 VHS Director Final
Cut Video Transfer Interface Devices
Slide 18
Post Production Techniques B.Sc. (Hons) Multimedia
ComputingMedia Technologies Video Editing
Slide 19
Agenda Typical applications Post production process Popular
effects Examples Software applications B.Sc. (Hons) Multimedia
ComputingMedia Technologies
Slide 20
Typical Applications Broadcasting (sports, light entertainment)
Marketing (TV Ads) Film Industry Transfer from different formats
Recovery / renovating of archive material
Slide 21
Post Production Process Apply after footage is recorded and
edited (sequence) Apply effects ( adjust, modify, transform)
Transfer it to something you audience can see - whether it's a DVD,
the Web, or even a VHS tape. Resource intensive Time consuming
Sometimes the hardest part Professional equipment ( High Definition
(HD) Video) very expensive 10 000 +
Slide 22
Post Production Effects Adjustment / correction Brightness
Contrast Colour Balance Volume (gain, reverb, etc) Blur / Sharpen
Stylize ( emboss, texturize) 3D (depth of field, compositing)
Perspective ( skew, scale, stretch) Transitions (wipes, fades, etc)
Text ( titles, path text) B.Sc. (Hons) Multimedia ComputingMedia
Technologies
Slide 23
Post Production:Adjustment Original (left) and with variations
of Brightness & Contrast applied (centre and right) Brightness
and Contrast effect
Slide 24
Post Production: Adjustment Original (left) and with variations
of Color Balance applied (centre and right) Colour Balance
effect
Slide 25
Post Production:Blur & Sharpen Original (left) and with
variations of Directional Blur applied (centre and right)
Directional Blur effect
Slide 26
Original (left) and with variations of Channel Blur applied
(centre and right) Channel Blur effect Post Production:Blur &
Sharpen
Slide 27
Post Production: Distortion Original (left) and with variations
of Corner Pin applied (center and right) Corner Pin effect
Slide 28
Post Production: Noise Original Layer (left), Noise HLS
(center), and two applications of Noise HLS with low Saturation
values (right) HLS Noise effect
Slide 29
Post Production:Keying Original (left) and background layer
(centre) are combined using Color Difference Key (right). Colour
Key effect
Slide 30
Post Production: Image Control Original (left) and with
variations of Change Color applied (centre and right) Change Colour
effect
Slide 31
Post Production: Paint Two strokes in different colors painted
on the robot's antenna, using three variations of Vector Paint
Vector Paint effect
Slide 32
Post Production: Stylize Original (left), a layer used to
create texture (center), and the texture applied to background
layer (right) Texturize effect
Slide 33
Post Production: Transition Original (left) and with variations
of Block Dissolve applied (centre and right) Block Dissolve
effect
Slide 34
Post Production:Perspective Original (left) and with variations
of Basic 3D applied (centre and right) Basic 3D effect
Slide 35
Post Production: 3D Original (left) and with variations of
Depth of Field applied (centre and right) Depth of Field
effect
Slide 36
Post Production: 3D Original (left), with applied using the
near alien as the ID Selection (centre), and composited over a new
background (right) ID Matte effect
Slide 37
Post Production: 3D Original (left), Gradient Layer (centre),
and with Fog 3D applied (right) Fog effect
Slide 38
Post Production:Text Original (left) and with variations of
Path Text applied (centre and right) Path Text effect
Slide 39
Software Applications B.Sc. (Hons) Multimedia ComputingMedia
Technologies Adobe After Effects (PC) Final Cut Pro (Mac)
Slide 40
References B.Sc. (Hons) Multimedia ComputingMedia Technologies
Digital Multimedia 3rd Edition Chapman N. Chapman J. Wiley. 2010
http://www.cinepak.com/ http://www.mpeg.org/
http://www.sorenson.com/ http://www.adobe.com
http://www.digitalpostproduction.com
