System and method of providing data in one of a plurality of digital formats using an active disk

摘要

A device is provided for storing signals in minimal format, which includes a controller for processing signals and a non-volatile storage medium. The device provides output signals in one of a plurality of digital formats. The output signals may be video signals, encrypted data, etc. In one embodiment, the device provides video signals in one of two digital video Standards, DV and MPEG-2, each Standard providing for discrete cosine transform (DCT) compressed signals which include macroblocks containing a plurality of DCT blocks. When raw video signals are received by the device, the DCT blocks are quantized according to one of the two quantization methods defined by the respective Standard, i.e., either DV or MPEG-2 and stored on the non-volatile storage medium in a minimal storage format consisting of DCT coefficients. Further, when signals are received in DV or MPEG-2 formats by the device for storage, such signals are decoded to obtain DCT coefficients and stored on storage medium in this minimal storage format. Upon a request for output of such stored signals, the controller selectively encodes the data in minimal storage format to either DV or MPEG-2 formats and outputs the encoded data to the requestor.