Abstract: One exemplary embodiment presents a method of decoding a group of image elements in a frame of an encoded video sequence. The method comprises determining an intra-prediction mode for the group of image elements, and providing a first prediction of the group of image elements according to the determined intra-prediction mode. The method further comprises determining a location identifier identifying a location of a decoded version of another group of image elements in a frame of the video sequence, and providing a second prediction of the group of image elements using the determined location identifier.

Abstract: A pre-processing of a pixel in a picture comprises determining, based on a minimum color component value for the pixel, whether a default processing chain is used to derive a luma component value, a first subsampled chroma component value and a second subsampled chroma component value or whether an auxiliary processing chain is used to derive at least one of the luma component value, the first subsampled chroma component value and the second subsampled chroma component value. The pre-processing improves the visual quality of pictures but at a low cost with regard to extra processing time.

Abstract: A deblocking filtering control involves deciding whether to apply deblocking filtering to sample values in a sample block in a picture and in a neighboring sample block in the picture based on i) whether illumination compensation is enabled for sample prediction values in a first prediction block in a reference picture for said sample block and/or ii) whether illumination compensation is enabled for sample prediction values in a second prediction block in said reference picture or another reference picture for said neighboring sample block. The sample block and the neighboring sample block are separated in the picture by a block boundary. This decision to apply deblocking filtering based on whether illumination compensation is enabled reduces blocking artefacts that may otherwise arise in certain pictures of a video sequence.

Abstract: The present invention relates to an encoder, transcoder and methods thereof. A transcoder embodiment involves transcoding a bitstream representing an original video source from an input video format to an output video format. An encoder embodiment involves providing transform coefficients in side information related to an encoded video bitstream.

Abstract: A pixel value of a pixel in a picture of a video sequence is modified by a weighted combination of the pixel value and at least one spatially neighboring pixel value in a filtering. The filtering depends on a pixel distance between the pixel and a neighboring pixel and on a pixel value difference between the pixel and a neighboring pixel value of the neighboring pixel. The filtering is controlled by a spatial parameter and a range parameter. At least one of the spatial parameter and the range parameter depends on at least one of a quantization parameter, a quantization scaling matrix, a transform width, a transform height, a picture width, a picture height and a magnitude of a negative filter coefficient used as part of inter/intra prediction. The embodiments provide a deringing filtering to combat ringing artifacts during video coding.

Abstract: A first filter decision value is calculated for a block of pixels in a video frame based on pixel values of pixels in a first line of pixels in the block. A second filter decision value is also calculated for the block based on pixel values of pixels in a corresponding first line of pixels in a neighboring block in the video frame. The first filter decision value is used to determine how many pixels in a line of pixels in the block to filter relative to a block boundary between the block and the neighboring block. The second filter decision value is used to determine how many pixels in a corresponding line of pixels in the neighboring block to filter relative to the block boundary.

Abstract: A QP offset value is calculated for a chroma component of a pixel in a picture of a video sequence based on a reference QP value and a factor that depends on a difference between a capture color space for the pixel and an encoded color space for the pixel. A QP value is then calculated for the chroma component based on the reference QP value reduced by the QP offset value. The calculation of QP values for chroma components based on the factor that depends on the difference between capture and encoded color spaces improves the chroma quality in an efficient way in particular for HDR and WCG video.

Abstract: A pixel value of a pixel in a picture of a video sequence is modified by a weighted combination of the pixel value and at least one spatially neighboring pixel value in a filtering. The filtering depends on a pixel distance between the pixel and a neighboring pixel and on a pixel value difference between the pixel and a neighboring pixel value of the neighboring pixel. The filtering is controlled by a spatial parameter and a range parameter. The spatial parameter depends on at least one of a width and a height of a transform block, and on at least one of a prediction type of a block of pixels in the picture, a picture type of the picture, and a slice type of a slice in the picture.

Abstract: The present invention relates to an encoder, transcoder and methods thereof. A transcoder embodiment involves transcoding a bitstream representing an original video source from an input video format to an output video format. An encoder embodiment involves providing transform coefficients in side information related to an encoded video bitstream.

Abstract: A pixel pre-processing comprises subsampling a linear color in a first color space to obtain a subsampled linear color in the first color space. A first transfer function is applied to the subsampled linear color in the first color space to obtain a subsampled non-linear color in the first color space. A first color transform is applied to the subsampled non-linear color in the first color space to obtain a subsampled first non-linear chroma component value and/or a subsampled second non-linear chroma component value in a second color space. A non-linear luma component value in the second color space is derived for the pixel, which together with the subsampled non-linear chroma component values represent a color the pixel. The pre-processing reduces chroma artifacts that may otherwise occur when chroma subsampling is performed following application of the first transfer function and the first color transform.

Abstract: Delta quantized coefficients of a pixel block in a picture in a first representation of a video sequence are encoded based on information derived from estimated quantized coefficients for the pixel block. The delta quantized coefficients represent a difference between actual quantized coefficients of the pixel block derived by encoding at least a portion of the picture in the first representation of the video sequence and the estimated quantized coefficients. The estimated quantized coefficients represent a difference between a reconstructed block of a corresponding picture in a second representation of the video sequence and a prediction block obtained based on intra mode information and/or inter motion information derived by encoding the picture in the first representation of the video sequence.

Abstract: There are provided mechanisms for encoding a picture of a video sequence in a video bitstream. The picture comprises pixels wherein each pixel has a color value comprising at least one color component value. The method comprises determining a frequency distribution of the color component values of the at least one color component. The method comprises determining at least one quantization parameter for coding of transform coefficients for the at least one color component based on the determined frequency distribution of the color component values. The method comprises encoding the determined at least one quantization parameter.

Abstract: According to one aspect the present invention relates to a method for a video encoder. The method comprises providing (601) to a transcoder a first bitstream representing a video sequence with a first format, creating (602) a second bitstream representing transcoding information indicative of a transcoding method that should be used by the transcoder for transcoding the video sequence from the first format to a second format, and providing (603) to the transcoder the second bitstream.

Abstract: It is presented a method for encoding a video frame of a piece of video content. The method is performed in an encoder device and comprises the steps of: dividing the video frame into a set of non-overlapping regions, wherein the set comprises at least one region; assigning each region, in the set of regions, to a separate processing unit; encoding, in each processing unit, picture data of the respective region; collecting progress data from each processing unit, the progress data indicating progress of the encoding of the respective region; and dividing a particular region into a plurality of smaller regions and assigning each smaller region to a separate processing unit, when the progress data indicates that progress of encoding the particular region is insufficient.

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 processing for a first pixel in a picture comprises setting upper and/or lower limits of a first color component of the first pixel in a first color space to a respective fixed value if a maximum and/or minimum value of the first color component in the first color space results in a color component in a second color space that is below a first value of the color component in the second color space and above a second value of the color component in the second color space. A filtered value is obtained of the first color component and which is equal to or larger than the lower limit and equal to or lower than the upper limit. The processing results in filtered values that are cheaper to encode but that are visibly undistinguishable from the original colors of the pixels.

Abstract: A deblocking filtering control involves deciding whether to apply deblocking filtering to sample values in a sample block in a picture and in a neighboring sample block in the picture based on i) a first magnitude modification of sample prediction values in a first prediction block in a reference picture for the sample block and ii) a second magnitude modification of sample prediction values in a second prediction block in the reference picture for the neighboring sample block. The sample block and the neighboring sample block are separated in the picture by a block boundary. This decision to apply deblocking filtering based on magnitude modifications reduce blocking artefacts that may otherwise arise in certain pictures of a video sequence.

Abstract: A pixel pre-processing comprises subsampling a linear color in a first color space to obtain a subsampled linear color in the first color space. A first transfer function is applied to the subsampled linear color the first color space to obtain a subsampled non-linear color in the first color space. A first color transform is applied to the subsampled non-linear color in the first color space to obtain a subsampled first non-linear chroma component value and/or a subsampled second non-linear chroma component value in a second color space. A non-linear luma component value in the second color space is derived for the pixel, which together with the subsampled non-linear chroma component values represent a color the pixel. The pre-processing reduces chroma artifacts that may otherwise occur when chroma subsampling is performed following application of the first transfer function and the first color transform.

Abstract: An example method includes receiving a video bitstream with a high fidelity input format and side information related to the video bitstream. The side information includes a video bitstream representing the original video source with a low fidelity input 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. The method further includes decoding the side information to generate transcoding guiding information, estimating a representation of video bitstream with a low fidelity output format, based on the received bit stream and the generated transcoding guiding information, improving the estimated low-fidelity representation by adding the transform coefficients of the side information to transform coefficients generated from the estimated low-fidelity representation, and encoding the improved estimated representation of the low-fidelity bitstream.

Abstract: A method is disclosed performed in an encoder for encoding video pictures into a video bit stream, the method comprising: obtaining a denoised version of a reference picture; performing a matching procedure at least once, the matching procedure comprising matching a reference matching area of the reference picture to a matching area of a second picture and matching a reference matching area of the denoised version to the matching area of the second picture, and encoding a block of a current picture by selecting, for the block, a first prediction area based on a first reference area of the reference picture or a second prediction area based on a second reference area of the denoised version, wherein the prediction area having lowest matching error to the corresponding matching area of the second picture is selected. A corresponding method in a decoder is disclosed, and encoder, decoder, computer programs and computer program products.