Impact of video parameters on the DCT coefficient distribution for H.264-like video coders

We examine the impact of various encoding parameters on the distribution of the DCT coefficients for H.264-like video coders. We model the distribution of the frame DCT coefficients using the most common Laplacian and Cauchy distributions. We show that the resolution, the quantization levels and the coding type have significant impact on the accuracy of the Laplacian and Cauchy distribution based models. We also show that the transform kernel (4× 4 vs 8× 8) has little impact. Moreover, we show that for the video sources that have little temporal or spatial detail, such as flat regions, the distribution of the frame DCT coefficients resembles a Laplacian distribution. When the video source exhibits more detail, such as texture and edges, the distribution of the frame DCT coefficients resembles a Cauchy distribution. The correlation between the details of the video source to the two probability distributions can be used to further improve the estimation of the distribution of the frame DCT coefficients, by using a classification based approach.