Apparatus for encoding and decoding header data in picture signal transmission

Abstract

A picture decoding method and apparatus for encoding a video signal. The method includes performing an encoding process on the video signal to generate a bit stream compatible with MPEG 1 moving picture video standard. The method further includes controlling the encoding process so as to generate the bit stream which includes, in a previous picture header, an extension start code indicating the beginning of extension data added when a picture header includes control data that is newly added in MPEG 2 standard format and the extension data, and does not include, in a current picture header, the extension start code and the extension data.

1 - 3 . (canceled) 
     
     
         4 . A picture decoding method, executed by a processor, for decoding a bit stream, the bit stream being compatible with MPEG1 standard, the method comprising the steps of:
 performing a decoding process on the bit stream;   detecting, in a current picture header of the bit stream, the presence of an extension start code indicating the beginning of extension data added in a picture header of the bit stream when the picture header includes control data that is newly added in MPEG2 standard; and   controlling the decoding process so as to decode the bit stream in a current picture layer using a picture start code indicating a start point of the picture layer, a picture coding type of the current picture header, and the extension data of a previous picture header of the bit stream in case the presence of the extension start code is not detected in the current picture header of the bit stream.   
     
     
         5 . A picture decoding apparatus for decoding a bit stream, the bit stream being compatible with MPEG1 standard, the apparatus comprising:
 means for performing a decoding process on the bit stream;   means for detecting, in a current picture header of the bit stream, the presence of an extension start code indicating the beginning of extension data added in a picture header of the bit stream when the picture header includes control data that is newly added in MPEG2 standard; and   means for controlling the decoding process so as to decode the bit stream in a current picture layer using a picture start code indicating a start point of the picture layer, a picture coding type of the current picture header, and the extension data of a previous picture header of the bit stream in case the presence of the extension start code is not detected in the current picture header of the bit stream.   
     
     
         6 . A picture decoding apparatus for decoding a bit stream, the bit stream being compatible with MPEG1 standard, the apparatus comprising:
 a decoding unit that performs a decoding process on the bit stream;   a detection unit that detects, in a current picture header of the bit stream, the presence of an extension start code indicating the beginning of extension data added in a picture header of the bit stream when the picture header includes control data that is newly added in MPEG2 standard; and   a controller that controls the decoding process so as to decode the bit stream in a current picture layer using a picture start code indicating a start point of the picture layer, a picture coding type of the current picture header, and the extension data of a previous picture header of the bit stream in case the presence of the extension start code is not detected in the current picture header of the bit stream.