A reliability enhanced video storage architecture in hybrid SLC/MLC NAND flash memory

摘要

Video-based applications have been widely used in embedded mobile devices. In such devices, NAND flash memory chip is normally used as the storage media to store videos. To enlarge the capacity of NAND flash memory, MLC (multi-level cell) technology is widely adopted with low storage reliability compared with the classical SLC (single-level cell) technology. Thus, the inherent features of NAND flash memory will significantly affect the storage reliability of video files. In this paper, we propose a reliability enhanced MPEG video storage architecture (REVSA) in hybrid SLC/MLC storage systems. In this architecture, the video stream is reconstructed as the key cluster and the non-key cluster according to the importance of video restoration. The key cluster is stored in SLC blocks to ensure the reliability, while the non-key cluster is stored in MLC blocks to utilize its capacity. To achieve this, we introduce a new layer in the storage hierarchy called video bit-stream analyzer, which includes a segmentation pipeline and a merging pipeline for MPEG video stream to build clusters and merge them to original video stream. We conducted experiments in a hybrid SLC/MLC storage system to store the car driving videos. The experimental results show that the proposed scheme can significantly improve the storage reliability of the MPEG video files and prolong the lifetime of the storage system.