Methods of coding and decoding moving-picture signals, using self-resynchronizing variable-length codes

A method of coding a source signal representing a moving picture, said source signal having parts representing different picture areas and said picture areas being orginized into groups, said method comprising, for each group among said groups, the steps of:

• generating a start code for said group;
• generating, for each picture area in said group, header information designating a picture area type and designating whether coded picture data are present for said picture area, said picture area type indicating a coding format of said picture area;
• generating coded picture data for those picture areas designated in said header information as having coded picture data present, using a self-resynchronizing variable-length coding rule;
• and
• outputting said start code, followed by said header information for all picture areas in said group, then followed by said coded picture data.

A method of decoding a coded signal containing both fixed-length and variable-length codewords, in which all of said variable-length codewords are coded according to a single self-resynchronizing coding rule, and in which, among said codewords, there are start codes that begin segments of said coded signal pertaining to respective groups of picture areas, comprising the steps of:

• detecting one start code among said start codes;
• decoding codewords following said one start code;
• checking for errors in the codewords thus decoded;
• attempting to resynchronize according to said signal self-resynchronizing coding rule, if an error is recognized;
• storing subsequent codewords in a memory until a next start code is detected when resynchronization occurs after an error;
• and
• decoding contents of said memory.

A method of decoding a coded signal containing start codes, header information, and coded picture data, each of said start codes being followed by header information pertaining to one group of picture areas and to individual picture areas in said group of picture areas, then by coded picture data pertaining to the same group of picture areas, and said coded picture data being coded according to a self-resynchronizing variable-length coding rule, said method comprising the steps of:

• detecting one of said start codes;
• decoding the header information following said one of said start codes;
• storing the header information thus decoded in a memory;
• decoding said coded picture data while referring to the header information stored in said memory;
• checking for errors in the header information and coded picture data thus decoded;
• attempting to resynchronize according to said variable-length coding rule, if an error is recognized;
• storing subsequent coded picture data in said memory until a next start code is detected when resynchronization occurs after an error;
• and
• decoding the coded picture data stored in said memory while referring to the header information stored in said memory.