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: 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: 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: 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 processing of pixels comprises checking whether a color component of a pixel in a color space resulting in a smallest error between at least one color component in another color space determined based on the color component and at least one original color component of the pixel in the another color space causes any color channel of the pixel to fall outside of an allowed range. A value of the color component is obtained using a first function/LUT if the color component resulting in the smallest error does not cause any color channel of the pixel to fall outside of said allowed range. However, a value of the color component is obtained using a second, different function/LUT if the color component resulting in the smallest error causes any color channel of the pixel to fall outside of the allowed range.

Abstract: There are provided mechanisms for encoding a picture of a video sequence in a video bitstream. The picture comprises a first block of samples, wherein each sample in the first block of samples has sample values associated with at least a luma color component and a chroma color component. Each color component is assigned a first quantization parameter. The method comprises calculating a quantization parameter change for at least one color component in the first block of samples, with respect to the first quantization parameter, based on statistics calculated from the sample values from at least one color component in a second block of samples. The second block of samples is one of: source samples of the first block of samples and source samples larger than the first block of samples including the first block of samples.

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.