Patent ID: 7016407

Claim:
A method for determining a bit rate need of a plurality of variable rate video channels in a video encoder, comprising the steps of: processing video data from a current picture in each respective channel to determine at least a spatial activity and a temporal activity thereof; determining a bit rate demand for each current picture according to the associated spatial activity and temporal activity; determining whether characteristics of the current pictures exist for adjusting the initial bit rate demand thereof, and if so, adjusting the initial bit rate demand, determining an overall available bit rate for transmitting the current pictures in a multiplexed data stream; determining, in an initial iteration, an initial allocated bit rate for each current picture according to a ratio of bit rate demand thereof to a sum of the bit rate demands from each current picture; determining a bit rate surplus or deficit between the overall available bit rate and a sum of the initial allocated bit rates; and adjusting, in at least one successive iteration, the initial allocated bit rate for at least some of the current pictures according to the surplus or deficit and a ratio of bit rate demand thereof to a sum of the bit rate demands thereof.