Method and system for locating digital contents in a recorded digital file without knowing its encoding format

摘要

A method and system locating contents of a recorded digital audio/video file without knowing its encoding format. The method and system can be implemented on a disk drive, e.g., magnetic or optical, or on any suitable storage mechanism. A bus timer is used for periodically generating a cycle count in synchronization with isochronous packets that are also on the bus. The disk drive stores both the current cycle count and the current digital packet together on a storage media, e.g., magnetic or optical or memory array, etc. When the cycle count value reaches a predetermined number of increments, a seconds measure is incremented thereby updating a minute and hour measure (as necessary). The updated hour/minute/second value is stored in an entry of an index table along with the logical block address (LBA) of the currently stored data packet. This continues until the file is completely recorded. Retrieval of a particular hour/minute/second of the file can then be readily accomplished by referencing the index table and obtaining the appropriate LBA without requiring knowledge of the particular encoding format used by the file. The index table is stored in the file system and associated with the particular file (track). The recorded cycle counts can be used as an offset to obtain a particular frame when frame accuracy is required. In one embodiment, the IEEE 1394 bus is used which generates one cycle count every 125 us. The drive maintains its own file system and can send data on the bus and store information without requiring continuous operational control from an intelligent device.