Data Extraction from DVR Hard Disks via DBR Table Analysis
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Solution Overview
Problem
Embedded security devices, such as digital video recorders, face challenges in recovering and extracting data due to data loss and incompatibility issues with different manufacturers and hard disk types, particularly in unused areas, leading to unrecognizable abnormal incident recordings.
Innovation Solution
A method involving analysis of the DBR table to determine data block management tables and video stream headers, allowing for the extraction of video data based on time continuity and channel uniformity, ensuring complete data recovery from embedded security devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If data is stored in DVR hard disk using traditional methods, then video recording function is achieved, but data loss occurs in unused areas and deleted videos cannot be extracted
Solution Approach 1:
The patent segments the hard disk data structure into distinct components: DBR tables, data blocks, and management tables. By analyzing and extracting information from each segment separately (DBR table contains number of data blocks, size, and start position; management tables contain offset positions and channel information), the system can reconstruct video data even when parts are deleted or corrupted, thereby improving data recovery capability while addressing information loss
Solution Approach 2:
The patent performs preliminary analysis of the DBR table and management tables to establish the data structure framework before actual video extraction. By pre-identifying the number of data blocks, their sizes, start positions, and channel information, the system prepares the necessary structural information in advance, enabling effective recovery of lost video data from unused areas
2Adaptability or versatility
If different manufacturers and types of hard disks are used, then device compatibility is improved, but video stream header incompatibility occurs
Solution Approach 1:
The patent creates a universal data extraction methodology that works across different manufacturers and hard disk types by focusing on the common DBR table and management table structures. The extraction algorithm is designed to be manufacturer-agnostic, recognizing video stream headers through standardized field analysis (offset position, channel information, time information) rather than manufacturer-specific formats, thereby achieving both broad compatibility and reliable video stream recognition
Solution Approach 2:
The patent adapts to different hard disk types by dynamically adjusting extraction parameters based on the analyzed DBR table information. The system reads the actual number of data blocks, block sizes, and start positions from each specific hard disk's DBR table, then modifies the extraction process accordingly. This parameter-driven approach allows the same extraction algorithm to reliably handle video streams from various manufacturers and hard disk configurations
3Duration of action of moving object
If embedded system runs continuously for long time, then monitoring coverage is improved, but machine errors occur and data becomes unrecognizable
Solution Approach 1:
The patent creates a conceptual copy of the original video data structure through the DBR table and management tables, which store metadata about the video streams (number of blocks, sizes, positions, channel information). Even when the original video data becomes corrupted or unrecognizable due to long-term operation, this structural copy remains intact and can be used to reconstruct and recover the video data, maintaining reliability despite extended monitoring duration
Data Source
AI summary
A method of data analysis and extraction for embedded security devices and belongs to the data recovery field, includes: Analyzing the DBR table of the first sector of a disk, the DBR table records the number of data blocks, the size of each data block, and the start position information of the first data block on a hard disk; Determining the management table of the first data block based on its position and size as recorded in the DBR table, the management table records the offset position, channel and time information of each data stream; Finding the header of the video stream called as video header based on the video stream information recorded in the management table of the data block, the video header records the tag header and time information of video decoding.