designing applications with multimedia capabilities

Designing applications with multimedia capabilitiesMr.K.Senthil Kumar,Assistant Professor,Sri Eshwar College of Engineering, Coimbatore 641 202

Design steps for any MM application

1. Specify the business modelThis includes the business requirement that the MM software system should satisfy.

Design steps for any MM application / case study ……. Contd…..

2. Specify the business information modelThis includes the following :

Types of users Operation performed by each type of user Performance requirement ( most important )

Performance requirement calculates the required download bandwidth for each component – A,V,I and text and storage space required for storing each one.Here state availability requirement if the application should be 24 * 7 .

Design steps for any MM application Contd…..

3. Architectural recommendation and technology feasibility report

To achieve performance requirement calculated in above step Architectural recommendation indicate the following aspects of the step :

Topology of the network Types of servers Location of database servers Communication and networking protocols. Security considerations ( only if specifically asked ) Database integrity considerations. ( only if specifically

asked )


4.Object architecture This is important when we design a

distributed MM system.This diagram indicates different components

required in a distributed system like Object request brokerObject name serverA,V,I – show each MM component server

separately. Object directory manager


5. Workflow Workflow is a set of steps which govern the flow of data and or information to produce a tangible output.

Please remember as regards MM there are only 4 types :

1. Training manuals and online help2. Information databases 3. Messaging systems4. Business processes

About Workflow…. Any workflow has simple three stages Capture stage: This includes

capturing of image through digital camera or scanner checking its quality. Indexing i.e. finding unique information and storing it

separately in index tables.

About Workflow….

User access stage This is always mentioned relatively as it is very specific to the application to be implemented. For eg : OLE, possible output modes.

Archiving and purging stage : Archiving means taking periodic backup for immediate future use. Backup means saving data on offline storage for future reference if any. Purging means removing data / information no longer needed


6. Object design ( also called MM authoring)

This includes the following : 1. Database schema design 2. Categorizing different components into

audio, video, image and text. Please note for this u have to read the case study thoroughly.

3. Making MM user interfaces.

Case study exampleContinuous education program : One of the most important application using both technologies, networks and multimedia, is distance learning. Computers offer the chance for new educational procedures, which in combination to networks reach levels beyond imagination. Anyone could be educated by the greatest teachers of the world. Computers cannot replace the teacher, but they can bring him closer to the student.

Assume required data if any and specify clearly. You are appointed as a consultant to implement this application.

Case study example1. Design the performance requirements if

this application is to be used in distributed environment

2. Give the workflow design.

3. Model the various objects and design special multimedia user interface.

Step 1 : Specify the business model

1) Spread the domain of education.2) Facilitate the virtual learning of

students from best teachers without bothering of physical boundaries.

3) Resolve space & time problem of student and teacher alike.

Step 2: Specify the business information model

1) Types of Users : There are broadly two types of users :a) Students b) Teachers

2)Operation Performed by Users :a) Role of Student : 1) Browsing 2) Register

3 ) Fetch Information 4) Download White papers 5) Choose Course & specialization subjects 6) Pay online 7) Enroll for multiple courses.

Step 2: Specify the business information model Contd….

b) Role of teacher :a) registerb) upload informationc) open forumsd) resolve queries

Step 3) Performance Requirements To find Bandwidth, and storage Requirements;

following assumptions are made : 1) Online University offers 40 courses / subjects / technical / literature based enrollments.2) There are 1000 Hits on the web site.3) About 400 students take there tutorials daily.4) Every tutorial has a Interactive class room session, Object based test papers, containing video clips, Audio to support the lecture, text to support literature about current topic.5) There are at most 5 active users downloading content at any point of time.

Performance requirement calculation:

1) Video content in Tutorials :Frames = 320 x 200 @ 30 frames / sec and 8 bit colour = 1.92 MB / sec

For 30 minutes of lecture (in video) space required = 1.92 x 30 x 60 = 3.456 GB If compressed with compression Ration = 30:1Then space required / per lecture = 3.456 GB / 30

= 115.2 MB

For 5 users total Required Space = 115.2 MB x 5 = 576 MBAnd download BW required is very high therefore choose leased line T1 connection ( not shared )= 1.544 Mbps


2 ) Audio (speech) content in Virtual Close Room LectureFor 30 minutes lecture, 8 KHz / sample, 8 bits / sample

= 8 KB / sec x 30 x60 = 14.4 MBSpace required for 1 session = 14.4 MBSpace required for 5 Active Users = 14.4 x 5 = 72 MBIf compressed with 30:1 Ratio = 72 MB = 2.4 MB

30Network Bandwidth (Download B.W.) Required :2.4 MBps, but this kind of high B.W is practically and financially not feasible. Therefore previously chosen T1 line is acceptable.


3) Images : - Average compressed image = 30 KBAssuming 20 Images per session download = 30 x 20 = 0.6 MBCompressed (20:1) = 0.6 MB = 0.03 Mb = 30 KB

20For 5 Active users total space required = 30 KB x 5 =

150 KBNetwork Bandwidth = 150 KB / sec (Download B.W)

T1 line is sufficient for above BW requirement.


Therefore, Total space required at content server end =~

576 MB + 72 MB + 0.15 MB = 649 MB

Therefore 1 GB buffer (Working memory) space at server end sufficient enough to cater 6 ( 5 + 10 % tolerance )users taking virtual classroom coaching.

Step 3) Architectural Recommendation to support above performance requirements

Topology of the network Types of severs Location of database servers Communication and networking

protocols

High SpeedFiber Optic

(FDDI II) Link

Object Server

ATMSwitch

Client

Client

Client

ATM Hub

Object Server

ObjectRetriever

ObjectManager

Client Client

Object Server

Client

Object Server

ATMSwitch

Client

Internet

Step 4 Object architecture

Object Server

Object ManagerReplicationMigrationArchival

Class-SpecificFunctionsPurging

Object Server

Multimedia Application

Common Object Management API

Object NameserverObject Directory Service

Object Request BrokerObject Recompilation, Playback Control, Format Conversions

Object Server

Object ManagerReplicationMigrationArchival

Class-SpecificFunctionsPurging

Object RetrieverRetrieve Full Object

Playback on DemandODMS

Object RetrieverRetrieve Full Object

Playback on Demand

Performance Attributes Achieved :from architectural layout

a) Good Response timeb) Quick & efficient search due to object indexingc) Good availability and failsafe operation as object server replication done.d) User friendliness.

Step 5 : Workflow DesignIV) : Capture Stage : The video conversation or a

stored video mail message are recorded as a part of document or a database record. A video camera and appropriate sound and video hardware are required for this. The captured information is recorded directly on an object server for multimedia objects.

User Access Stage : The workflow is designed to allow the user to retrieve the container document via a database. The container document has the embedded objects for the video message or video conversation and other embedded or linked objects or shared workspace.

Archiving and Purging : Allow the user to perform the archiving and purging; no automatic facilities are provided. Only if he purchases a case paper i.e. transaction takes place.

Step 5 : Workflow Design … contd… Above workflow for virtual university, supports

following features : a) They are primarily playback-only systems. End

users do not add information components to these systems.

b) The input and output components of the workflow are completely independent of each other and may or may not reside on the same network.

c)Size of the database is large and the need for indexing every component in an information repository is a must. In addition, these systems also require the ability to adjust the display quality and window size on the basis of the workstation hardware and user preferences.

Step 6 : MM object design The various objects which will be used for

distance learning will be :Text : Lecture notes, tutorials, textbooks,

references, technical papers, journals, manuals.Images : Book cover (Covering name & author),

lecturer image, flash image at the start and end of the lecture, images of various icons, image of student – lecturer interaction, various images related to the lecture subject like diagrams, drawings, maps etc.

Audio: The lecturer’s talking, students question, sound of flash image indicating start and end of the lecture.

Video : Video conferencing overall, display of some classroom virtual tour.

designing applications with multimedia capabilities

Education