Patent ID: 8107537
Filing Date: 2012-01-31
Classification: H04N

Abstract:
1. A method for one pass, picture layer, rate control for a video encoder that encodes a video stream that includes a series of pictures, said method including the steps of: determining the complexity of the pictures in a forward sliding window that covers a plurality of pictures including a current picture, calculating a target number of bits for each current picture using the complexity ratio of said current picture and the sum of the complexity of all pictures remaining in the current sliding window, the complexity of each particular picture being calculated using a linear rate quantization scale model, calculating a quantization parameter (QP) for each current picture using said calculated target number of bits and a quantization scale determined by said rate quantization scale model, controlling said encoder using said quantization parameter (QP), wherein said sliding window is moved by one picture each time that QP for a particular picture is calculated, wherein the plurality of pictures including the current picture corresponds to fifteen pictures, and the sliding window covers the fifteen pictures, the method further comprising: determining the complexity of each of the fifteen pictures in the forward sliding window, calculating a target number of bits for each current picture using the complexity ratio of said current picture and the sum of the complexity of all fourteen pictures remaining in the current sliding window, the complexity of each particular picture being calculated using a linear rate quantization scale model, calculating a quantization parameter (QP) for each current picture using said calculated target number of bits and a quantization scale determined by said rate quantization scale model, controlling said encoder using said quantization parameter (QP); and moving said sliding window by one picture each time said QP for a particular picture is calculated.