Patent ID: 6381274
Filing Date: 2002-04-30
Classification: H04N

Abstract:
An apparatus for encoding first input picture data representing a succession of pictures each composed of plural blocks, the apparatus comprising:means for detecting an activity of the first input picture data for every block; means for generating information of an accumulation transition in an amount of a first code data in response to the detected activity for every block; means for calculating a code amount accumulation transition value from the accumulation transition information and a predetermined target code amount for every block, the predetermined target code amount being defined with respect to every picture; means for delaying the first input picture data into second input picture data by a predetermined time interval corresponding to a given number of successive pictures; means for quantizing the second input picture data into second quantization-resultant data in response to a variable quantization width; means for encoding the second quantization-resultant data into second code data of a variable length code for every block; means for detecting an actual amount of the second code data for every block; means for calculating an error between the code amount accumulation transition value and the detected actual amount of the second code data for every block; and means for controlling the variable quantization width in response to the calculated error for every block to maintain an actual amount of the second code data substantially at the target code amount for every picture.