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ADAPTATION OF APPLETS AND LIVE VIDEOS TO MOBILE DEVICES

ADAPTATION OF APPLETS AND LIVE VIDEOS TO MOBILE DEVICES. J Manoj Kumar (M.Tech IIT Bombay) Guided by: Prof. Sridhar Iyer. Problem Definition. Adapt CDEEP Live Videos to Mobile Devices. Adapt to low bandwidth networks. Problems in video streaming to mobile devices

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ADAPTATION OF APPLETS AND LIVE VIDEOS TO MOBILE DEVICES

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  1. ADAPTATION OF APPLETS AND LIVE VIDEOS TO MOBILE DEVICES J Manoj Kumar (M.Tech IIT Bombay) Guided by: Prof. Sridhar Iyer

  2. Problem Definition • Adapt CDEEP Live Videos to Mobile Devices. • Adapt to low bandwidth networks. • Problems in video streaming to mobile devices • Limited Memory in Mobile devices. • Low Bandwidth of Mobile Network like GPRS. • Adapt Java Applets to Mobile Devices • Java Applets are built with J2SE technology that do not work on mobile devices. • Limited Memory in Mobile devices. • Mobile devices work on J2ME technology.

  3. Adaptation Of CDEEP Live videos to Mobile Devices

  4. Existing System - Study Element Based System • Works only for “stored CDEEP videos”

  5. Study Element Based System • Three types of Study Elements are categorized • Presentation Element -- portion of video that shows one slide of presentation. • White paper Element – portion of video that shows white paper. • Instructor Element – portion of video that shows instructor.

  6. Classifying Images • Classification -- Feature based Tagging • Feature -- a unique property

  7. Proposed System

  8. Live Video Adaptation Module • Capture sets of 300 images from Live stream. • Classify each set of images study elements. • Copy images and audio to server.

  9. Image Extraction Methodology • Approach 1: • Using Video LAN(VLC) • Save or Record for five minutes. • Extract Images from saved video. • Disadvantages • High CPU utilization because of Video transcoding. • Delay between actual video and seeing video increases for each iteration.

  10. Convert to MJPEG Stream • MJPEG - Motion JPEG ( Images are shown one after the other). Ex: surveillance camera. • Images are separated by delimiter. • Disadvantages • High CPU Utilization because of Video Transcoding. • Unable to display images.

  11. Approach 2: • Using FFmpeg • Images extracted directly from live stream. • ffmpeg -i url -an -r 1 -f image -s 320x240 video%d.jpg • Group images to sets of 300. • Using Mplayer: • Images extracted and grouped directly from live stream. mplayer -nosound -vf framestep=25 -vo jpeg:subdirs=img:maxfiles=300 url

  12. Audio Extraction • Using FFmpeg • Audio is saved in the form of mp3 chunks. • ffmpeg -i url -t 00:00:20 -acodec libmp3lame -ab 24 -ar 8000 audio.mp3 • Generate XML

  13. System Implementation

  14. Sequence Diagram

  15. Design Considerations • Port blocking in GSM networks • Direct TCP connections not possible due to port blocking. • Allows only HTTP connection to ports 80 and 8080. • Audio Streaming • Audio streaming to mobile device is not supported. • Hence, need to do progressive download.

  16. Usage • Enter URL 2. select video 3. slide show

  17. Comparison to Existing System • Supports automatic creation of offline copy of video. • Live video can be viewed as soon as it starts. • Misclassifications of images cannot be corrected.

  18. Adaptation of Applets to Mobile Devices

  19. Project OSCAR • Project OSCAR – Open Source Courseware Animations Repository. • Repository for web-based, interactive animations for various teaching concepts. • Animation is typically an Java Applet with brief description of concept.

  20. Overview of J2ME • Java Micro Edition J2ME – small devices like mobiles, PDA’s with low RAM and speed. • J2ME has 3 principles • Configuration – JVM + set of API’s • Profile – set of API’s designed for specific configuration • Optional package –technology specific API’s to extend the capabilities of JVM

  21. Architecture of J2ME

  22. J2ME • Configuration: specifies JVM and core set of API’s for a specific family of devices. • Two types of configuration • Connected Device Configuration CDC – minimum of 512KB ROM, 256KB of RAM, full JVM must be supported. • High end PDA’s, TV setup boxes, car navigation systems. • Connected Limited Device Configuration CLDC – minimum of 160KB of ROM, 32KB RAM, KVM • Mobiles, pagers, PDA’s. • Cannot add native methods.

  23. J2SE Applets to J2ME Conversion Difficulties • Incompatibility of Architectures of J2SE and J2ME MIDlet architecture Applet Architecture • Only one form per screen in MIDlet, Multiple panels in applet. • Difficult to convert from J2ME architecture to J2SE architecture.

  24. . • Canvas size and Co-ordinates of Image Object • Designed for Desktop systems • Co-ordinates have to be set manually – cannot be automated Sample OSCAR paint code public void paint(Graphics G){ g.drawImage(Image img1, 480, 600,this); g.drawImage(Image img2, 530, 400,this); g,drawImage(Image img3, 60, 370, this); }

  25. Amount of Text on Screen • Designed for Desktop Resolutions – cannot be fit mobile screen, preplanning cannot be automated. Sample OSCAR animation with text field. public void init(){ ta = new TextArea("", 31, 47); ta.setText("\n\t Energy Transaction in Biological Systems\n"+ "\n In this animation you will learn the concepts of ATP Metabolism………. ……………… 10 lines };

  26. Other General Differences • No floating point support in J2ME. • No Java Native Interface (JNI) in J2ME. • No finalize method in J2ME. • No Thread Groups.

  27. J2SE to J2ME – Conversion Possibilities • Copy of Paint Method J2ME uses J2SE’s Graphics class with minor changes -- enables copy paint method as it is during conversion Sample applet with paint method public void paint( Graphics g){ g.drawString("Sending",150,75); g.drawRect("40,50,10,20); g.drawImg(Image img,20,30,center); g.drawArc(30,40,10,30,60,120);} g.drawString, g.drawRect, g.drawImg, g.drawArc are common in both j2se and j2me

  28. Buttons to Key mapping • J2ME doesn’t display buttons, it uses mobile device keys take input • OSCAR animations -- buttons like start, stop. • Buttons to key mapping is possible. • LWUIT • Light Weight User Interface Toolkit is a UI library developed by Sun. • Offers advanced UI capabilities and API inspired by Swing. • LWUIT allows multiple panels on screen.

  29. Overview of Flash and Action Script • Flash – multimedia platform language for creating animations • Action Script can be embedded. – ECMA script. • AS is Object Oriented similar to Java Script. • AS + Flash – more interactive animations. • Used to build Rich Internet Applications. • Flash Lite – highly optimized flash runtime for mobiles. • Provides same functionality similar to desktop.

  30. Applet to Flash – Conversion Difficulties • No Multi-Threading in Flash • Multi-Threading – two or more parts in a program to run concurrently ( Multitasking ). • Essential ability to have code do something while UI is doing something else. • Single Thread – Having heavy computation, cannot update UI. • Program becomes un-responsive and crashes after 60 seconds. Sample OSCAR program with thread class Timer extends Thread { //code// void Settime(); void sleep(); }

  31. Conversion difficulties • No method(function) overloading • Difficult for multiple methods – if constructor overloading • Sample java program public void defaultSetter(int iValue) { setter(iValue, false); } public void setter(int iValue, boolean bForce) { // whatever } In action script public function setter(iValue:int, bForce:Boolean = false):void { // whatever }

  32. Other General Difficulties and Possibilities • Limited Data Structures • Action script supports only Arrays and Dictionary. • No queues, no linked List, no stack compared to Java. • Need to re-implement data structures which are wrapped. • No Blocking • Next code of line is supposed to run, user cannot prevent it from run – Alert.show(); does not stop exexctuing next line. • Possibilities • Java and Action Script have same syntax with a little change. • Syntax change automated by Java to Action script converter (J2AS3)

  33. Conclusion • Successfully integrated to existing Study element based adaptation. • Live video transmission of CDEEP videos can be adapted to networks with low bandwidth. • Automated porting Java applets to mobile devices as J2ME MIDlets and flash files is difficult and infeasible.

  34. Future Work • Decrease Misclassifications of images • Study element based system is prone to errors. • Better feature based classification. • Synchronization between audio and images • Synchronizing audio with the image slideshow. • Text Improvement • Identify text in study elements and improve text quality.

  35. References • Fabrice Bellard. Ffmpeg codec manual. http://www.ffmpeg.org/ffmpeg-doc.html . • Free Software Foundation. Mplayer manual. http://www.mplayerhq.hu/DOCS/HTML/en/index.html. • G.N. Murthy and S. Iyer. Study element based adaptation of lecture videos to mobile devices. In Communications (NCC), 2010 National Conférence on, pages 1 - 5, 29-31 2010. • Herbert Schildt . Java 2ME the complete reference. Osborne/McGraw-Hill, fourth edition, 2001.

  36. Questions?

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