Computer Network Project Computer Network Project Efficient handling of messages with multimedia attachments

The Problem In order to guaranty efficient handling of messages with multimedia attachments, we must insure the following: End users capability to open the file attached. End users capability to open the file attached. Minimal network cost. Minimal network cost. Avoid wasting the networks resources, by sending files that later can not be used. Avoid wasting the networks resources, by sending files that later can not be used.

The Projects Goal Investigate the different formats supported by the multimedia standard. Define an algorithm, which will decide the format in which the Multimedia file will be send in and later stored in, by taking the following aspects under consideration. The conversions abilities available. The conversions abilities available. The conversions costs. The conversions costs. The conversion capabilities of the mail server and end user. The conversion capabilities of the mail server and end user. Conversion times (between the different standards). Conversion times (between the different standards). The network efficiency. The network efficiency.

Standard multimedia formats The AVI Format. The MPEG2 Format. The MPEG4 Format.

Profiles and Levels The MPEG 2 & 4 formats are divided into many profiles and levels. The common profiles and levels used today: MPEG-2 Main profile in Main level. Main profile in Main level. SNR profile in Main level. SNR profile in Main level.MPEG-4 Simple profile in L0 level. Simple profile in L0 level. Simple profile in L1 level. Simple profile in L1 level. Simple profile in L2 level. Simple profile in L2 level. AVI format

Solution description Given a source format, a list of destination formats and the converting abilities of the source and destination server find the most suitable conversions tree under the following restrictions: The tree should be the lightest tree that we can get in a manner of conversion and transmission costs. There will be a limit on the number of file formats that could be transferred over the network.

Solution description cont. Inputs Source file’s format. End-user’s encoding capabilities (destination formats). Mail server’s conversions abilities and costs. Network costs for sending a specific file format. Number of times we can transmit through the network. All these inputs will be used to create an initial graph which it itself will be the algorithms input. Outputs Conversion-tree: after the algorithm is executed we will receive a minimal weighted path tree which represents the conversions should be made in order to deliver the multimedia file to the end-users in the format they can encode. The tree will state where the conversions should be made and which file formats should be sent through the network.

Creating the initial graph Graph vertex: Different file formats. Graph edges: Possible conversions between file formats or transmission of file format through the network. Weights: Conversions time on the different servers. Transmission costs through the network The initial graph has two layers. The upper layer represents the conversion abilities of the source mailing server and the bottom layer represents the conversion abilities of the destination mailing server. Connecting these layers are the edges representing the networks transfer abilities. Note that over the network the file must stay in the format in which it is sent. This initial graph will represent the algorithms input and we will receive as output the minimal weighted path tree (the conversion tree).

The algorithm Our algorithm is based on the ASTAR algorithm, which uses heuristic function in order to create a “minimal weighted path tree”. After building the initial graph and defining the source format (In the initial graph upper level) as the “head” and the vertexes that represent the formats we want the end users to receive (in the initial graph bottom level) as “target vertexes”, it starts the calculation. The algorithm builds the conversions-tree in the following method: It runs the ASTAR algorithm. Each step the minimal tree created until that point is taken out of the open list and all its successors are calculated and placed in the open list at their proper place. Again the minimal tree is chosen and so forth. The heuristic function is based on the number of “target vertexes” in the “minimal weighted paths tree”. The algorithm stops when the tree which was built contains all the “target vertexes” and it is the lightest tree it can get.

Example The initial tree Source format : Mpeg2 Destination Formats : Mpeg4, AVI Network crosses allowed: 1 Mpeg2 AVI Mpeg4 AVI

Step One The open list: Mpeg2 Open = } {

Step Two The open list: Open = { Mpeg2 AVI 0.9 } Mpeg2 2 Current minimal tree

Step Three The open list: Open = { } Mpeg2 2 Current minimal tree Mpeg2 AVI 0.9 8

Step Four The open list: Open = { } Current minimal tree Mpeg2 AVI Mpeg2 Mpeg4 2 2

Step Five The open list: All the destination formats reached Open = { } Current minimal tree Mpeg2 AVI Mpeg2 AVI Mpeg

The Conversion tree The output of the algorithm Cost: 5 Mpeg2 AVI Mpeg

Using the Program

Load from XML Press Form XML tab

Load from XML Open XML file 1.Pressing Browser button 2.choosing the Path from Dialog box 3.Pressing Load Data From XML button

Load from XML Initial Data and start calculation 1.Choose Source & Destination Formats 2.Choose The number of times we can send data over the net 3.Choose Network transfer weight 4.Press Start Calculation button to start the algorithm

Load from Excel Press Form Excel tab

Load from Excel Open XML file 1.Pressing Brower button 2.choosing the Path from Dialog box 3.Pressing Load Data From Excel button

Load from Excel Initial Data and start calculation 1.Choose Source & Destination Formats 2.Choose The number of times we can send data over the net 3.Chooser Network transfer weight 4.Press Start Calculation button to start the algorithm

Create Excel file Press Create Excel File tab

Create Excel file Retrieve Formats from text file 1.Pressing Brower button 2.choosing the Path from Dialog box 3.Pressing Load Formats from Text file

Create Excel file 1.Choose Formats 2.Press Create Excel File button

Create Excel file Fill the data in the new generated Excel File 1.Source Weights 2.Destination Weights 3.Network Weights

Calculation Result Press Result tab

Calculation Result The result tree is printed as arcs holding the following data 1.Source node (Format) 2.Destination node (Format) 3.Platform (The type of arc  Source / Destinaion / Network) 4.Weight

Calculation Result Create XML file from the result 1.Press Browser button to choose path 2.choose path 3.Press Created XML Solution to create XML file