A method for coding a video implemented in an encoder or a decoder, comprising: determining control point motion vectors, CPMVs, for a block according to affine inter-prediction, according to a preselected affine motion model, the block being an affine block; performing motion compensation for the block using a pixel-based motion vector field according to values of the CPMVs, upon fulfilling at least one of the following conditions: A) for a predefined size of a sub-block of M×M, during processing of one line, respectively, of the sub-block the number of lines of the reference picture is less than N, where N is an integer and N is larger than 2.

A method is provided to better detect a scene change to provide a prediction to an encoder to enable more efficient encoding. The method uses a Motion Compensated Temporal Filter (MCTF) that provides motion estimation and is located prior to an encoder. The MCTF provides a Motion Compensated Residual (MCR) used to detect the scene change transition. When a scene is relatively stable, the MCR score is also relatively stable. However, when a scene transition is in process, the MCR score behavior changes, Algorithmically, the MCR score is used by comparing the sliding mean of the MCR score to the sliding median. This comparison highlights the transition points. In the case of a scene cut, the MCR score exhibits a distinct spike. In the case of a fade or dissolve, the MCR score exhibits a transitional period of degradation followed by recovery. By implementing the above detection using the MCR, the location of the I-pictures in the downstream encoding process can be accurately determined for the encoder.

A method is provided to better detect a scene change to provide a prediction to an encoder to enable more efficient encoding. The method uses a Motion Compensated Temporal Filter (MCTF) that provides motion estimation and is located prior to an encoder. The MCTF provides a Motion Compensated Residual (MCR) used to detect the scene change transition. When a scene is relatively stable, the MCR score is also relatively stable. However, when a scene transition is in process, the MCR score behavior changes, Algorithmically, the MCR score is used by comparing the sliding mean of the MCR score to the sliding median. This comparison highlights the transition points. In the case of a scene cut, the MCR score exhibits a distinct spike. In the case of a fade or dissolve, the MCR score exhibits a transitional period of degradation followed by recovery. By implementing the above detection using the MCR, the location of the I-pictures in the downstream encoding process can be accurately determined for the encoder.

The present invention relates to an image encoding and decoding technique, and more particularly, to an image encoder and decoder using unidirectional prediction. The image encoder includes a dividing unit to divide a macro block into a plurality of sub-blocks, a unidirectional application determining unit to determine whether an identical prediction mode is applied to each of the plurality of sub-blocks, and a prediction mode determining unit to determine a prediction mode with respect to each of the plurality of sub-blocks based on a determined result of the unidirectional application determining unit.

The present invention relates to an image encoding and decoding technique, and more particularly, to an image encoder and decoder using unidirectional prediction. The image encoder includes a dividing unit to divide a macro block into a plurality of sub-blocks, a unidirectional application determining unit to determine whether an identical prediction mode is applied to each of the plurality of sub-blocks, and a prediction mode determining unit to determine a prediction mode with respect to each of the plurality of sub-blocks based on a determined result of the unidirectional application determining unit.

The present invention relates to an image encoding and decoding technique, and more particularly, to an image encoder and decoder using unidirectional prediction. The image encoder includes a dividing unit to divide a macro block into a plurality of sub-blocks, a unidirectional application determining unit to determine whether an identical prediction mode is applied to each of the plurality of sub-blocks, and a prediction mode determining unit to determine a prediction mode with respect to each of the plurality of sub-blocks based on a determined result of the unidirectional application determining unit.

The present invention relates to an image encoding and decoding technique, and more particularly, to an image encoder and decoder using unidirectional prediction. The image encoder includes a dividing unit to divide a macro block into a plurality of sub-blocks, a unidirectional application determining unit to determine whether an identical prediction mode is applied to each of the plurality of sub-blocks, and a prediction mode determining unit to determine a prediction mode with respect to each of the plurality of sub-blocks based on a determined result of the unidirectional application determining unit.

A subblock-based coding of transform coefficient blocks of the enhancement layer is rendered more efficient. To this end, the subblock subdivision of the respective transform coefficient block is controlled on the basis of the base layer residual signal or the base layer signal. In particular, by exploiting the respective base layer hint, the subblocks may be made longer along a spatial frequency axis transverse to edge extensions observable from the base layer residual signal or the base layer signal.

A subblock-based coding of transform coefficient blocks of the enhancement layer is rendered more efficient. To this end, the subblock subdivision of the respective transform coefficient block is controlled on the basis of the base layer residual signal or the base layer signal. In particular, by exploiting the respective base layer hint, the subblocks may be made longer along a spatial frequency axis transverse to edge extensions observable from the base layer residual signal or the base layer signal.

An example device for coding video data is configured to determine that a block of the video data includes a plurality of sub-blocks, each of the sub-blocks having respective motion information referring to respective reference blocks in a reference picture in a memory, determine a single reference block of the reference picture, the single reference block including each of the respective reference blocks, wherein determining the single reference block comprises: determine four corner sub-blocks of the block included in the plurality of sub-blocks; and determine the single reference block according to the respective motion information for the four corner sub-blocks such that corners of the single reference block correspond to corners of the respective reference blocks of the four corner sub-blocks, retrieve data of the single reference block from the reference picture, and predict the sub-blocks from the respective reference blocks using the data of the single reference block.