Picture encoding method and apparatus and picture decoding method and apparatus

Abstract

A picture encoding method includes receiving an input video signal, encoding the video signal using a reference picture signal to generate a video code stream, encoding the reference picture signal to generate a reference picture code stream, and multiplexing the video code stream with the reference picture code stream to generate an output code stream.

1 . A picture decoding apparatus comprising: 
 an input unit configured to receive an input code stream containing a video code stream obtained by encoding a video signal and a motion-compensated reference picture code stream obtained by encoding a reference picture signal;    a first decoding unit configured to decode the motion-compensated reference picture code stream contained in the input code stream to generate a first reference picture signal; and    a second decoding unit configured to decode the video code stream contained in the input code stream by selectively using one of a second reference picture signal obtained from a previous picture signal and the first reference picture signal to generate a playback picture signal the second decoding unit including a frame memory which stores the playback picture signal as the second reference picture signal, and a motion compensation unit configured to subject one of the second reference picture signal read out from the frame memory and the first reference picture signal to motion compensation.    
   
   
       2 . A picture decoding method comprising: 
 receiving an input code stream containing a video code stream obtained by encoding a video signal and a motion-compensated reference picture code stream obtained by encoding a reference picture signal;    decoding the motion-compensated reference picture code stream contained in the input code stream to generate a first reference picture signal;    decoding the video code stream contained in the input code stream by selectively using one of a second reference picture signal obtained from a previous picture signal and the first reference picture signal to generate a playback picture signal;    storing in a frame memory the playback picture signal as the second reference picture signal; and    motion-compensating one of the second reference picture signal read out from the frame memory and the first reference picture signal.    
   
   
       3 . A computer readable storage medium storing instructions of a computer program which when executed by a computer results in performance of steps comprising: 
 receiving an input code stream containing a video code stream obtained by encoding a video signal and a motion-compensated reference picture code stream obtained by encoding a reference picture signal;    decoding the motion-compensated reference picture code stream contained in the input code stream to generate a first reference picture signal;    decoding the video code stream contained in the input code stream by selectively using one of a second reference picture signal obtained from a previous picture signal and the first reference picture signal to generate a playback picture signal;    storing in a frame memory the playback picture signal as the second reference picture signal; and    motion-compensating one of the second reference picture signal read out from the frame memory and the first reference picture signal.    
   
   
       4 . A computer system comprising: 
 means for receiving an input code stream containing a video code stream obtained by encoding a video signal and a motion-compensated reference picture code stream obtained by encoding a reference picture signal;    means for decoding the motion-compensated reference picture code stream contained in the input code stream to generate a first reference picture signal;    means for decoding the video code stream contained in the input code stream by selectively using one of a second reference picture signal obtained from a previous picture signal and the first reference picture signal to generate a playback picture signal;    means for storing in a frame memory the playback picture signal as the second reference picture signal; and    means for motion-compensating one of the second reference picture signal read out from the frame memory and the first reference picture signal.