Patent ID: 6977964

Claim:
A digital VTR for magnetically recording and replaying a digitally transmitted bit stream in a predetermined recording format, comprising: an input means receiving a bit stream, said bit stream including intra coded picture data and inter coded picture data representing encoded transformation coefficients and arranged in transport packets; data identification means for decoding and identifying header information of the input bit stream; data extracting means for extracting, from the input bit stream, a series of encoded data of image blocks as fast replay data used for fast replay, based on the decoded header information; decoding means for decoding the series of coded data of the input bit stream and for outputting a transformation coefficient belonging to the decoded data; coefficient counting means for counting the number of transformation coefficients; data reducing means for receiving the coefficient count number from the coefficient counting means and for controlling the data extracting means in such a way that the data length of the extracted, coded data of an integer number of image blocks is reduced to a data amount which can be recorded in K sync blocks in said predetermined format, wherein K is a positive integer; division number setting means, responsive to the bit stream input including a predetermined number M of transport packets as a unit, wherein M is an integer, wherein N sync blocks are related to the transport packets such that N is not equal to M, and wherein N is an integer; division means for dividing M transport packets into N sync blocks to form the recording format; header appending means for generating a first header for each of the M transport packets and appending the first header to each of the M transport packets; format forming means for forming N consecutive sync blocks from the data after the division of the bit stream; and recording means for recording the N consecutive sync blocks as normal reply data; said recording means recording, as the fast replay data, the extracted, coded data with the data length thereof having been reduced in specific areas for the K sync blocks.