Image decoding apparatus for decoding a target block by referencing information of an already decoded block in a neighborhood of the target block

摘要

To provide an image decoding apparatus that suppresses overhead of parallel processing to improve parallelization efficiency and reduce circuit costs, while solving neighboring macroblock dependencies. The image decoding apparatus (100) includes first and second decoding circuits (101, 102) having a transfer unit that transfers right neighborhood information or left neighborhood information, and first and second transfer completion detection units (104, 105) that respectively detect whether or not the left neighborhood information or the right neighborhood information has been transferred to the first and second decoding circuits (101, 102). Each of the first and second decoding circuits (101, 102) decodes a decoding target macroblock positioned at an edge of a region, when the transfer of the left neighborhood information or the right neighborhood information is detected. A boundary line between regions is orthogonal to a decoding direction corresponding to an order in which macroblocks adjacent to each other are sequentially decoded.

主权项

1. An image decoding apparatus that decodes a coded picture composed of blocks, on a block-by-block basis, said image decoding apparatus comprising:
a division unit configured to divide a coded stream including the coded picture into a plurality of divided coded streams; a plurality of decoding units configured to decode, in parallel, images of regions in the coded picture that are each included in a different one of the plurality of divided coded streams and associated with a different one of said plurality of decoding units, by repeating decoding of a decoding target block by referencing information on an already decoded block in a neighborhood of the decoding target block as neighborhood information; a transfer unit configured to transfer, for each of said plurality of decoding units, neighborhood information that is to be referenced by said decoding unit and is generated by an other one of said plurality of decoding units, from said other decoding unit to said decoding unit as transfer target neighborhood information; and a detection unit configured to detect, for each of said plurality of decoding units, whether or not the transfer target neighborhood information that is to be referenced when decoding a decoding target block positioned at an edge of a region associated with said decoding unit has been transferred to said decoding unit, wherein each of said plurality of decoding units is configured to decode the decoding target block positioned at the edge of the region associated with said decoding unit, when said detection unit detects that the transfer target neighborhood information has been transferred to said decoding unit, wherein a boundary line between the regions is orthogonal to a decoding direction corresponding to an order in which blocks adjacent to each other are sequentially decoded, wherein said plurality of decoding units include a first decoding unit and a second decoding unit, wherein said transfer unit is configured to transfer the transfer target neighborhood information generated by said first decoding unit to said second decoding unit and to transfer the transfer target neighborhood information generated by said second decoding unit to said first decoding unit by (i) transferring the transfer target neighborhood information generated by said first decoding unit to a first memory bank, (ii) transferring the transfer target neighborhood information generated by said second decoding unit to a second memory bank, and (iii) performing bank switching between the first memory bank and the second memory bank to enable (a) the transfer target neighborhood information generated by said first decoding unit to be shared by said second decoding unit and (b) the transfer target neighborhood information generated by said second decoding unit to be shared by said first decoding unit, and wherein said detection unit is configured to (i) detect that the transfer target neighborhood information generated by said first decoding unit has been transferred to said second decoding unit when the transfer target neighborhood information generated by said first decoding unit is stored into the first memory bank and (ii) detect that the transfer target neighborhood information generated by said second decoding unit has been transferred to said first decoding unit when the transfer target neighborhood information generated by said second decoding unit is stored into the second memory bank.