Patent ID: 7512321

Claim:
A video recording/playback system for recording and playback of video data received, comprising: a memory which receives and stores video data which consists of sets of main data and sub data falling under different categories, the sets of main data and sub data being associated and sequenced along time axis wherein in a set of main data and sub data an ID code and substitute data are embedded in advance, said ID code identifying said set of main data and sub data, said substitute data being associated with said sub data, and the same ID code as assigned to said main data is assigned to said sub data; a playback unit which reads out main data and sub data from said memory and renders video contents of these data; and a controller which, when said main data stored in said memory is rendered, detects an ID code assigned to said main data, compares the detected ID code with an ID code assigned to said sub data stored in said memory and judges whether said sub data associated with said main data under rendering has already been read from said memory and its video rendered and, unless said detected ID code assigned to said main data agrees with said ID code assigned to said sub data stored in said memory, regards said sub data video as not having been rendered and changes substitute data embedded in said main data and associated in advance with said sub data into video data and incorporates said substitute data into said main data and makes said video data render when said main data is rendered.