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UNIT
5 |
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Multimedia System: An Introduction |
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Unit-05/Lecture-01 |
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What
is Multimedia?
(RGPV-2008,11,14) Multimedia can
have many definitions these include :( A computer system perspective), Multimedia means that computer
information can be represented through audio, video, and animation in
addition to traditional media (i.e., text, graphics/drawings, and images). General
Definition- A good general working definition for this module
is: Multimedia is the field concerned with the computer controlled
integration of text, graphics, drawings, still and moving images (Video),
animation, audio, and any other media where every type of information
can be represented, stored, transmitted and processed digitally. Multimedia
Application Definition- A Multimedia Application is an application which
uses a collection of multiple media sources e.g. text, graphics, images,
sound/audio, animation and/or video. Multimedia
Applications- Examples of Multimedia Applications include: _ World Wide Web _ Multimedia Authoring, e.g. Adobe/Macromedia
Director _ Hypermedia courseware _ Video-on-demand _ Interactive TV _ Computer Games _ Virtual reality _ Digital video editing and production systems _ Multimedia Database systems
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S.NO |
RGPV QUESTIONS |
Year |
Marks |
|
Q.1 |
What
is multimedia? Describe application areas and main properties of multimedia. |
RGPV-2008,11 |
10 |
|
Q.2 |
Explain briefly:- i)Multimedia Architecture |
RGPV-2014 |
7 |
|
UNIT
5 |
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Multimedia Hardware |
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Unit-05/Lecture-02 |
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Multimedia Hardware ·
Digital media devices ·
Analog media devices ·
General-purpose devices ·
Synchronization devices ·
Interaction devices ·
Multimedia platforms
General Purpose Devices- Devices
that process or deal with arbitrary media: ·
CD-ROM ·
Magnetic Disks ·
Oscilloscopes Interaction
device- · Keyboard · Mouse and joysticks · Electronic pens · 3D trackers · Gloves · Helmets & eye trackers Synchronization Devices- Simultaneous
presentation and manipulation of multiple media requires hardware assistance
to maintain proper timing.
Multimedia Platforms ·
Specially configured PCs and
workstations ·
MPC compliance Ψ Personal
computer Ψ Color
display Ψ Speaker
and microphone Ψ CD-ROM
drive Ψ Audio
and video digitizers Ψ Network
access |
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S.NO |
RGPV QUESTIONS |
Year |
Marks |
|
Q.1 |
Write short notes:- 1)Multimedia Applications,2)Sound cords |
RGPV 2014 |
14 |
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UNIT
5 |
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Multimedia
Systems |
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Unit-05/Lecture-03 |
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Multimedia
Systems
(RGPV-2009,11,14) A Multimedia System is a system
capable of processing multimedia data and applications. A Multimedia System is characterized
by the processing, storage, generation, manipulation and rendition of
Multimedia information. Characteristics
of a Multimedia System- A Multimedia system has four basic
characteristics: Ψ Multimedia systems must be computer controlled. Ψ Multimedia systems are integrated. Ψ The information they handle must be
represented digitally. Ψ The interface to the final presentation of
media is usually interactive. Challenges for
Multimedia Systems Ψ Distributed Networks Ψ Temporal relationship between data
Render different data at same time continuously.
Sequencing within the media Ψ playing frames in correct order/time frame in video
Synchronization-inter-media
scheduling. E.g. Video
and Audio Lip synchronization is clearly important for humans to watch
playback of video and audio and even animation and audio. Ever tried
watching an out of (lip) sync film for a long time? Key
Issues for Multimedia Systems The
key issues multimedia systems need to deal with here are:
How to represent and store temporal
information.
How to
strictly maintain the temporal relationships on play back/retrieval
What processes are involved in the above?
Data has to
represent digitally
AnalogDigital Conversion, Sampling etc.
Large Data
Requirements bandwidth, storage,
Data compression is usually mandatory. Desirable
Features for a Multimedia System- Given the
above challenges the following feature a desirable(if not a prerequisite) for a Multimedia System:
Very High Processing Power
needed to deal with large data processing and real time delivery of media.
Special hardware commonplace.
Multimedia Capable File System needed
to deliver real-time media e.g. Video/Audio Streaming.
Special Hardware/Software needed
e.g. RAID technology.
Data Representations File Formats that support multimedia
should be easy to handle yet allow for compression/decompression in real-time.
Efficient and High I/O input and
output to the file subsystem needs to be efficient and fast. Needs to allow
for real-time recording as well as playback of data.e.g. Direct to Disk
recording systems.
Special Operating System to allow
access to file system and process data efficiently and quickly. Needs to
support direct transfers to disk, real-time scheduling, fast interrupt
processing, I/O streaming etc.
Storage and Memory large
storage units (of the order of hundreds of Tb if not more) and large memory
(several Gb or more). Large Caches also required and high speed buses for
efficient management.
Network Support Client-server systems common
as distributed systems common.
Software Tools user friendly tools needed to
handle media, design and develop applications, deliver media Components of
a Multimedia System Now let us
consider the Components (Hardware and Software) required for a multimedia
system: Capture
devices
Video Camera, Video Recorder, Audio Microphone, Keyboards, mice, graphics
tablets, 3D input devices, tactile
sensors, VR devices. Digitizing Hardware Storage
Devices
Hard disks, CD-ROMs, DVD-ROM, etc Communication
Networks
Local Networks, Intranets, Internet, Multimedia or other special high speed
networks. Computer
Systems
Multimedia Desktop machines, Workstations, MPEG/VIDEO/DSP Hardware Display
Devices
CD-quality speakers, HDTV, SVGA, Hi-Res-monitors, Color printers etc. Multimedia
Applications- Examples of
Multimedia Applications include:
World Wide
Web
Hypermedia
courseware
Video
conferencing
Video-on-demand
Interactive
TV
Groupware
Home
shopping
Games
Virtual
reality
Digital
video editing and production systems Multimedia
media system consists the following: Multimedia Systems Design Ψ Analogue representation
vs digital representation Ψ Reconstruction Ψ File formats Ψ Compression Multimedia Elements Ψ Images Ψ Voice commands /
synthesis Ψ Audio / Video messages Ψ GIS Ψ Holography Ψ Fractal Multimedia
Applications Ψ Image processing and
recognition Ψ Electronic messaging Ψ Video conferencing Multimedia Architecture Ψ High resolution
graphics display Ψ Network architecture Data transfer, data duplication and
data replication Multimedia data interface Ψ File formats (e.g. RTF,
TIFF, MIDI, JPEG, MPEG, AVI) Ψ Compression of data Data Compression and Decompression Ψ Lossless vs lossy
compression Ψ 1-D compression Ψ 2-D compression Ψ JPEG standard Ψ MPEG coding methodology Analog Systems
vs Digital Systems Naturally audio and video signals are analog continuous
signals; they vary continuously in time as the amplitude, pressure, frequency
or phase of the speech, audio, or video signal varies. In general, an analog multimedia system is relatively simple
with less building blocks and fast response when comparing to a digital
system. An analog system is more sensitive to noise and less robust
than its digital counterpart. An analog media is more difficult in editing, indexing,
search and transmit among systems. Analog signals must be digitized by codec before computer
manipulation. Digital Representation of Multimedia Contents
Text or Data- Text or
data is a block of characters with each character represented by a fixed
number of binary digits knows as a codeword; ASCII code, Unicode, etc. The
sizes of text or data files are usually small.
Graphics-Graphics can be constructed by the composition of primitive objects
such as lines, circles, polygons, curves and splines.Each object is stored as
an equation and contains a number of parameters or attributes such as start
and end coordinates; shape; size; fill color; border color; shadow;
etc.Graphics file take up less space than image files. For data
visualization, illustration and modeling applications
Images- Continuous-tone images can be digitized into bitmaps, Resolution for print is measured in dots per inch (dpi), Resolution for screen is measured in pixels per inch (ppi), A digitized image can be represented as two-dimensional, matrix with individual picture elements. Each pixel is
represented by a fixed number of bits or N-bit quantization. 24-bit quantization provides 16,777,216 colors
per pixel. Dots are digitized in 1-bit quantization. |
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S.NO |
RGPV QUESTIONS |
Year |
Marks |
|
Q.1 |
Explain some of motion specification for computer
animation? |
RGPV 2014 |
7 |
|
Q.2 |
Give
a brief note on multimedia databases. |
RGPV 2014 |
7 |
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UNIT
5 |
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Data & File Format standards. RTF, TIFF, MIDI, JPEG, DIB, MPEG |
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Unit-05/Lecture-04 |
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Multimedia Data Interface Text and
Graphics File (RTF )- (RGPV-2009,11,13,14) The Rich Text Format (RTF) Specification provides a method of transferring encoding formatted text and graphics between different output devices, OS and applications.RTF uses the American National Standards Institute (ANSI),PC-8, Macintosh, or IBM PC character set to control the representation and formatting of a document, both on the screen and in print. RTF files begins with control word \rtfN; Where N is the major version number. An entire RTF file is consider a group and must be enclosed in braces. Current version is 1.7, hence The file will begin with
{\rtf1\ansi\ansicpg1252\....}
.. File Format Image file TIFF Ψ Tag image file format (TIFF) is
typically used to transfer graphics from one computer system to another. Ψ TIFF is an excellent method of
transporting images between file systems and software packages. Ψ It is supported by most
graphics packages and has a high resolutions that is typically used when
scanning images and Colures of up to 48 bits. Ψ It can use different
compression methods and different file formats, depending on the type of data
stored. TIFF file structure: TIFF files have a three-level hierarchy 1. A file header: It contains 8
bytes 2. One or more
IFDs (image file directories):These contain codes and their data (or pointers
to the data) 3. Data: The
data information
File Format JPEG- Joint
Photographic Expert Group (JPEG) is excellent compression techniques which
provide lossy compression. It is a compression technique for gray-scale or
color image and uses a combination of discrete cosine transform,
quantization, run-length and Huffman coding.JPEG operates differently in that
it stores changes in colour. As the eye is very sensitive to brightness
changes and less on color changes, then if these changes are similar to the
original then the eye perceives the recovered image as very similar to the
original. JPEG
files format: Ψ
The JPEG file normally complies with JFIF (JPEG
file interchange format) which is a defined standard file format for storing
a gray scale or YCbCr color image. Data within the JFIF
contains segments separated by a 2-byte marker. Ψ
This marker has a binary value of 1111 1111 (FFh)
followed by a defined marked field. If a 1111 1111 (FFh) bit field occurs anywhere within the file(and it isnt a marker), the stuffed 0000 0000 (00h) byte is inserted after it so that it cannot be read as a false markers. MPEG- Ψ ISO established the Moving Picture Expert Group with the mission to develop standards for the coded representation of moving picture and associated audio information on digital storage media. Ψ
MPEG standardization is best known for their video
compression, they also support high-quality audio compression. Ψ
There are currently Five MPEG Standards in various
stages of completion. Ψ
Each consists of numerous parts addressing aspects
of video Compression, storage, and delivery. MPEG-1: Ψ
ISO 11172, Coding of Moving Pictures and
Associated Audio for Digital Storage Media at up to about 1.5Mbits/s. (such
as CDROM) Ψ
A file contains a video, an audio stream, or a
system stream stream which interleaves some combination of audio and video
stream. Ψ
The MPEG-1 bit-stream syntax allows for picture
sizes of up to4095 x 4095 pixels. Many of the applications using
MPEG-1compressed video have been optimized the SIF (source intermediate
format) video format. Ψ
As in MPEG-1, input pictures are coded in the
YCbCr color space. This is referred to as the 4:2:0 sub sampling format. |
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|
S.NO |
RGPV QUESTIONS |
Year |
Marks |
|
Q.1 |
Define the following data and file format
standards: (i)TIFF (ii)DIB |
RGPV 2011 |
10 |
|
Q.2 |
Explain
briefly :-MPEG Standards |
RGPV 2014 |
7 |
|
Q.3 |
What are the steps involved in image preparation
used in JPEG image compression
.explain them with the help on diagram. |
RGPV 2012 |
7/10 |
|
UNIT
5 |
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|
Audio File
Format WAVE/ MIDI |
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Unit-05/Lecture-05 |
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File
Format Audio
( RGPV-2011,12,14)
WAVE
Native sound format by Microsoft Ψ
Based on
Interchange File Format (IFF) from Electronic Arts for Amiga Ψ
Basis of
Apples AIFF (Audio IFF) Ψ
One of the
RIFF file Ψ
The other
is AVI Ψ
File begins
with RIFF Ψ
But we can
use compression in WAVE files File
Format - Audio MIDI Musical
Instrument Digital Interface (MIDI) provides a relatively simple way for a
single keyboard to control a variety Of
instruments MIDI is a simple digital protocol and was rapidly incorporated
into computer music applications. The
MIDI is used as the foundation for Internet music playback and other new
kinds of music publishing. A
MIDI file is a sequence of chunks. These chunk have the same general format
as the chunks used by AIFF, IFF and WAVE;
each chunk has a 4-character type, a 4-byte length code (in MSB format), and
some data. Advantages Ψ
Store a
list of notes to be played is more compact than store the entire song Ψ
The music
can be modified conveniently. Ψ
Isolate a
particular instrument in a symphony Ψ
Great for
games as background music Ψ
Music can
be changed as the game progresses Ψ
General
MIDI specified 175 instruments Three
types of MIDI files: Type
zero files contain
only one track: There
are clearly the easiest to play, and preferred when you want to
make sure your MIDI files are easy for other people to play. Type
one files contain
multiple tracks that are played simultaneously: A program to play type one
files must somehow flatten the data into a single event stream before playing. Type
two file contain
multiple tracks but without assuming any timing relation among the tracks:
Type two files are
relatively uncommon. |
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|
S.NO |
RGPV QUESTIONS |
Year |
Marks |
|
Q.1 |
Explain channel reference and system message with reference to MIDI. |
RGPV 2012 |
10/7 |
|
Q.2 |
Discuss
briefly the various components of an audio system. |
RGPV
2014 |
7 |
|
UNIT
5 |
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|
Compression. |
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|
Unit-05/Lecture-06 |
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|
Multimedia Databases
(RGPV-2011,14) to
allow searching for pictures using characteristics such as color texture
shapes of objects to allow searching for audio (or say a song)characteristics
of personal features using certain specification of a program There
are many applications that include digital libraries (image catalog, musical
dictionary), multimedia directory services (yellow pages), broadcast media
selection (radio and TV channel) and multimedia edition (personalized
electronic news services). AVI
stands for Audio Video Interleave. It is a special case of the Resource
Interchange File Format (RIFF) which create by Microsoft for audio/video data
on PC and it becomes the de facto standard for uncompressed data. Other RIFF
file includes WAV for an audio andothers.AVI file contains the FOURCC (Four
Character Codes) codec ID for the video compressor in the video stream
header. http://www.jmcgwan.com/avi.html Compression Data- Ψ
Compression data is becoming an important subject
as increasingly digital information is required to be stored and transmitted. Ψ
Data Compression techniques exploit inherent
redundancy and irrelevancy by transforming a data file into a smaller file
from which the original image file can later be reconstructed,exactly or
approximately. Ψ
Some data compression algorithms can be classified
as being either lossless or lossy. Ψ
Video and sound images are normally compressed
with a lossy compression whereas computer-type data has a lossless
compression. Bandwidth
Requirement
E.g. bandwidth of a typical video file with 24bit true colour and a
resolution of 320 (H) x240 (V) pixels
Data per frame = 320 x 240 x 24 / 8 = 230kB
For desirable motion, we need 15frame per second.
Therefore uncompressed data per second= 230k x 15=3.45MB
If the video programme is 60 minutes in length, a
storage capacity for the video program me require
= 3.45M x 60 x 60 = 12.42GB
If we send it over the network, the bandwidth
requirement is = 3.45M x 8 = 27.6Mbps Lossless
Compression and Lossy Compression- There are two broad categories of data
compression: Lossless Compression: Such as
planar RGB, tiff and gzip Lossy Compression: Such as mp3, gif and jpeg Lossless
compression Where the information, once uncompressed,
will be identical to the original uncompressed data. This
will obviously be the case with computer-type data, such as data files,
computer programs. Any loss of data will cause the file to be corrupted. A lossless
compression algorithm the aim is to reduce the Amount
of source information to be transmitted. When the compressed information is
decompressed, there is no loss of information. Lossless compression is reversible.
An example application of lossless compression is for the transfer over a
network of a text file since, in such applications, it is normally
imperative that no part of the source information is lost during
either the compression or decompression operations. Lossless
compression consists of those techniques guaranteed to generate an
exact duplicate of the input data stream after a compress/expand cycle. The
most popular lossless coding techniques are Entropy, Huffman Coding
and Arithmetic Methods. Lossy
Compression
where the information, once uncompressed, cannot be fully recovered. Lossy
compression normally involves analyzing the data and determining which
information has little effect on the resulting compressed data. Compression
of an image might be used to reduce there solution of the image. Lossy compression
allows much lower data rates and file sizes than lossless compression, so lossy
codecs are commonly usedfor final production of video delivered using CD-ROM
or the Internet. |
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|
S.NO |
RGPV QUESTIONS |
Year |
Marks |
|
Q.1 |
Differentiate
between lossless and lossy compression techniques with the help of examples. |
RGPV2011,2014 |
10/7 |
|
Q.2 |
Explain
various multimedia Compression standards. |
RGPV2011 |
10/7 |
|
UNIT
5 |
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|
Multimedia Authoring |
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|
Unit-05/Lecture-07 |
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Multimedia Authoring- (RGPV-2011,12) An authoring system is a program which has pre-programmed elements for the development of interactive multimedia software titles. Authoring systems can be defined as software which allows its user to create multimedia applications for manipulating multimedia objects. In the development of educational software, an authoring System is a program that allows a non-programmer to easily create software with programming features. The programming features are built in but hidden behind buttons and other tools, so the author does not need to know how to program. Generally Authoring Systems provide lots of graphics, interaction, and other tools educational software needs. An authoring system usually includes an authoring language, a programming language built (or extended) with functionality for representing the tutoring system. The functionality offered by the authoring language may be programming functionality for use by programmers or domain representation functionality for use by subject experts. There is overlap between authoring languages with domain representation functionality and domain-specific languages. Authoring tool An
authoring tool is a software package which developers use to create and
package content deliverable to end users.Though authoring tools have a range
of uses, they are commonly used to create e-learning modules.
These modules are generally written to conform to some international
standard, such as SCORM (Shareable
Content Object Reference Model) or AICC (CBT) (Aviation
Industry CBT Committee). Distribution
of content created with authoring tools also varies. Distribution methods
include: web, kiosk, interactive CD-ROM, and executable file. Since
the term is somewhat general, many programs can be considered authoring
tools, including Flash, and PowerPoint. However,
only a small group of programs specifically include support for e-learning
content standards including Elicitus, Macromedia (Adobe) Authorware, Director, Lectora, and iSpring Suite. Authoring language. An
authoring language is a programming
language
used to create tutorials, computer-based training courseware, websites, CD-ROMs and other
interactive computer programs. Authoring
systems (packages) generally provide high-level visual tools that enable a complete
system to be designed without writing any programming code, although the
authoring language is there for more in-depth usage. Examples
of authoring languages-
PILOT
TUTOR Examples of web authoring languages
Bigwig
Multimedia Authoring System |
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|
S.NO |
RGPV QUESTIONS |
Year |
Marks |
|
Q.1 |
Explain multimedia authoring tools. |
RGPV-2011 |
7/10 |
|
Q.2 |
Describe
the characteristics of a multimedia database management system and its
objects when handling multimedia data. |
RGPV-2012 |
7 |
