tailieunhanh - Báo cáo hóa học: " Research Article Transcoding-Based Error-Resilient Video Adaptation for 3G Wireless Networks"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Transcoding-Based Error-Resilient Video Adaptation for 3G Wireless Networks | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2007 Article ID 39586 13 pages doi 2007 39586 Research Article Transcoding-Based Error-Resilient Video Adaptation for 3G Wireless Networks Sertac Eminsoy 1 Safak Dogan 2 and Ahmet M. Kondoz2 1 NEC Electronics Europe GmbH Cygnus House Sunrise Parkway Linford Wood Milton Keynes Buckinghamshire MK14 6NP UK 2I-Lab Centre for Communication Systems Research CCSR University of Surrey Guildford GU2 7XH Surrey UK Received 2 October 2006 Revised 19 February 2007 Accepted 13 May 2007 Recommended by Ming-Ting Sun Transcoding is an effective method to provide video adaptation for heterogeneous internetwork video access and communication environments which require the tailoring . repurposing of coded video properties to channel conditions terminal capabilities and user preferences. This paper presents a video transcoding system that is capable of applying a suite of error resilience tools on the input compressed video streams while controlling the output rates to provide robust communications over error-prone and bandwidth-limited 3G wireless networks. The transcoder is also designed to employ a new adaptive intra-refresh algorithm which is responsive to the detected scene activity inherently embedded into the video content and the reported time-varying channel error conditions of the wireless network. Comprehensive computer simulations demonstrate significant improvements in the received video quality performances using the new transcoding architecture without an extra computational cost. Copyright 2007 Sertac Eminsoy et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION The success of the Internet and mobile systems has motivated the development of various enhanced-capacity fixed and wireless networking