Patent ID: 6411738
Filing Date: 2002-06-25
Classification: H04N

Abstract:
A variable bitrate video coder characterized in that it comprises:(a) a coding branch, including in series at least a quantization circuit and a variable length circuit; (b) a prediction branch, including in series at the output of said quantization device at least an inverse quantization device and a prediction sub-system and defining by subtraction the signal to be coded by said coding branch; (c) a control circuit provided for carrying out the implementation of the following operations: a coding operation of a video sequence with quantization stepsize to generate a bitstream including frames; a prediction operation for an estimation of the quantization stepsize to code the bitstream according to a specified target bitrate; at least one repetition of said operations; a controlling operation for modifying the quantization stepsize based on comparing if a total number of bits utilised during the coding operation matches said target bitrate.