H.264視訊編碼標準提出SP/SI 畫面來達到無損串流切換。然而， SP/SI畫面必須先在原本的串流中設定切換點，因此通常無法達成即時切換的效果。若欲設定多個切換點，整體編碼效率將因而受到影響。本論文提出基於H.264編碼標準之動態串流切換，這個新的編碼機制能夠達成即時無損串流切換,且能夠運用於多位元率串流與多視角串流，達到視訊的調適性和視角的自由選擇性。我們將一張畫面分成移動補償畫面和冗餘畫面，利用SP/SI的概念各自獨立編碼。對於多視角視訊，利用不同視訊畫面間的關係，減少資料大小，利用SIFT演算法來預估整個畫面的位移，並且利用直方圖比對的方法，降低不同視角間的顏色差異，提升編碼效益。實驗結果顯示，我們所提出的方法在動態串流切換有良好的編碼表現結果。

The SP-frame in H.264 facilitates the drift-free bit-stream switching. However, the switching points have to be periodically inserted into the bit-stream in advance and thus the low-delay bit-stream switching may not be achieved. If many switching points are assigned, the coding performance of SP/SI frames will be affected. In this research, we consider the dynamic bit-stream switching in H.264/AVC, which can be applied on both the multi-rate coding and multi-view coding for video adaption and free-viewpoint switching. A novel coding scheme is proposed to enable the drift-free switching at any frame. We separate a frame into two components, i.e. the motion compensated part and residuals, which are encoded independently by employing the concept of SP/SI frames. For interview coding, the inter-correlation from the different views is further utilized. We apply SIFT to estimate the global displacement and the histogram matching algorithm to correct the color inconsistence in different scenes so that the negative effects of secondary SP frames can be reduced. Experimental results show that our scheme has good performance in the free bit-stream switching.

[1] Marta Karczwicz and Ragip Kurceren, Member, IEEE, “The　SP-and SI-Frames Design for H.264/AVC, ” IEEE Transactions on Circuits and Systems for Video Technology, vol.13, no.7, 2003 , P.637 - 644
[2] Yifeng Liu; Chuangbai Xiao; Ligang Zhen; “Research in Codec Optimization and the application of SP-frame in H.264/AVC,” IASP 2009, P.212-215
[3] Marta Karczwicz and Ragip Kurceren ” Synchronization-Predictive coding for video compression: The SP frames design for JVT/H.26L,” Image Processing. ICIP 2002 , vol.2, II-497 - II-500
[4] Xiaoyan Sun; Shipeng Li; Feng Wu; Jacky Shen; Wen Gao; “The improved SP frame coding technique for the JVT STamdard ,” Image Processing. ICIP 2003, vol.2, III - 297-300
[5] Wai-tian Tan; Bo Shen; “methods to improve coding efficiency of sp frames, ” Image Processing. ICIP 2006, P. 1361 - 1364
[6] Yui-Lam Chan, Tak-Piu Ip, Ki-Kit Lai, Chang-Hong Fu and Wan-Chi Siu , “A New Dual-bitstream Video Streaming System with VCR Functionalities Using SP/SI-frames ,” Journal of Signal Processing Systems, 2011, vol. 62, no.3, P.403-414
[7] Chia-Wen Lin , Cheng-Po Chang ,“Rate-Distortion Optimized Quantization under Storage Constraints for Dynamic Bitstream Switching Using H.264 SP-Frames,” CVGIP 2005
[8] K.-K., Lai; Yui-Lam Chan; Wan-Chi Siu; “Quantized transform-domain motion estimation for SP-frame coding in viewpoint switching of multiview video,” IEEE Transactions on Circuits and Systems for Video Technology 2010 ,vo1.20, no.3 , P.365 - 381
[9] Xiaoyan Sun; Feng Wu; Shipeng Li; Wen Gao; Ya-Qin Zhang; “Seamless switching of scalable video bitstreams for efficient streaming,” IEEE Transaction on Multimedia 2004 , vol.6, no.2, P.291 - 303
[10] Ju-Hun Nam; Byeong-Doo Choi; Sung-Jea Ko; “Dynamic bitstream switching using progressive S-frames for scalable video transmission ,”IEEE Transaction on Consumer Electronics 2008 , vol.54, no.4, P.1996 - 2002
[11] Shih-Ming Hsu; Chia-Wen Lin; I-Hsien Lee; “A New Seamless Bitstream Switching Scheme for H.264 Video Adaptation with Enhanced Coding Performance ,” Image Processing. ICIP 2006, P. 873 - 876
[12] Xiaoyan Sun; Feng Wu; Shipeng Li; Guobin Shen; Wen Gao; “Drift-free switching of compressed video bitstreams at predictive frames,” IEEE Transactions on Circuits and Systems for Video Technology 2006 ,vol.16, no.5 , P.565 - 576
[13] Xiaosong Zhou , C.-C. Jay Kuo ,”Efficient bit stream switching of H.264 coded video,” SPIE 2005 , vol.5909, 590911-1
[14] Xiaosong Zhou , C.-C. Jay Kuo , “Efficient and Flexible Video Streaming for H.264/AVC ,”
[15] Xiaoyan Sun; Shipeng Li; Feng Wu; Guobin Shen; Wen Gao; “Efficient and flexible drift-free video bitstream switching at predictive frames,” ICME 2002, vol.1 ,P.541-544
[16] Setton, E.; Girod, B.; “Rate-Distortion Analysis and Streaming of SP and SI Frames,” IEEE Transactions on Circuits and Systems for Video Technology 2006 ,vol.16, no.6 , P.733 - 743
[17] Setton Eric , Girod Bernd, “Video streaming with SP and SI frames,” VCIP 2005
[18] Xun Guo; Yan Lu; Wen Gao; Qingming Huang; “Viewpoint Switching in Multiview Video Streaming,” ISCAS 2005 ,vol.4 P.3471 - 3474
[19] Fecker, U.; Barkowsky, M.; Kaup, A.; “Histogram-Based Prefiltering for Luminance and Chrominance Compensation of Multiview video,” IEEE Transactions on Circuits and Systems for Video Technology 2008 ,vol.18, no.9 , P.1258 - 1267
[20] Doutre, C.; Nasiopoulos, P.; “Color Correction Preprocessing For Multiview Video Coding ,” IEEE Transactions on Circuits and Systems for Video Technology 2009 ,vol.19, no.9 , P.1400 - 1406
[21] Liu, Yi; Wang, Yongfang; Zhang, Zhaoyang; “Color Correction Method Based on Histogram Segmentation for Multiview video,” CCWMC 2009 , P.539 - 542
[22] Feng Wu, Shipeng Li , “ The core experiment on the SP frame coding,” JVT-B112, Joint Video Team(JVT) of ISO/IEC MPEG & ITU-T VCEG, Geneva , Feb. 2002
[23] X. Sun , F. Wu , S. Li , W. Gao, Y. –Q. Zhang , “Improved SP coding technique,” JVT-B097, Joint Video Team(JVT) of ISO/IEC MPEG & ITU-T VCEG, Geneva , January 2002
[24] X. Sun , F. Wu , S. Li , W. Gao, Y. –Q. Zhang , “The Improved JVT-B097 SP coding scheme,” JVT-C114, Joint Video Team(JVT) of ISO/IEC MPEG & ITU-T VCEG, Fairfax , May 2002
[25] Marta Karczwicz and Ragip Kurceren, “A Proposal for SP-frames,” document VCEG-L-27, ITU-T Video Coding Experts Group Meeting, Eibsee, Germany, 09-12 January 2001