tailieunhanh - Báo cáo hóa học: " Rate Control for H.264 with Two-Step Quantization Parameter Determination but Single-Pass Encoding"

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: Rate Control for with Two-Step Quantization Parameter Determination but Single-Pass Encoding | Hindawi Publishing Corporation EURASIP Journal on Applied Signal Processing Volume 2006 Article ID 63409 Pages 1-13 DOI ASP 2006 63409 Rate Control for with Two-Step Quantization Parameter Determination but Single-Pass Encoding Xiaokang Yang 1 YongminTan 1 and Nam Ling2 1 Institute of Image Communication and Information Processing Shanghai Jiao Tong University Shanghai 200030 China 2 Department of Computer Engineering Santa Clara University Santa Clara CA 95053-0566 USA Received 1 August 2005 Revised 27 June 2006 Accepted 16 July 2006 We present an efficient rate control strategy for in order to maximize the video quality by appropriately determining the quantization parameter QP for each macroblock. To break the chicken-and-egg dilemma resulting from QP-dependent ratedistortion optimization RDO in a preanalysis phase is conducted to gain the necessary source information and then the coarse QP is decided for rate-distortion RD estimation. After motion estimation we further refine the QP of each mode using the obtained actual standard deviation of motion-compensated residues. In the encoding process RDO only performs once for each macroblock thus one-pass while QP determination is conducted twice. Therefore the increase of computational complexity is small compared to that of the JM software. Experimental results indicate that our rate control scheme with two-step QP determination but single-pass encoding not only effectively improves the average PSNR but also controls the target bit rates well. Copyright 2006 Hindawi Publishing Corporation. All rights reserved. 1. INTRODUCTION MPEG-4 AVC is the latest international video coding standard developed by Joint Video Team JVT of ISO Motion Picture Expert Group and ITU-T Video Coding Expert Group 1-5 . As in other video standards such as MPEG-2 6 and 7 8 rate control remains as an open but important issue for AVC. A rate control scheme that is able to maximize the video .