| 摘要 |
<p>In many video encoding bit rate control models such as TMN8 and RHO domain, the distortion D has been described as a uniform weighted distortion, and therefore the distortion in each macroblock is introduced by uniformly quantising its DCT transform coefficients with a quantiser of step size Qstep. The TMN8 rate control uses a frame-layer rate control to select a target number of bits for the current frame, and a macroblock-layer rate control to select the values of the quantisation step sizes for the macroblocks. However, the distribution of the residual coding error does not conform to a uniform distribution but approximately to a Laplacian distribution. According to the invention an approximated but still easy-to-use Laplacian distribution model is calculated for the quantisation step size adaptation in the macroblock layer bit rate control.</p> |
