Various schemes pertaining to pre-encoding processing of a video stream with motion compensated temporal filtering (MCTF) are described. An apparatus determines a filtering interval for a received raw video stream having pictures in a temporal sequence. The apparatus selects from the pictures a plurality of target pictures based on the filtering interval, as well as a group of reference pictures for each target picture to perform pixel-based MCTF, which generates a corresponding filtered picture for each target picture. The apparatus subsequently transmits the filtered pictures as well as non-target pictures to an encoder for encoding the video stream. Subpictures of natural images and screen content images are separately processed by the apparatus.

Various schemes pertaining to pre-encoding processing of a video stream with motion compensated temporal filtering (MCTF) are described. An apparatus determines a filtering interval for a received raw video stream having pictures in a temporal sequence. The apparatus selects from the pictures a plurality of target pictures based on the filtering interval, as well as a group of reference pictures for each target picture to perform pixel-based MCTF, which generates a corresponding filtered picture for each target picture. The apparatus subsequently transmits the filtered pictures as well as non-target pictures to an encoder for encoding the video stream. Subpictures of natural images and screen content images are separately processed by the apparatus.

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 video decoding method, includes: reconstructing a syntax corresponding to at least one of a first block, a second block and a third block, wherein the first block is generated by dividing a frame for decoding, the second block corresponds to a unit of a prediction and is generated by dividing the first block, and the third block corresponds to a unit of transformation and is generated by dividing the first block in a tree structure; and reconstructing a prediction block corresponding to at least one of the first block, the second block and the third block.

A video decoding method, includes: reconstructing a syntax corresponding to at least one of a first block, a second block and a third block, wherein the first block is generated by dividing a frame for decoding, the second block corresponds to a unit of a prediction and is generated by dividing the first block, and the third block corresponds to a unit of transformation and is generated by dividing the first block in a tree structure; and reconstructing a prediction block corresponding to at least one of the first block, the second block and the third block.

A device implementing the subject video coding system may include at least one processor to determine an x-tap filter for horizontal interpolation of a N×M block. The processor further determines a y-tap filter for vertical interpolation of the N×M block, and encodes the N×M block using the x-tap filter and the y-tap filter. The value of x is proportional to N and the value of y is proportional to M.

Techniques to identify one or more candidate reference blocks used to generate a prediction block to encode a current coding block. The candidate reference blocks can be in the same layer as the current coding block or a different layer. In addition, the candidate reference blocks do not have to be co-located with the current coding block. Motion vectors and shift vectors can be used to identify the one or more candidate reference blocks. In addition, uniform and non-uniform weighting can be applied to the one or more candidate reference blocks to generate the prediction block. Accordingly, an encoder can determine and identify reference blocks to a decoder that can provide desirable rate-distortion cost.

An apparatus for coding video information according to certain aspects includes a memory and a processor. The memory unit is configured to store video information. The processor is configured to: obtain reference layer video information; upsample the reference layer video information in a first dimension to generate an intermediate output; constrain the intermediate output to a predetermined bit depth; and upsample the constrained intermediate output in a second dimension, wherein the second dimension is orthogonal to the first dimension.

An apparatus for coding video information according to certain aspects includes a memory and a processor. The memory unit is configured to store video information. The processor is configured to: obtain reference layer video information; upsample the reference layer video information in a first dimension to generate an intermediate output; constrain the intermediate output to a predetermined bit depth; and upsample the constrained intermediate output in a second dimension, wherein the second dimension is orthogonal to the first dimension.