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: New Complexity Scalable MPEG Encoding Techniques for Mobile Applications | EURASIP Journal on Applied Signal Processing 2004 2 236-252 2004 Hindawi Publishing Corporation New Complexity Scalable MPEG Encoding Techniques for Mobile Applications Stephan Mietens Philips Research Laboratories Prof. Holstlaan 4 NL-5656 AA Eindhoven The Netherlands Email Peter . de With LogicaCMG Eindhoven Eindhoven University of Technology . Box 7089 Luchthavenweg 57 NL-5600 MB Eindhoven The Netherlands Email Christian Hentschel Cottbus University of Technology Universitatsplatz 3-4 D-03044 Cottbus Germany Email Received 10 December 2002 Revised 7 July 2003 Complexity scalability offers the advantage of one-time design of video applications for a large product family including mobile devices without the need of redesigning the applications on the algorithmic level to meet the requirements of the different products. In this paper we present complexity scalable MPEG encoding having core modules with modifications for scalability. The interdependencies of the scalable modules and the system performance are evaluated. Experimental results show scalability giving a smooth change in complexity and corresponding video quality. Scalability is basically achieved by varying the number of computed DCT coefficients and the number of evaluated motion vectors but other modules are designed such they scale with the previous parameters. In the experiments using the Stefan sequence the elapsed execution time of the scalable encoder reflecting the computational complexity can be gradually reduced to roughly 50 of its original execution time. The video quality scales between 20 dB and 48 dB PSNR with unity quantizer setting and between dB and dB PSNR for different sequences targeting 1500 kbps. The implemented encoder and the scalability techniques can be successfully applied in mobile systems based on MPEG video compression. Keywords and phrases MPEG encoding scalable algorithms .
