Abstract
Picture coding is divided into several components, such as motion compensation, inter/intra-mode switching, DCT, VLC etc. Each component has been improved with only the component. There arises a problem that an interaction with other components or a total optimization is not be considered. Two components at distant location are especially difficult to be treated and the relation between them is not shown. In this report, from an analysis of coded bitstream, redundancy of coded bitstream is evaluated. The analysis gives some policies to improve coding performance of each component and to clarify coding relation between components. A method of random number analysis is proposed. Entropy, Markov entropy, sampled calculation, auto-correlation are used for measuring redundancy of coded bitstream. To clarify the measured results, a precision criterion is derived, which gives the necessary data amount for valid measuring. Examples show the entropy values are at least 0.9-0.85. This results indicates that re-encoding is possible.
