| 摘要 |
This system contains a hybrid coder which codes the incoming data of a video picture block by block. At the receiver end, a hybrid decoder reverses the coding steps of the hybrid coder. The incoming blocks of a video picture are, among other things, transformed by a transformation unit (T) and quantised in a quantiser (Q). To make the system optimally adaptable to transmission bit rates of between 64 kbit/s and 2 Mbit/s, a structuring unit (SE) is provided which combines several blocks, which represent a coherent section of a video picture, to form a macroblock. To each macroblock, it assigns a macroattribute which shows which characteristics are considered to be identical for all part-blocks of the microblock and which are not. Such characteristics include, for example, information on the movement vector of each part-block which, for example, can be equal for all part-blocks. <??>If a separate macroattribute (NON) is used, there is no characteristic which is considered to be equal for all part-blocks of a macroblock, instead, the characteristics are allocated to each part-block itself. <??>If necessary, the macroblocks themselves, in turn, are treated like part-blocks, that is to say combined to form even larger units. This results in a particularly effective coding during the transmission of still pictures. <IMAGE> |
