| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve the problem that there has been a case in which a direct mode cannot be applied effectively before depending on a block. <P>SOLUTION: Information indicating whether a backward reference frame set by the default can be utilized in the direct mode is provided to a decoder. Moreover, a switching procedure to a compensation method applicable when a collocated block has no forward motion vector which can be effectively used and the compensation method are provided to the decoder. Thus, it is possible to clearly judge whether the reference frame can be used in the direct mode. Furthermore, when the frame number has no time information, it is possible to effectively send the information indicating the relationship between the reference frame and the current frame. Moreover, by the substitution mode of the present invention and its switching procedure, it is possible to improve the prediction performance when the direct mode cannot be applied. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
