Moving picture coding and decoding method with replacement and temporal motion vectors
View Patent ↗A moving picture coding method includes: coding a coding target block using a motion vector; generating motion vector predictors; and coding the motion vector using one of the motion vector predictors generated in the generating of the motion vector predictors. In the generating of the motion vector predictors, a replacement vector which replaces a temporal motion vector predictor is added to the motion vector predictors when it is impossible to obtain the temporal motion vector predictor from a block which is included in a coded picture different from the coding target picture and corresponds to the coding target block.
1. A moving picture decoding method for performing inter prediction decoding on a decoding target block included in a decoding target picture, the moving picture decoding method comprising:
obtaining a temporal motion vector enable flag which indicates whether or not using a temporal motion vector predictor is enabled, the temporal motion vector predictor being from a block which is included in a decoded picture different from the decoding target picture and which corresponds to the decoding target block;
generating a plurality of motion vector predictors;
decoding a motion vector using one of the plurality of motion vector predictors generated in the generating; and
decoding the decoding target block using the motion vector decoded in the decoding of the motion vector,
wherein, in the generating, a motion vector having a motion quantity of 0 is generated when the temporal motion vector enable flag indicates that using the temporal motion vector predictor is not enabled, the motion vector being included, as a replacement vector which replaces the temporal motion vector predictor, in the plurality of motion vector predictors.
2. A moving picture decoding apparatus which performs inter prediction decoding on a decoding target block included in a decoding target picture, the moving picture decoding apparatus comprising:
an obtaining unit configured to obtain a temporal motion vector enable flag which indicates whether or not using a temporal motion vector predictor is enabled, the temporal motion vector predictor being from a block which is included in a decoded picture different from the decoding target picture and which corresponds to the decoding target block;
a motion vector predictor candidate generating unit configured to generate a plurality of motion vector predictors;
a motion vector decoder configured to decode a motion vector using one of the plurality of motion vector predictors generated by the motion vector predictor candidate generating unit; and
an image decoder configured to decode the decoding target block using the motion vector decoded by the motion vector decoder,
wherein the motion vector predictor candidate generating unit generates a motion vector having a motion quantity of 0 when the temporal motion vector enable flag indicates that using the temporal motion vector predictor is not enabled, the motion vector being included, as a replacement vector which replaces the temporal motion vector predictor, in the plurality of motion vector predictors.