VARIABLE LENGTH CODER, VARIABLE LENGTH DECODER, PICTURE CODER AND PICTURE DECODER

摘要

PURPOSE:To attain a high speed real time comparator coping with a moving picture with high picture quality by means of a simple processing circuit by providing an event memory to a coder side and placing write priority thereon. CONSTITUTION:Coefficient data received by a variable length coding section 8 is converted into an event by an event generating section 100. The event generating section 100 sets a block end identifier EOB bit, and the event is inserted to the EOB after the stage of an event memory and the time required for event insertion is absorbed by the event memory 120. When a write clock from the generating section 100 is inputted to the event memory, the write of the event memory has priority over an event memory read request from a control circuit 200 and a read enable signal is outputted only when no write is implemented. The read enable signal is inputted to the control circuit 200 to inform it that event memory read is kept waiting. The read from the event memory 120 is started by a block start signal and the event corresponding to one block is read and subject to variable length coding.