Patent ID: 9667989
Date: 2017-05-30
CPC Classifications: H04N

Claim:
1. A moving picture decoding device that decodes a bitstream in which moving pictures are coded by partitioning a first block, which is obtained by partitioning each picture of the moving pictures into predetermined sizes, into one or a plurality of second blocks, the device comprising: a decoding unit configured to extract a differential quantization parameter of the second block by decoding the bitstream; a predictive quantization parameter deriving unit configured to derive a predictive quantization parameter of the second block using quantization parameters of a third block adjacent to the left of the second block and a fourth block adjacent to the top of the second block; and a quantization parameter generation unit configured to generate a quantization parameter of the second block by adding the differential quantization parameter of the second block and the predictive quantization parameter of the second block, wherein the predictive quantization parameter deriving unit sets the quantization parameter of the third block as a first quantization parameter when the third block is at a position not beyond a boundary of the first block, sets a quantization parameter of a fifth block decoded before the second block as the first quantization parameter when the third block is at a position beyond the boundary of the first block so as to set the first quantization parameter having a non-zero value regardless of the position for the boundary of the first block, sets the quantization parameter of the fourth block as a second quantization parameter when the fourth block is at a position not beyond the boundary of the first block, sets the quantization parameter of the fifth block as the second quantization parameter when the fourth block is at a position beyond the boundary of the first block so as to set the second quantization parameter having a non-zero value regardless of the position for the boundary of the first block, and derives the predictive quantization parameter of the second block using both the first and second quantization parameters regardless of the position of the third block or the fourth block, or both the third and fourth blocks, with respect to the boundary of the first block.