Abstract: There is provided a method of managing PMV candidates. The method comprises selecting a set of PMV candidates as a subset of the previously coded motion vectors. The method further comprises assigning a code value to each PMV candidate in the set of PMV candidates. The code values vary in length and are assigned to the PMV candidates in order of expected usage such that the PMV candidate having the highest expected usage has one of the shortest code values.

Abstract: Current deblocking filters are using the same filters with the same filtering strength irrespective of the block size and the size of the transform used. However, in the new video coding standards such as emerging HEVC the PU sizes can vary from 4 to 64 and the TU sizes can vary from 4 to 32. Therefore, filtering the same amount of pixels (e.g. two or three) from the block boundary for the block of size 4 can be excessive, while for the block size 32 it may not be enough, with the result that the boundary between two blocks is still visible. Hence, there is a need for an efficient deblocking filter control that can be used to reduce blocking artifacts at block boundaries and that does not have the above mentioned drawbacks. It is a general objective to provide an efficient deblocking filter control. Thus, the objective is solved by applying different filters for different block sizes such as CU, PU or/and TU sizes.

Abstract: A method of reducing blocking artifacts associated with pixels of a block boundary of an image. Pixel values of pixels from a first block and a neighboring block, being located on opposite sides of a block boundary, are evaluated. A first offset for the two pixels of each block located next to the block boundary is calculated, after which the first offset is compared to a first threshold value. If abs[first offset]<first threshold, the pixel values of consecutive pixels from the first block and the pixel values of consecutive pixels from the second block are modified by applying normal filtering on the respective pixels, while if instead abs[first offset]>=first threshold, the pixel values of consecutive pixels from the first block and the pixel values of consecutive pixels from the second block are modified by applying weak filtering or no filtering at all on the respective pixels.

Abstract: In a method of transcoding of a video bitstream by a transcoder arrangement, performing the steps of receiving (S10) a video bitstream with a predetermined input video format, receiving (S20) side information related to the video bitstream, the side information comprising at least one of mode or motion or in-loop filter information relating to at least one other predetermined video format for the video bitstream. Further, performing the steps of decoding (S40) the received side information to generate transcoding guiding information, and encoding (S50) a representation of the received video bitstream based at least on the generated transcoding guiding information, to provide a transcoded video bitstream with a predetermined output video format.

Abstract: A method of reducing blocking artifacts associated with consecutive pixels of a block boundary of an image, such as e.g. a video frame is provided. Pixels values of pixels selected from a first block and at least a neighboring block, being located on opposite sides of a block boundary are evaluated. A first offset for the two pixels of each block located next to the block boundary is calculated, after which the first offset is compared to a first threshold value.

Abstract: Blocking artifacts at a block boundary between a block and a neighboring block in a video frame are reduced by calculating an offset based on pixel values of pixels in a line of pixels in the block and based on pixel values of pixels in a corresponding line of pixels in the neighboring block. The offset is added to the pixel value of the pixel closest to the block boundary in the line of pixels and is subtracted from the pixel value of the pixel closest to the block boundary in the corresponding line of pixels. The resulting deblocking filter has good low-pass characteristics and is efficient for reducing blocking artifact.

Abstract: The present invention relates to a method and a transcoder arrangement of transcoding a bitstream representing an original video source from an input format to an output format. The method comprises the steps of receiving (S10) the bitstream with the input video format, wherein the input video format is a high fidelity format; and receiving (S20) side information related to said video bitstream. Said side information comprising at least: a video bitstream representing the original video source with a low fidelity input video format, coding parameters optimized based on knowledge of the original video source; transform coefficients, indicative of a residual between the original video source and a decoded version of the high fidelity format.

Abstract: Blocking artifacts at a block boundary between a block and a neighboring block in a video frame are reduced by calculating an offset based on pixel values of pixels in a line of pixels in the block and based on pixel values of pixels in a corresponding line of pixels in the neighboring block. The offset is added to the pixel value of the pixel closest to the block boundary in the line of pixels and is subtracted from the pixel value of the pixel closest to the block boundary in the corresponding line of pixels. The resulting deblocking filter has good low-pass characteristics and is efficient for reducing blocking artifact.

Abstract: In a motion estimation for a group of at least one image element in a frame of a video sequence, a global motion is determined between the frame and a reference frame. Uncovered groups present in an uncovered region of the frame are identified based on the determined global motion. The global motion is assigned as motion representation for these identified uncovered groups. The assigned motion representation is useful for constructing new frames in the sequence in a frame rate up-conversion.

Abstract: Video encoder and decoder and methods therein for transform skipped encoding and decoding of blocks of pixels. The methods comprises a modified use of an existing context model associated with transform coefficients, for deriving contexts for a bitmask indicating which residual values (i.e. not transform coefficients), in a transform skipped residual block, that are greater than one. The methods are applicable to video coding schemes such as HEVC.

Abstract: Methods and arrangements for video coding are provided. In one exemplary embodiment, a method performed by a video decoder may include decoding an encoded video block based on a single index corresponding to the encoded video block and a predetermined reference picture list to obtain a decoded video block. Further, the index may represent a combination of a reference mode and one or more reference pictures associated with the predetermined reference picture list.

Abstract: A scalable video coding method for coding a video sequence (10) results in a bit stream (20} partitionable into two layer representations (201, 2O2) of the video sequence (10). The second layer representation (2O2) has an enhanced resolution compared to the first layer representation (2O1.). The method includes generating (si) predictive coding parameters for the second layer using previously reconstructed pixels (14) in the second layer. The method further includes performing (s2) prediction for the first layer, using the predictive coding parameters and the previously reconstructed pixels (14) in the second layer, to generate a first layer prediction signal. The method further includes generating (s3) a first layer residual, based on the difference between the original image and the first layer prediction signal. The predictive coding parameters and the first layer residual are coded (s4) as the first layer representation (2O1). An encoder (30) and computer program are also provided.

Abstract: Methods and arrangements in video encoding and decoding entities. The methods and arrangements involve determining (804) the frequency of occurrence of a plurality of reference pictures associated with an obtained (802) set of blocks, which are neighbors of a block B. The methods and arrangements further involve selecting (806) a reference picture or combination of reference pictures having the highest determined frequency of occurrence to be a prediction, Cpred, of the reference picture or combination of reference pictures, C, to be used when encoding/decoding the block, B. The methods and arrangements further involve providing/obtaining (610,612, 808) an indication specifying whether the prediction, Cpred, corresponds to C, and when the prediction, Cpred, is indicated to correspond to C, the encoded block, Be, is decoded (812) based on the prediction Cpred.

Abstract: Methods and arrangements in video encoding and decoding entities. The methods and arrangements relate to the joint encoding of reference information associated with encoded video. The method and arrangement in a decoding entity relate to obtaining (402) a single syntax element associated with an encoded block Be, and identifying (404) a reference mode and one or more reference pictures based on the obtained syntax element. The method and arrangement further relate to-decoding (406) of the block Be based on the identified reference mode and one or more reference pictures, thus providing a decoded block, B, of pixels.

Abstract: A method of encoding an input video frame into an encoded video frame comprises the steps of disassembling the input video frame into a plurality of blocks of pixels. For each block being a current block, the method further comprises generating a corresponding predicted block from already reconstructed pixels, generating a residual block by subtracting the predicted block from the current block, generating a reconstructed block from the residual block and the predicted block, and generating the encoded video frame from the residual block The method further entails creating a local structure of reconstructed pixels in a region of the predicted block and aligning the predicted block with the local structure to produce an aligned predicted block, wherein the aligned predicted block is used in the steps of generating the residual block and generating the corresponding reconstructed block.

Abstract: Visible artifacts in a video stream of pictures with slices are reduced by having a separate maximum transform size for intra coding units in inter coded slices as compared to intra coding units in intra coded slices and/or inter coding units or by penalizing the usage of large transform size for such intra coding units in inter coded slices as compared to intra coding units in intra coded slices and/or inter coding units.

Abstract: A method, a filtering control device, a computer program and a computer program product for processing a first picture in a sample adaptive filtering procedure are disclosed. The first picture is reconstructed from video data. The filtering control device obtains an offset magnitude from the video data. The offset magnitude indicates a magnitude of a sample adaptive offset to be applied in the sample adaptive filtering procedure. The filtering control device obtains an offset sign from the video data. The offset sign indicates a sign of the sample adaptive offset. The filtering control device determines the sample adaptive offset based on the offset magnitude and the offset sign. Moreover, the filtering control device processes, in the sample adaptive filtering procedure, at least a portion of the first picture while applying the sample adaptive offset.

Abstract: An encoding method for encoding of images and corresponding decoding method is disclosed, as well as an encoder and a decoder. The encoding method comprises creating, in an encoder, a residual block from an original block and a prediction block which is an approximation of the original block, wherein the created residual block comprises residual block elements. The en-coding method further comprises re-ordering, in the encoder, the residual block elements within the residual block; and applying, in the encoder, a transform to the re-ordered residual block. By re-ordering the residual block elements prior to applying a transform, an improved efficiency of the encoding may be obtained.

Abstract: The present invention teaches a filter process used in intra or inter prediction of pixel blocks. A first, optionally interpolation, filter is applied in the first filter process to get filtered, optionally interpolated, pixel values. A differential filter and an adaptive gain are utilized in the second process for improving the prediction performance. The adaptivity of the gain can be made even on block basis, allowing a fine tuning of the pixel prediction and/or a fine tuning of pixel rotation and zooming. Alternatively, a combined one-step filter process using the interpolation filter, the differential filter and the adaptive gain is applied to the pixel values.

Abstract: A method and arrangement for prediction of pixel values in an image decoder. In an image decoder, a reference vector which is provided by an image encoder is provided 500. An initiation region of pixels is determined 502, which corresponds to a reference region of pixels at the image encoder. The initiation region is spatially displaced in relation to the prediction region according to the reference vector, and a part of the initiation region overlaps a part of the prediction region. Pixel values are assigned 504 to pixels of the prediction region, whose corresponding pixel values in the initiation region are known. Pixel values of the overlapping region of the initiation region are assigned 506 to the corresponding pixels in the prediction region, the pixel values being assigned 504.