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: Efficient Video Transcoding from to Standard with Enhanced Rate Control | Hindawi Publishing Corporation EURASIP Journal on Applied Signal Processing Volume 2006 Article ID 83563 Pages 1-15 DOI ASP 2006 83563 Efficient Video Transcoding from to AVC Standard with Enhanced Rate Control Viet-Anh Nguyen and Yap-Peng Tan School of Electrical Electronic Engineering Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Received 11 August 2005 Revised 25 December 2005 Accepted 18 February 2006 A new video coding standard AVC has been recently developed and standardized. The standard represents a number of advances in video coding technology in terms of both coding efficiency and flexibility and is expected to replace the existing standards such as and MPEG-1 2 4 in many possible applications. In this paper we investigate and present efficient syntax transcoding and downsizing transcoding methods from to AVC standard. Specifically we propose an efficient motion vector reestimation scheme using vector median filtering and a fast intraprediction mode selection scheme based on coarse edge information obtained from integer-transform coefficients. Furthermore an enhanced rate control method based on a quadratic model is proposed for selecting quantization parameters at the sequence and frame levels together with a new frame-layer bit allocation scheme based on the side information in the precoded video. Extensive experiments have been conducted and the results show the efficiency and effectiveness of the proposed methods. Copyright 2006 Hindawi Publishing Corporation. All rights reserved. 1. INTRODUCTION The presence of various efficient video coding standards has resulted in a large number of videos produced and stored in different compressed forms 1 . These coding standards compress videos to meet closely the constraints of their target applications such as available transmission bandwidth desired spatial or temporal resolution error resilience and so forth. Consequently videos compressed for
