Patent ID: 6031963
Filing Date: 2000-02-29
Classification: G11B,H04N

Abstract:
An encoding and decoding method, wherein a sub-picture, simultaneously reproducible with a main picture, is encoded into at least one sub-picture packet, said method comprising:converting said sub-picture into bit-mapped sub-picture data;preparing a spatial parameter for defining a display area of said sub-picture on a display area of the main picture;compressing said bit-mapped sub-picture data according to a predetermined compression technique to generate compressed pixel data;preparing display start time information for specifying a display start time of said sub-picture;preparing at least one display control sequence table for controlling a display of said sub-picture;preparing a sub-picture data unit header having size information, for identifying a size of a sub-picture data unit used to generate said sub-picture and being defined by contents of said at least one sub-picture packet, and position information, for identifying a position of said display control sequence table in said sub-picture data unit;combining the compressed pixel data and said display control sequence table with said sub-picture data unit header to generate a sub-picture data unit;generating a sub-picture data unit packet when a size of said sub-picture data unit exceeds a predetermined value;recording time stamp information at a header of said sub-picture data unit packet having a size exceeding the predetermined value or said sub-picture data unit having a size not more than the predetermined value, said time stamp information representing a playback start time of said sub-picture encoded into said at least one sub-picture packet;packing said sub-picture data unit packet having said time stamp information or packing said sub-picture data unit having said time stamp information to generate a data stream containing data from the packed sub-picture data unit and other data;separating the data of the packed sub-picture data unit from the data stream;disassembling the pack of the separated sub-picture data unit;extracting said time stamp information from the disassembled pack if the time stamp information is recorded at the disassembled pack;comparing the extracted time stamp information with time information provided by a system timer; andchecking one or more contents of said display control sequence table if the extracted time stamp information matches the time information from the system timer.