Abstract: Methods, apparatus and computer program products are provided in which a set of valid motion vector values for encoding and decoding may depend on a reference picture used. A current block of a frame is selected for encoding, and a reference block for the current block is selected. On the basis of the selected reference block a reference type is determined. On the basis of the reference type and the reference block a motion vector for the current block is determined. Motion vector information is encoded and decoded on the basis of the determined motion vector.

Abstract: An apparatus for providing motion estimation for video encoding includes a selection element and a processing element. The selection element is configured to select a subset including less than all of candidate pixel locations from among a plurality of candidate pixel locations used for motion vector determination based on a relationship between a best candidate pixel location of a first level of accuracy and a best candidate pixel location of a second level of accuracy. The processing element is configured to process an input video sequence to determine a motion vector at the first level of accuracy, to refine the motion vector at the second level of accuracy, and to determine the motion vector at a third level of accuracy using only the subset of candidate pixel locations.

Abstract: There is disclosed an apparatus, a method and a computer program for video coding. The apparatus comprises a selector configured for selecting a pixel for prediction; a projection definer configured for determining a projection of said pixel to a set of reference pixels; and a prediction definer configured for selecting one or more reference pixels from said set of reference pixels on the basis of said projection, and using said selected one or more reference pixels to obtain a prediction value for said pixel to be predicted.

Abstract: There are disclosed various methods, apparatuses and computer program products for video decoding or encoding. In some embodiments for decoding a block that contains quantized residual coefficients based on at least two color channels of a video presentation or an image is received. A first quantization parameter and an offset defining a relationship between the first quantization parameter and a second quantization parameter for the block are obtained. The value of the second quantization parameter is determined by using the first quantization parameter and the offset. The residual samples are reconstructed by dequantizing the quantized residual coefficients using the second quantization parameter, if the block has been encoded by using a cross-channel residual coding mode.

Abstract: A method for motion compensated prediction, the method comprising determining a residual signal for at least one sample; determining if said residual signal is representing residual for samples in more than one channel; and if affirmative, applying said residual signal for at least a first sample in a first channel for generating a first reconstructed sample; and applying said residual signal for at least a second sample in a second channel for generating a second reconstructed sample.

Abstract: There is disclosed an apparatus, a method and a computer program for video coding. The apparatus comprises a selector configured for selecting a pixel for prediction; a projection definer configured for determining a projection of said pixel to a set of reference pixels; and a prediction definer configured for selecting one or more reference pixels from said set of reference pixels on the basis of said projection, and using said selected one or more reference pixels to obtain a prediction value for said pixel to be predicted.

Abstract: There are disclosed various methods, apparatuses and computer program products for video encoding and decoding. In some embodiments for encoding a block of samples is obtained for motion prediction (900). At least one translational base motion vector component for the block of samples is calculated by defining a prediction for said translational base motion vector component (902, 904). A first differential motion vector component using a first precision is defined (906). Said first differential motion vector component is added to said prediction for said translational base motion vector component. At least one higher order motion vector component is calculated by defining a prediction for said higher order motion vector component (908) and defining a second differential motion vector component using a second precision different from the first precision (910). Said second differential motion vector component is added to said prediction for said higher order motion vector component.

Abstract: A system and method for improving the coding efficiency of motion vector information in video coding. According to various embodiments, a list of motion vector predictor candidates is arranged according to predefined rules. Each motion vector also has a reference index associated with it. One of the motion vector candidates is then selected as a predictor based on predefined rules, or the selection is explicitly signaled in the bitstream. The reference index associated with the selected motion vector is used as a reference index for the current block. The reference index is predicted along with the motion vector. Such embodiments can improve the compression efficiency of modern video codecs.

Abstract: The invention relates to a method for encoding, a method for decoding, an apparatus, computer program products, an encoder and a decoder for video information. The motion vector for a block in a video image is predicted from a set of motion vector prediction candidates determined based on previously-coded motion vectors. A motion vector prediction candidate is included in the set based on the location of the block associated with the first spatial motion vector prediction candidate and in comparison with motion vector prediction candidates already in the set.

Abstract: Apparatuses, methods and computer programs are provided for utilizing motion prediction in video coding. A block of pixels of a video representation encoded in a bitstream is read, and a type of the block is determined. If the determining indicates that the block is a block predicted by using two or more reference blocks, a first reference pixel location in a first reference block is determined and a second reference pixel location in a second reference block is determined. The first reference pixel location is used to obtain a first prediction. The first prediction has a second precision, which is higher than the first precision. The second reference pixel location is used to obtain a second prediction, which also has the second precision. The first prediction and the second prediction are combined to obtain a combined prediction; and the precision of the combined prediction is reduced to the first precision.

Abstract: Various methods, apparatuses and computer program products for video encoding and decoding. In some embodiments a first picture having a first resolution on a first layer is encoded without inter-layer prediction; a second picture having a second resolution on a second layer is encoded without inter-layer prediction; a third picture having the second resolution on the second layer is encoded without inter-layer prediction and without temporally referencing to pictures prior to the second picture. Further, a corresponding indication is encoded. In some embodiments one or more indications are received to determine if a switching point, referring to a picture coded using inter-layer prediction, from the first layer to the second layer exists, and if so, pictures in the first layer prior to the switching point; pictures associated with the switching point; and pictures in the second layer after the switching point may be decoded.

Abstract: A system and method for improving the coding efficiency of motion vector information in video coding. According to various embodiments, a list of motion vector predictor candidates is arranged according to predefined rules. Each motion vector also has a reference index associated with it. One of the motion vector candidates is then selected as a predictor based on predefined rules, or the selection is explicitly signaled in the bitstream. The reference index associated with the selected motion vector is used as a reference index for the current block. The reference index is predicted along with the motion vector. Such embodiments can improve the compression efficiency of modern video codecs.

Abstract: The invention relates to a method for encoding, a method for decoding, an apparatus, computer program products, an encoder and a decoder for video information. The motion vector for a block in a video image is predicted from a set of motion vector prediction candidates determined based on previously-coded motion vectors. A motion vector prediction candidate is included in the set based on the location of the block associated with the first spatial motion vector prediction candidate and in comparison with motion vector prediction candidates already in the set.

Abstract: There is disclosed apparatuses, methods and computer programs for utilizing motion prediction in video coding. A block of pixels of a video representation encoded in a bitstream is read, and a type of the block is determined. If the determining indicates that the block is a block predicted by using two or more reference blocks, a first reference pixel location in a first reference block is determined and a second reference pixel location in a second reference block is determined. The first reference pixel location is used to obtain a first prediction. Said first prediction has a second precision, which is higher than the first precision. The second reference pixel location is used to obtain a second prediction, which also has the second precision. The first prediction and the second prediction are combined to obtain a combined prediction; and the precision of the combined prediction is reduced to the first precision.

Abstract: The invention relates to a method for decoding, comprising receiving a bitstream comprising encoded image data, forming from the bitstream in a computer memory a set of reference pixels having reference pixel values for intra-picture directional prediction, predicting a pixel value in a predicted image block (P) by intra-picture directional prediction by using values of one or more selected reference pixels (410, 420) in forming a predicted a pixel value, wherein the selected reference pixels (410, 420) are selected from a prediction direction with respect to the predicted pixel, and wherein the prediction direction between the reference pixel (410) and the predicted pixel can be a wide-angle prediction direction that forms an obtuse angle with top-left direction, repeating the pixel prediction for a number of pixels to form a predicted image block, and using the predicted image block (P) in decoding an image block from the bitstream to obtain a decoded image block.

Abstract: A method comprising: decoding, from a bitstream, a first encoded region of first picture into a first preliminary reconstructed region; forming a first reconstructed region from the first preliminary reconstructed region, wherein the forming comprises resampling and/or rearranging the first preliminary reconstructed region, wherein the rearranging comprises relocating, rotating and/or mirroring; and decoding at least a second region, wherein the first reconstructed region is used as a reference for prediction in decoding the at least second region and the second region either belongs to a second picture and is spatially collocated with the first reconstructed region or belongs to the first picture.

Abstract: The invention relates to a method for encoding, a method for decoding, an apparatus, computer program products, an encoder and a decoder for video information. The motion vector for a block in a video image is predicted from a set of motion vector prediction candidates determined based on previously-coded motion vectors. A motion vector prediction candidate is included in the set based on the location of the block associated with the first spatial motion vector prediction candidate and in comparison with motion vector prediction candidates already in the set.

Abstract: There is disclosed a method comprising receiving a set of coefficients; and determining whether a sign of a coefficient in the set of coefficients can be embedded in a bitstream. If the determining indicates that the sign of the coefficient in the set of coefficients can be embedded in the bitstream, an indication of the embedded sign is inserted into the bitstream. There is also disclosed a method comprising receiving a set of decoded coefficients; and determining whether a bitstream contains an indication of an embedded sign of a coefficient. If the determining indicates that the bitstream contains the indication of an embedded sign of a coefficient, the sign is determined on the basis of the decoded coefficients; and the sign of the coefficient is modified on the basis of the determined sign.

Abstract: There is disclosed an apparatus, a method and a computer program for video coding. The apparatus comprises a selector configured for selecting a pixel for prediction; a projection definer configured for determining a projection of said pixel to a set of reference pixels; and a prediction definer configured for selecting one or more reference pixels from said set of reference pixels on the basis of said projection, and using said selected one or more reference pixels to obtain a prediction value for said pixel to be predicted.

Abstract: There are disclosed various methods, apparatuses and computer program products for video encoding and decoding. In some embodiments for encoding a block of samples is obtained for motion prediction (900). At least one translational base motion vector component for the block of samples is calculated by defining a prediction for said translational base motion vector component (902, 904). A first differential motion vector component using a first precision is defined (906). Said first differential motion vector component is added to said prediction for said translational base motion vector component. At least one higher order motion vector component is calculated by defining a prediction for said higher order motion vector component (908) and defining a second differential motion vector component using a second precision different from the first precision (910). Said second differential motion vector component is added to said prediction for said higher order motion vector component.