摘要 |
The invention relates to a video encoding method applied to a sequence of video frames and generating a coded bitstream in which each data item is described by means of a bitstream syntax allowing any decoder to recognize and decode all the segments of the content of said bitstream. This method includes a predicting step, based on a prediction technique using a motion compensation operation, and a subtracting step, based on a subtraction of said predicted frame from the current one, and the motion compensation operation leads to motion vectors with horizontal and vertical components (MVx, MVy). These components have to be encoded differentially by using predictions (Px, Py) of said components and, in fact, only the differences (dx, dy) between the components and their predictions (Px, Py) are therefore encoded. According to the invention, said syntax includes an additional flag indicating that said differences (dx, dy) are present, or not, in the generated coded bitstream, and will have therefore to be decoded, or not, at the decoding side. |