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 A Multiple-Window Video Embedding Transcoder Based on Standard | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2007 Article ID 13790 17 pages doi 2007 13790 Research Article A Multiple-Window Video Embedding Transcoder Based on AVC Standard Chih-Hung Li Chung-Neng Wang and Tihao Chiang Department of Electronics Engineering National Chiao-Tung University 1001 Ta-Hsueh Road Hsinchu 30010 Taiwan Received 6 September 2006 Accepted 26 April 2007 Recommended by Alex Kot This paper proposes a low-complexity multiple-window video embedding transcoder MW-VET based on AVC standard for various applications that require video embedding services including picture-in-picture PIP multichannel mosaic screensplit pay-per-view channel browsing commercials and logo insertion and other visual information embedding services. The MW-VET embeds multiple foreground pictures at macroblock-aligned positions. It improves the transcoding speed with three block level adaptive techniques including slice group based transcoding SGT reduced frame memory transcoder RFMT and syntax level bypassing SLB . The SGT utilizes prediction from the slice-aligned data partitions in the original bitstreams such that the transcoder simply merges the bitstreams by parsing. When the prediction comes from the newly covered area without slice-group data partitions the pixels at the affected macroblocks are transcoded with the RFMT based on the concept of partial reencoding to minimize the number of refined blocks. The RFMT employs motion vector remapping MVR and intra mode switching IMS to handle intercoded blocks and intracoded blocks respectively. The pixels outside the macroblocks that are affected by newly covered reference frame are transcoded by the SLB. Experimental results show that as compared to the cascaded pixel domain transcoder CPDT with the highest complexity our MW-VET can significantly reduce the processing complexity by 25 times and retain the rate-distortion performance close to the CPDT. At certain
