Macroblock-level rate control based on the linear RD model for H.264/AVC

The stability of the bit-rate is a desirable feature of compression systems. The paper presents the video rate control algorithm based on the linear model in the so-called ρ domain. To increase the compression rate accuracy, Quantization Parameter is selected after coding of a specified number of macroblocks. Moreover, the model is updated to correspond to the part of the frame remaining to be coded. The rate control algorithm is implemented in the H.264/AVC JM11 reference model. Testing results prove that the video encoder achieves a better stability of the bit-rate and higher quality compared to the original G12 algorithm applied in the JM11 software.