CPC H04N 19/577 (2014.11) [H04N 19/105 (2014.11); H04N 19/159 (2014.11); H04N 19/176 (2014.11); H04N 19/46 (2014.11); H04N 19/59 (2014.11)] | 2 Claims |
1. A video decoding apparatus comprising:
a parameter decoding circuit configured to decode a first flag indicating whether or not a weighted prediction information is present in a picture header, a second flag indicating whether or not a weighted prediction is applied to B slices, a first syntax element for deriving weight coefficients, and a second syntax element indicating a number of entries in at least reference picture list 1;
a prediction parameter derivation circuit configured to derive inter prediction parameters;
a motion compensation circuit configured to generate interpolation images based on the inter prediction parameters and a reference picture; and
a weighted prediction circuit configured to derive the weight coefficients by using the first syntax element and generate a prediction image by using the interpolation images and the weight coefficients,
wherein the parameter decoding circuit decodes a third syntax element indicating a number of weights signaled for entries in the reference picture list 1 based on the first flag and the second flag,
the weighted prediction circuit sets a variable NumWeightsL1 indicating the number of weights signaled for entries in the reference picture list 1 to be equal to 0 in a case that the third syntax element is not decoded, and
the weighted prediction circuit sets the weight coefficient for the reference picture list 1 to be an exponential value of the first syntax element of 2 in a case that the value of the variable NumWeightsL1 is equal to 0.
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