Patent ID: 8032012

Claim:
A data processor for editing a content that has been written on a medium, the content being stored in a first file as a data stream including multiple packets of the same packet size, a file system for accessing data on a cluster size basis having been established on the medium, the data processor comprising: a receiving section, which receives an instruction on a partial deletion range including the beginning of the first file; and a media control section for generating a second file by deleting data, the size of which is an integral number of times as large as the least common multiple of the cluster size and the packet size, from the beginning of the first file within the partial deletion range, wherein the data stream includes a plurality of playback units, each of which has a plurality of pictures and one or more decoding units that need to be decoded from a base picture, and wherein the media control section writes a first data size value, representing a size as measured from the beginning of the second file, from which the data has already been deleted, through the first playback unit in the data stream of the second file, on the medium.