AN EXTENSIBLE TRANSCODER FOR HTML TO VOICEXML CONVERSION APPROVED BY SUPERVISORY COMMITTEE: Supervisor: AN EXTENSIBLE TRANSCODER FOR HTML TO VOICEXML CONVERSION by Narayanan Annamalai, B.E. in CSE THESIS Presented to the Faculty of The University of Texas at Dallas in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE IN COMPUTER SCIENCE THE UNIVERSITY OF TEXAS AT DALLAS May 2002 Copyright c 2002 Narayanan Annamalai All Rights Reserved Dedicated to my Parents ACKNOWLEDGEMENTS My sincere gratitude goes to my advisors Dr. Gopal Gupta and Dr. B Prabhakaran for being instrumental in shaping my ideas and helping me achieve my ambitions. But for their guidance, it would not have been possible for me to complete my thesis. I would also like to thank Dr. Latifur Khan for serving in my thesis committee. I would like to extend my sincere gratitude to all my family, friends who have been sup- portive and encouraging all through my career. Finally, I would like to thank my fellow graduate students Srikanth Kuppa and Vinod Vokkarane for reading my thesis draft and providing me valuable suggestions and helping me with the format of the draft. v AN EXTENSIBLE TRANSCODER FOR HTML TO VOICEXML CONVERSION Publication No. Narayanan Annamalai, M.S The University of Texas at Dallas, 2002 Supervising Professors: Dr. Gopal Gupta and Dr. B Prabhakaran ‘Anytime anywhere Internet access’ has become the goal for current technology vendors. Sudden increase in the number of mobile users has necessitated the need for ‘Internet access through mobile phones’. The existing web infrastructure was designed for traditional desktop browsers and not for hand-held devices. The data in the web is stored in HTML (Hyper Text Markup Language) format which cannot be delivered to mobile devices. The only acceptable way to present data to devices like cellular phones, is audio. Certain voice browsers are capable enough to process VoiceXML content and produce the output in the form of audio. Thus it is imperative that a transcoder which converts HTML data to VoiceXML data is developed. In this thesis, we propose and implement a system which converts HTML (4.0 or lower version) file to corresponding VoiceXML file. The transcoder is divided into two phases: The parsing phase where the input HTML file is converted to HTML node tree, and the translating phase where each node in the HTML tree is mapped to its equivalent VoiceXML node. Our transcoder is extensible in the sense it can be upgraded easily by users to accommodate new HTML tags in the future. vi TABLE OF CONTENTS Acknowledgements v Abstract vi List of Figures ix List of Tables x Chapter 1. INTRODUCTION 1 1.1 Voice Enabled Applications . 1 1.2 Related Work . 2 1.3 The Thesis. 4 1.4 Research Objectives. 4 1.5 Contributions . 5 Chapter 2. INTRODUCTION TO VOICEXML 6 2.1 What is VoiceXML? . 6 2.2 VoiceXML Features . 6 2.3 Architecture . 7 2.4 Framework . 7 2.4.1 Dialogs . 8 2.5 Grammar . 8 2.5.1 Scope of Grammars . 9 2.6 Elements of VXML files . 9 2.6.1 Event Handling . 11 2.6.2 Links . 12 2.6.3 Forms . 12 2.6.4 Field Items . 12 2.6.5 Control Items . 13 2.6.6 Form Interpretation.. 13 2.6.7 Menus . 13 2.6.8 Prompts . 14 2.7 HTML 4.0 . 14 2.7.1 Table . 14 2.7.2 Forms . 15 2.8 Comparison of HTML versus VoiceXML . 15 vii Chapter 3. SYSTEM MODEL AND ASSUMPTIONS 17 3.1 Architecture . 17 3.2 Assumptions. 19 Chapter 4. TRANSCODER LOGIC 21 4.1 Parsing Phase . 21 4.2 Translation Phase . 23 4.3 Structure . 24 4.4 Framework of the Overall Process . 25 4.5 Translation Issues . 25 4.6 Translator Logic . 28 4.6.1 Form Tags . 28 4.6.2 Link Tags . 32 4.6.3 Image Tags . 32 4.6.4 List Tags. 33 4.6.5 Frame Tags . 34 4.6.6 Spacing/Layout Tags . 35 4.6.7 Rule Tags . 35 4.6.8 Tables . 35 4.6.9 Text Tags . 37 4.7 Pseudo-code of the Algorithm . 37 4.8 Implementation Details. 38 Chapter 5. CONCLUSION AND FUTURE WORK 40 5.1 Applications . 41 5.2 Future Work . 41 Bibliography 44 Vita 47 viii LIST OF FIGURES 2.1 System Architecture . 7 2.2 Scope of VXML Grammars. 10 3.1 System Model . 18 3.2 Structure of Interface Sheet . 19 4.1 Example Html Node Tree. 22 4.2 HTML Parser - Example conversion . 23 4.3 Overall Process . ..