Multimedia authoring and user interface
Multimedia
systems are different from other systems in two main respects the variety of
information objects used in application and the level of integration achieved
in using these objects in complex interconnected applications. In multimedia
applications, the user creates and controls the flow of data and determines the
expected rendering of it. For this reason, applications that allow users to
create multimedia objects and link or embed them in other compound objects such
as documents or database records are called authoring systems.
Multimedia authoring systems
Authoring
systems for multimedia applications are designed with the following two primary
target users in mind: professionals who prepare documents, audio or
soundtracks, and full motion video clips for wide distribution and average
business users preparing documents, audio recording, or full motion video clips
for stored messages or presentations.
Design issues of multimedia authoring
Display
resolution
Data
formats for captured data Compression algorithms Network interfaces
Storage
formats
A number
of design issues must be considered for handling different display outputs such
as Level of standardization on display resolutions
Display
protocol standardization Corporate norms for service degradations
Corporate
norms for network traffic degradations as they relate to resolutions issues.
File format and data compression issues
The
primary concern with very large objects is being able to locate them quickly
and being able to play them back efficiently. In almost all cases the objects
are compressed in some form. There is, however, another aspect of storage that
is equally important from a design perspective. It is useful to have some
information about the object itself available outside the object to allow a
user to decide if they need to access the object data.
1.compression
type
2.Estimated
time to decompress and display or play back the object [for audio and full
motion video]
3.Size of
the object [for images or if the user wants to download the object to a
notebook] 4.Object orientation [for images]
5.Annotation
markers and history[for images and sound or full motion video] 6.Index markers
[for sound full motion video]
7.Data
and time of creation 8.Source file
Design approaches to authoring
Designing
an authoring system spands a number of critical design issues,including The
following;
1.hypermedia
application design specifics 2.user interface aspects
3.embedding
/ linking streams of objects to a main document or presentation 4.storage of
and access to multimedia objects.
5.
Playing back combined streams in a synchronized manner.
Hypermedia
applications bring together a number of design issues not commonly encountered
in other types of applications. However as in any other application type, a
good user interface design is crucial to the success of a hypermedia
application. The user interface presents a window to the user for controlling
storage and retrieval , inserting objects in the document and specifying the
exact point of insertion, and defining index marks for combining different
multimedia streams and the rules for playing them back.
Types of multimedia authoring systems
Dedicated
authoring systems
Timeline-based
authoring
Structured
multimedia authoring
Programmable
authoring systems
Multisource
multi-user authoring system
Telephone
authoring systems
Hypermedia application design considerations
Multimedia
applications are based on a totally new metaphor that combines the television,
VCR and window-based application manager in one screen. The user interface must
be highly intuitive to allow the user to learn the tools quickly and be able to
use them effectively.
A good
designers needs to determine the strategic points during the execution of an
application
where
user feedback is essential or very useful. The following steps for good
hypermedia design
1. Determining
the type of hypermedia application
2. Structuring
the information
3. Determining
the navigation throughout the application
4. Methodologies
for accessing the information
5. Designing
the user interface
Integration of applications
Depending
on the job function of the knowledge worker, the computer may be called upon to
run a diverse set of applications, including some combination of the following.
Electronic mail
Word
processing
Graphics
and formal presentation preparation software
Spreadsheet
Access to
a relational
Customized
applications directly related to job function
Common UI and application integration
The
Microsoft has different user interface for a large number of applications by
providing standardization at the following levels.
Overall
visual look and feel of the application windows Menus
Dialog
boxes Buttons Help feature Scroll bars Tool bars
File open
and save
Data Exchange
The MS
clipboard allows exchanging data in any format. The clipboard can be used to
exchange multimedia objects as well, including cutting or copying a multimedia
object in one document and pasting it
in
another.
Distributed data access
Application
integration succeeds only if all applications required for a compound object
can access
the sub
objects that they manipulate. Fully distributed data access implies that any
application at any client
workstation
in the enterprise-wide WAN must be able to access any data object s if it were
local.
User interface design
User
interface design for multimedia applications is more involved than for other
applications due to the number of types of interactions with the user.
Four
kinds of user interface design is available such as Media editors
An
authoring application Hypermedia object creation Multimedia object locator and
browser
A media
editor is an application responsible for the creation and editing of a specific
multimedia object such as an image, voice or video object.
Designing user interface
The
correctness of a user interface is a perception of a user.
Guidelines
Planning
the overall structure of the application
Planning
the content of the application
Planning
the interactive behavior
Planning
the look and feel of the application
Special metaphors for multimedia applications
Multimedia
applications bring together two key technologies; entertainment and business
computing.
The
organizer metaphor
The
multimedia aspects of the organizer are not very obvious until one begins to
associate the concept of embedding multimedia objects in the appointment diary
or notepad for future filling. The telephone metaphor
The
telephone, until very recently, was considered an independent office appliance.
The advent of voice mail systems was the first step in changing the role of the
telephone.
Aural
user interface
The
common approach for speech-recognition based user interfaces has been to graft
the speech recognition interface into existing graphical user interfaces. This
is a mix of conceptually mismatched media that makes the interface cumbersome
and not very efficient.
The real
challenge in designing AUI systems is to create an aural desktop that
substitutes voice and ear for the keyboard and display, and be able to mix and
match them.
The VCR
metaphor
The
easiest user interface for functions such as video capture, channel play and
stored video playback is to emulate the camera, television, and VCR on screen.
Audio and
video indexing functions
Audio
tape indexing has been used by a large number of tape recorders since the early
1950s. Index marking on tape is a function that has been available in many
commercial VCRs. Index marking on
tape left
a physical index mark on the tape. These index marks could be used in fast
forwarded and rewind
searches.
Hypermedia messaging
E-mail based document interchange, generally known as messaging services. Messaging is one of the major multimedia applications. Mobile messaging represents a major new dimension in the user’s interaction with the messaging system. Handheld and desktop devices, an important growth area for messaging, require complementary back-end services to effectively manage communications for a large organization. An answering service can take multiple messages simultaneously irrespective of line usage. The roles of telephone carries and local cable companies are starting to blur.
Hypermedia message components:
A
hypermedia message may be a simple message in the form of text with an embedded
graphics, soundtrack, or video clip. The components of hypermedia messages are
handled through the following
three
steps.
The user
may have watched some video presentation on the material and may want to attach
a part of that clip in the message.
Some
pages of the book are scanned as images. The images provide an illustration or
a clearer analysis of the topic.
The user
writes the text of the message using a word processor.
When the
message is fully composed, the user signs it and mails the message to the
addressee. The messaging system must ensure that the images and video clips referenced
in the message are also transferred to a server local to recipient.
Message
types Text messages Rich-text messages Voice messages
Full-motion
video management
Hypermedia
linking and embedding
Linking
and embedding are two methods for associating multimedia objects with
documents. Linking as in hypermedia applications. Hypertext systems associate
keywords in a document with other documents.
Linking
multimedia objects stored separately from the document and the link provides a
pointer
to its
storage. An embedded object is a part of the document and is retrieved when the
document is retrieved.
Linking
and embedding in a context specific to Microsoft object linking and embedding.
When a multimedia object is incorporated in a document, its behavior depends on
whether it is linked or embedded. The difference between linking and embedding
stems from how and where the actual source data that comprises the multimedia
object resides.
Linking
objects:
When an
object is linked, the source data object, called the link source, continues to
reside wherever it was as the time the link was created. This may be at the
object server where it was created, or where it may have been copied in a
subsequent replication.
Embedding
objects:
When the multimedia
object is embedded, a copy of the object is physically stored in the hypermedia
document. Graphics and images can be inserted in a rich-text document or
embedded using such techniques as OLE.
Design
issues:
For users
who have a requirement for component documents, OLE represents an important
advancement in systems and application software on distributed platforms. OLE
will create significant support headaches for users if there is incomplete link
tracking between documents that have been mailed between PCs and the
application which created those objects.
Creating
hypermedia messages:
A
hypermedia message can be a complex collection of a variety of objects. It is
an integrated message consisting of text, binary files, images, bitmaps, voice
and sound.
Procedure:
Planning
Creating
each component Integrating components
Integrated
multimedia message standards:
As
text-based technologies have progressed and have become increasingly integrated
with messaging systems, new standards are being developed to address
interoperability of application from different software vendors.
Vendor-independent
messaging
Vendor
independent messaging interface is designed to facilitate messaging between
VIM-enabled electronic mail systems as well as other applications. A VIM
interface makes mail and messaging services available through a well-defined
interface. A messaging service enables its clients to communicate with each
other in a store-and –forward manner. VIM defines messaging as the data
exchange mechanism between VIM aware applications.
VIM mail
message is a message of a well defined type that must include a message header
and may include note parts, attachments, and other application-defined
components.
VIM
services
The VIM
interface provides a number of services for creating and mailing a message such
as, Electronic message composition and submission
Electronic
message sending and receiving Message extraction from mail system Address book
services
The
developers of VIM targeted four areas in which VIM could fit into the business
process: mail
enabling
existing applications, creating alert utilities, creating scheduling
applications, and helping workflow
applications.
The benefits of implementing applications in each of these four areas vary significantly.
MAPI
MAPI is
to provide a messaging architecture rather than just providing a messaging API
in windows. MAPI provides a layer of functionality between applications and
underlying messaging systems.
Goals
Separate
client applications from the underlying messaging services
Make
basic mail-enabling a standard feature for all applications
Support
messaging- reliant workgroup applications
Telephony API
The TAPI
standard has been defined by Microsoft and Intel, and has been upgraded through
successive release to stay abreast of on going technology changes.
X 400 Message handling service
The MHS
describe a functional model that provides end users the ability to send and
receive electronic messages. A user agent is an entity that provides the end
user function for composing and sending messages as well as for delivering
messages. Most user agent implementations also provide local mail management
functions such as storage of mail, sorting mail in folders, purging and
forwarding. When a user composes a message and sends it the UA communicates the
message to and MTA. If there is no local MTA, the message is forwarded to the
MTA in a submission envelope based on one of a set of message protocol data
units(MPDU) defined in the submission and delivery protocol. The delivery
protocol is designed to use a remote operations service and optionally, a reliable
transfer service to submit message to the MTA.
A
collection of MTAs and UAs constitutes a management domain. Administrative
management domains are public services such as AT&T, Sprint and so on.
Distributed
multimedia systems:
A
multimedia system consists of a number of components , which are distributed
and dedicated function with different locations.
Components:
Application software Container object store Image and still video store
Audio and
video component store Object directory service agent Component service agent
User
interface service agent Networks
The
application software is the multimedia application that creates, edits or
renders multimedia objects.
The
container object store is used to store container objects in a network object
server. A image or still video store is a mass storage component for images and
still video.
An
audio/video component store is the storage resource used for storing audio and
video objects. An object directory service agent is responsible for assigning
identification for all multimedia object types managed by that agent.
A
component service agent is responsible for locating each embedded or linked
component object of a multimedia container, and managing proper sequencing for
rendering of the multimedia objects.
A user
interface service agent is responsible for managing the display windows on a
user workstation, interacting with the user, sizing the display windows, and
scaling the decompressed object to the selected window size.
The
network as used in this context refers to the corporate wide network consisting
of all LAN and WAN interfaces required for supporting a particular application
for a specific group of users. Distributed client-server operation:
While the
client server architecture has been used for some time for relational databases
such as Sybase and Oracle. Most client-server systems were designed to connect
a client across a network to a server that provided database functions. The
clients in this case were custom-designed for the server.
Client in
distributed workgroup computing
The
client systems interact with the data servers in any of the following ways:
1. Request
specific textual data
2. Request specific
multimedia objects embedded
3. Require
activation of rendering server application to display
4. Create
and store multimedia objects on servers
5. Request
directory information on locations of objects on servers. Servers in
distributed workgroup computing
1. Provide
storage for a variety of object classes
2. Transfer
objects on demand to clients
3. Provide
hierarchical storage for moving unused objects to near-line media
4. System
administration functions for backing up stored data
5. Direct
high-speed LAN and WAN server-to-server transport for copying multimedia
objects. Database operations
Search
Browse Retrieve
Create
and store Update
Middleware
in distributed workgroup computing
1. Provide
the user with a local index, an object directory, for objects with which a
client is concerned
2. Provide
automatic object directory services for locating available copies of objects
3. Provide
protocol and data format conversations between the client requests and the
stored formats in the server
4. Provide
unique identification throughout the enterprise wide network for every object
through time.
Multimedia
object servers:
The
resources where information objects are stored so that they remain sharable
across the network are called servers.
Types of
multimedia servers Data processing servers Document database servers
Document
imaging and still video servers Audio and voice mail servers Full-motion video
servers.
Network
topologies for multimedia object servers Centralized multimedia server
Dedicated
multimedia servers Distributed multimedia servers Multimedia network topologies
Traditional LAN
Extended
LANs High-speed LANs WANs
Distributed
multimedia database
A
multimedia database consists of a number of different types of multimedia
objects. Database organization for multimedia applications
Data
independence
Common
distributed database architecture Multiple data servers
Transaction
management for multimedia systems Managing hypermedia records as objects
Multimedia
objects need not always be embedded in the database record or a hypermedia
document; instead, a reference can be embedded, and the multimedia object can
reside separately in its own database, potentially optimized for that type of
multimedia object.
Managing
distributed objects The issues are
How
objects are located, and once located , how retrieval is managed in a
multi-user environment, replication, archival, load balancing and purging.
The above
issues are addressed with the following concepts Interserver communications
Object
server architecture Object identification
Object
revision management Optimizing network location of objects Object directory
services
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