| 主权项 |
1. An encoding and decoding apparatus, comprising:
an encoding apparatus which encodes, in a first bitstream, first last position information indicating a horizontal position and a vertical position of a last non-zero coefficient in a predetermined order from among a plurality of coefficients within a first current block to be encoded in a first picture; and a decoding apparatus which decodes second last position information indicating a horizontal position and a vertical position of a last non-zero coefficient in a predetermined order from among a plurality of coefficients within a second current block to be decoded in a second picture, wherein the encoding apparatus includes:
a binarizer which binarizes a horizontal component of the first last position information and a vertical component of the first last position information into a first binary signal and a second binary signal, respectively, the horizontal component indicating the horizontal position of the last non-zero coefficient within the first current block, the vertical component indicating the vertical position of the last non-zero coefficient within the first current block;an arithmetic encoder which encodes a first partial signal and a second partial signal respectively into an encoded first partial signal and an encoded second partial signal, by first arithmetic encoding, and encodes a third partial signal and a fourth partial signal respectively into an encoded third partial signal and an encoded fourth partial signal, by second arithmetic encoding different from the first arithmetic encoding, the first partial signal being a part of the first binary signal, the second partial signal being a part of the second binary signal, the third partial signal being another part of the first binary signal, the fourth partial signal being another part of the second binary signal; andan arranger which arranges the encoded first partial signal, the encoded second partial signal, the encoded third partial signal, and the encoded fourth partial signal, in this order in the first bitstream, and wherein the decoding apparatus includes:
an obtainer which obtains a second bitstream including a fifth partial signal, a sixth partial signal, a seventh partial signal, and an eighth partial signal, in this order;an arithmetic decoder which performs first arithmetic decoding on the fifth partial signal and the seventh partial signal, respectively, to obtain a decoded fifth partial signal and a decoded seventh partial signal, and performs second arithmetic decoding on the sixth partial signal and the eighth partial signal, respectively, to obtain a decoded sixth partial signal and a decoded eighth partial signal, the second arithmetic decoding being different from the first arithmetic decoding; anda deriver which derives a horizontal component of the second last position information from the decoded fifth partial signal and the decoded seventh partial signal, and derives a vertical component of the second last position information from the decoded sixth partial signal and the decoded eighth partial signal, the horizontal component indicating the horizontal position of the last non-zero coefficient within the second current block, the vertical component indicating the vertical position of the last non-zero coefficient within the second current block. |
