Method for encoding and decoding moving picture signals

Abstract

A method for encoding and decoding digital moving picture signals which can decode subframes appropriately in relation to time if a part of a bit stream is missing or an error occurs in the bit stream, and can suppress degradation of a reproduced picture if decoding of a subframe including a picture in motion in relation to time becomes unfeasible. In the method for encoding and decoding digital moving picture signals of this invention, information for one frame is encoded correspondingly to a spatial hierarchy of a frame, subframes and blocks. A subframe time position number and a subframe space number are attached to an identifier of each of the subframe, thereby resuming appropriate decoding of the subframes immediately after a trouble if an error occurs. The subframe identifiers are placed at a certain interval in the bit stream so as to give a smaller size to a subframe including a block which is in motion and difficult to be encoded, thereby suppressing degradation of a reproduced picture if decoding of the subframe becomes unfeasible.

1. A method for encoding digital motion picture signals of a frame, comprising the steps of:
 dividing said frame into plural blocks each including N×M pixels;  
 forming a subframe composed of a set of said blocks, said subframe being a unit to be encoded;  
 setting an identifier to said subframe to identify said subframe; and  
 specifying a frame to which said subframe belongs by adding to said identifier , the time position information representing an order of displaying said subframe;  
 encoding said time position information along with said subframe, and  
 multiplexing said encoded time position information and a bit stream of said encoded subframe to transmit said encoded time position information and said bit stream.  
 
     
     
       2. A method for encoding digital motion picture signals of a frame, comprising the steps of:
 dividing said frame into plural blocks each including N×M pixels;    forming a subframe composed of a set of said blocks, said subframe being a unit to be encoded; and    varying the number of said blocks included in said subframe according to a quantity of information generated by encoding each block to vary a spatial size of each of said subframes included in each frame.    
     
     
       3. A method for encoding digital motion picture signals of a frame, comprising the steps of:
 dividing said frame into plural blocks each including N×M pixels;    forming a subframe composed of a set of said blocks, said subframe being a unit to be encoded;    setting an identifier to said subframe to identify said subframe;    specifying a frame to which said subframe belongs by adding to said identifier time position information representing an order of displaying said subframe;    encoding said time position information along with said subframe, and    multiplexing said encoded time position information and a bit stream of said encoded subframe to transmit said encoded time position information and said bit stream; and    varying the number of said blocks included in said subframe according to a quantity of information generated by encoding each block to vary a spatial size of each of said subframes included in each frame.    
     
     
       4. The method for encoding digital motion picture signals of a frame according to  claim 2 , wherein each of said subframes included in said frame has an equal sum of quantities of generated information of said blocks included in said subframe. 
     
     
       5. The method for encoding digital motion picture signals of a frame according to  claim 3 , wherein each of said subframes included in said frame has an equal sum of quantities of generated information of said blocks included in said subframe. 
     
     
       6. A method for encoding and decoding digital motion picture signals of a frame, comprising the steps of:
 dividing said frame into plural blocks each including N×M pixels;    forming a subframe composed of a set of said blocks, said subframe being a unit to be encoded;    setting an identifier to said subframe to identify said subframe;    specifying a frame to which said subframe belongs by adding to said identifier time position information representing an order of displaying said subframe;    encoding said time position information along with said subframe;    multiplexing said encoded time position information and a bit stream of said encoded subframe to transmit said encoded time position information and said bit stream; and    decoding each of said subframes appropriately in relation to time by decoding and using said time position information to form said frame to said digital moving picture signals.    
     
     
       7. A method for encoding and decoding digital motion picture signals of a frame, comprising the steps of:
 dividing said frame into plural blocks each including N×M pixels;    forming a subframe composed of a set of said blocks, said subframe being a unit to be encoded;    varying the number of said blocks included in said subframe according to a quantity of information generated by encoding each block to vary a spatial size of each of said subframes included in each frame; and    decoding each of said subframes to form said first of said digital moving picture signal.    
     
     
       8. A method for encoding and decoding digital motion picture signals of a frame, comprising the steps of:
 dividing said frame into plural blocks each including N×M pixels;    forming a subframe composed of a set of said blocks, said subframe being a unit to be encoded,    setting an identifier to said subframe to identify said subframe;    specifying a frame to which said subframe belongs by adding to said identifier time position information representing an order of displaying said subframe;    encoding said time position information along with said subframe;    multiplexing said encoded time position information and a bit stream of said encoded subframe to transmit said encoded time position information and said bit stream;    varying the number of said blocks included in said subframe according to a quantity of information generated by encoding each block to vary a spatial size of each of said subframes included in each frame; and    decoding said subframe appropriately in relation to time by decoding and using said time position information to form said frame of said digital moving picture signal.    
     
     
       9. The method for encoding and decoding digital motion picture signals of a frame according to  claim 7 , wherein each of said subframes included in said frame has an equal sum of quantities of generated information of said blocks included in said subframe. 
     
     
       10. The method for encoding and decoding digital motion picture signals of a frame according to  claim 8 , wherein each of said subframes include din said frame has an equal sum of quantities of generated information of said blocks included in said subframe. 
     
     
       11. The method for encoding digital motion picture signals of a frame according to  claim 1 , wherein said step of adding time position information comprises adding the time information to each subframe of said frame. 
     
     
       12. The method for encoding digital motion picture signals of a frame according to  claim 11 , further comprising the step of maintaining substantially constant a quantity of information generated for each subframe within said frame thereby to vary spatial dimensions represented by each said subframe. 
     
     
       13. The method for encoding digital motion picture signals of a frame according to  claim 1 , further comprising the step of maintaining substantially constant a quantity of information generated for each subframe within said frame thereby to vary spatial dimensions represented by each said subframe. 
     
     
       14. The method for encoding and decoding digital motion picture signals of a frame according to  claim 6 , wherein said step of adding time position information comprises adding the time information to each subframe of said frame. 
     
     
       15. The method for encoding digital motion picture signals of a frame according to  claim 14 , further comprising the step of maintaining substantially constant a quantity of information generated for each subframe within said frame thereby to vary spatial dimensions represented by each said subframe. 
     
     
       16. The method for encoding digital motion picture signals of a frame according to  claim 6 , further comprising the step of maintaining substantially constant a quantity of information generated for each subframe within said frame thereby to vary spatial dimensions represented by each said subframe.