Auxiliary stream for optimizing memory access of video decoders

	Auxiliary stream for optimizing memory access of video decoders
	Liu Shaoli; Li Ling; Chen Yunji; Hu Weiwu
	2014
发表期刊	SCIENCE CHINA-INFORMATION SCIENCES
ISSN	1674-733X
卷号	57 期号:1
摘要	Due to the ever increasing resolution and frame rate of mainstream video sequences, memory access has become the main performance bottleneck of video decoding. To reduce the required off-chip memory, many decoders employ on-chip cache. However, they cannot distinguish whether a data block is reusable due to the lack of the information of undecoded Macro Blocks (MBs), thus often evicting reusable data from the cache and preserving non-reusable data in the cache, which will lead to a waste of off-chip memory bandwidth. In this paper, we manage to make full use of cache from a novel perspective, i.e., auxiliary bitstream. Concretely speaking, since the memory access behavior of video decoding is determined in video encoding, the encoder can pack the memory access behaviors of video decoding as auxiliary bitstream, which can inform the decoder whether a data block will be reused by future MBs. Hence, such an auxiliary stream can enable optimal management of cache. To effectively reduce the size of auxiliary bitstream, we propose an Auxiliary Prior Information Coding (APIC) method complying with the current video standards. For future video standards, we introduce a Super Block scan Order (SBO) for MB organization to further reduce the bitrate overhead of auxiliary bitstream. The above ideas are evaluated on a number of representative video sequences. The additional prior information can reduce the required off-chip memory bandwidth for motion compensation by over 35% (for a 60 kB cache), while only causing less than 2.3% bitrate increase for high definition (HD) videos.
关键词	MOTION COMPENSATION HIGH-PERFORMANCE HDTV DECODER ARCHITECTURE STANDARDS CHIP video decoding video coding memory access motion compensation auxiliary information
语种	英语
资助项目	[Strategic Priority Research Program of the Chinese Academy of Sciences] ; [National Natural Science Foundation of China] ; [National S&T Major Project of China] ; [National High-tech R&D Program of China (863)]
文献类型	期刊论文
条目标识符	http://119.78.100.204/handle/2XEOYT63/30845
专题	中国科学院计算技术研究所期刊论文_中文
作者单位	中国科学院计算技术研究所
第一作者单位	中国科学院计算技术研究所
推荐引用方式 GB/T 7714	Liu Shaoli,Li Ling,Chen Yunji,et al. Auxiliary stream for optimizing memory access of video decoders[J]. SCIENCE CHINA-INFORMATION SCIENCES,2014,57(1).
APA	Liu Shaoli,Li Ling,Chen Yunji,&Hu Weiwu.(2014).Auxiliary stream for optimizing memory access of video decoders.SCIENCE CHINA-INFORMATION SCIENCES,57(1).
MLA	Liu Shaoli,et al."Auxiliary stream for optimizing memory access of video decoders".SCIENCE CHINA-INFORMATION SCIENCES 57.1(2014).