| 摘要 |
A video encoder includes: a restriction block identification unit that determines a valid prediction mode with a reference range not overlapping an unrefreshed region, for each size of a first sub-block, which is a unit for generating a prediction block, when a coding-target block in a refreshed region is to be encoded by intra prediction coding; and a coding mode determination unit that identifies a combination of the size of the first sub-block, the size of a second sub-block, which is a unit for application of a prediction mode, and a valid prediction mode with the smallest estimation value of the amount of code for encoding a third block, which is a unit for application of an intra prediction coding mode, as a combination to be used for intra prediction coding of the third sub-block. |
| 主权项 |
1. A video encoder that encodes a coding-target picture included in a video in an intra-refresh scheme, the video encoder comprising:
a restriction block identification unit that, when a coding-target block included in a refreshed region, which corresponds to a region through which a slice to which the intra-refresh is applied has traversed, in the coding-target picture is encoded in accordance with an intra-prediction coding mode in which a prediction block for the coding-target block is generated by using information on an encoded region in the coding-target picture and an error signal between the coding-target block and the prediction block is encoded, for each of a plurality of possible sizes of a first sub-block in the coding-target block, the first sub-block being a unit for generating the prediction block, among a plurality of prediction modes with different reference ranges of encoded pixels to be referred to in generating the prediction block for the first sub-block, determines a prediction mode with the reference range not overlapping an unrefreshed region, which corresponds to a region through which a slice to which the intra-refresh is applied has not traversed, as a valid prediction mode; a coding mode determination unit that
calculates, for each combination of a size of the first sub-block, a size of a second sub-block which includes the first sub-block and serves as a unit for application of the prediction mode, and the valid prediction mode, an estimation value of an amount of code when a third sub-block which includes the first sub-block and the second sub-block and serves as a unit for application of an intra prediction coding mode, is intra-prediction-encoded, anddetermines the combination of the size of the first sub-block, the size of the second sub-block, and the valid prediction mode with a smallest one of the estimation values, as an intra prediction mode; a prediction coding unit that generates coded data by encoding the third sub-block in accordance with the intra prediction mode; and an entropy coding unit that entropy-encodes the coded data. |
