Abstract: In one aspect there is disclosed a method of applying deblocking on implicit vertical TU boundaries when the CU width is larger than the maximum TU width and applying deblocking on implicit horizontal TU boundaries when the CU height is larger than the maximum TU height. Some exemplary embodiments include HEVC deblocking and deblocking using longer filters.

Abstract: A decoder (100) receives (30) a set of N compressed segments of a first picture, and a set of M compressed segments for a second picture that follows the first picture in a decoding order. Based on the set of N compressed segments, the decoder constructs a decodable picture for the first picture and decodes (32) the decodable picture. Based on the set of M compressed segments, the decoder constructs a decodable second picture in the compressed domain, in which each of the segments of the first picture are placed at the same spatial position as that of a corresponding segment in the second picture, and decodes (52) the decodable second picture. Additionally, at least one Intra coded segment is placed at one of the M spatial positions in the compressed domain in which there is no segment of the N segments.

Abstract: A method performed by a device for filtering a current block adjacent to an upper block and a left block is provided. The method includes (1) filtering a first sample located in a top-left area of the current block using (i) at least one sample from the upper block above the top-left area, (ii) at least one sample from the left block, and (iii) at least one unfiltered sample value for the first sample; (2) filtering a second sample located in a top-right area of the current block using (i) at least one sample from the upper block and (ii) at least one unfiltered sample value for the second sample; and (3) filtering a third sample located in a bottom-left area of the current block using (i) at least one sample from the left block and (ii) at least one unfiltered sample value for the third sample.

Abstract: A method of processing a video sequence including images, wherein each image includes blocks of sample values, is provided. The method includes determining input and output lengths for deblocking filtering of sample values for a first and second side of a potential blocking boundary. The input and output lengths are consecutive sample values, from a sample value closest to the potential blocking boundary to one or more other sample values spaced from the potential blocking boundary. The input and output lengths are determined based on a number of consecutive sample values from the sample value closest to the potential blocking boundary to another sample value closest to a neighboring potential blocking boundary. The method includes deblocking filtering of the sample values on the at least one of the first and second side of the potential blocking boundary, using the input and output lengths, to generate deblocked sample values.

Abstract: In encoding a picture, comprising a plurality of tiles, into a bit-stream, a method and apparatus is provided for signaling the tile attribute values per-tile, using a compact syntax. These embodiments signal per-tile attribute values using a loop over the tiles. The tile attributes may, for example, be in the form of a set of tile syntax elements (one syntax element per tile attribute), or for example in the form of a set of flags to enable or disable the usage of the tile attributes. These embodiments provide freedom for an encoder to assign the tile attribute values per tile, or per any subset of tiles in a picture, and the attribute values are signaled in a compact syntax using a loop (or loops) over tiles.

Abstract: A method of processing a video sequence including images, wherein each image includes blocks of sample values, is provided. The method includes determining input and output lengths for deblocking filtering of the sample values for a first and second side of a potential blocking boundary. The input and output lengths are a number of consecutive sample values, from a sample value closest to the potential blocking boundary to one or more other sample values spaced from the potential blocking boundary. The input and output lengths are determined based on a number of consecutive smooth sample values perpendicular to the potential blocking boundary on respectively the first and/or second side of the potential blocking boundary. The method includes deblocking filtering of the sample values on the at least one of the first and second side of the potential blocking boundary, using the input and output lengths, to generate deblocked sample values.

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 method (400) performed by a decoder (260, 600, 701) for decoding a bitstream comprising a picture parameter set, PPS, and a first set of slices. The method includes obtaining (s402) the picture parameter set. The method also includes decoding (s404) a syntax element included in the picture parameter set to obtain an indicator value. The decoder is configured such that if the indicator value is set to a first value then the decoder determines that a picture header included in the bitstream comprises a parameter value corresponding to a particular parameter, otherwise the decoder determines that each slice included in the first set of slices comprises a parameter value corresponding to the particular parameter. If the picture header comprises the parameter value corresponding to the particular parameter, then this parameter value is used to decode slice data of each slice included in the first set of slices.

Abstract: There are provided mechanisms for signaling region information in a bitstream for region-wise unpacking of regions from a packed picture to a projected picture. The method comprises defining a scale factor that is common for all regions of a picture. The method comprises signaling the scale factor in the bitstream. The method further comprises, for each of at least one region of a picture, applying the scale factor to each item of the region information for the region to produce a set of scaled values. The method comprises signaling the scaled values in the bitstream. Mechanisms for parsing region information from a bitstream for region-wise unpacking of regions from a packed picture to a projected picture are also provided.

Abstract: An encoder (400), a decoder (450), and methods (20, 30) for partitioning a picture from a sequence of video pictures into a layout having a plurality of flexible tiles or segments is disclosed. Each tile or segment (T) comprises a single rectangular or square region. The encoder generates (22) a partition structure and encodes (28) the tiles according to the partition structure. The encoder also generates a bitstream (12) comprising a plurality of coded segments and information indicating the partition structure used to partition the picture into the plurality of flexible tiles or segments, and sends (29) the bitstream to the decoder. Upon receipt the decoder uses the coded segments and information in the bitstream to decode (38) the plurality of coded segments.

Abstract: A deblocking the method. The method includes deblocking a block boundary between a first block, B1, and a second block, B2, with the restriction that not more than 5 samples are modified on the B2 side of the block boundary as a result of the deblocking. The deblocking method also includes deblocking a sub-block boundary within the B2 block such that not more than 2 samples on the side of the sub-block boundary within the B2 block that is closest to the block boundary between B1 and B2 are modified by the deblocking.

Abstract: An encoder calculates an indication to a previous reference picture having temporal identity of zero. The encoder creates a first set of indicators to the previous reference picture, to all reference pictures in a first reference picture set of the previous reference picture, and to all pictures following the previous reference picture in decoding order and precede the current picture in decoding order. The encoder sets a flag for picture order count cycle, when a long term reference picture (LTRP) has least significant bits (LSBs) of a picture order count, for which more than one picture in the first set share same value of the LSBs of picture order count as the LTRP. The decoder obtains LSB of a picture order count for a LTRP in a reference picture set of the current picture. The decoder concludes non-compliant bitstream based on indications provided by the flag.

Abstract: A method of decoding a block of video samples from a video bitstream is provided in which the method includes decoding a DQPRP value, deriving a PQP value for a block having a non-zero residual, decoding a DDQP value for the block, deriving a SDQP value for the block from the DDQP value and the DQPRP value, deriving a block QP value for the block from the SDQP value and the PQP value, decoding at least one non-zero coefficient of the block, deriving values of a residual block for the block by first scaling the at least one non-zero coefficient using the QP value and thereafter applying an inverse transform, deriving values of a prediction block spatial or temporal prediction, and deriving decoded sample values for the block by adding the values of the residual block and the values of the prediction block.

Abstract: A method for decoding a picture from a bitstream. In one embodiment, The method includes: receiving a slice header for a slice of the picture, wherein the slice header comprises a state syntax element; decoding a state value from the state syntax element in the slice header, wherein a) if the state value is not equal to a first value, then the state value indicates that i) the bitstream includes for the picture a picture header comprising a set of picture syntax elements and ii) the slice header does not comprise the set of picture syntax elements and b) if the state value is equal to the first value, then the state value indicates that i) the slice header contains said set of picture syntax elements and ii) the bitstream does not include a picture header for the picture; and using the set of picture syntax elements to decode the slice of the picture.

Abstract: A length indicator associated with an encoded representation of a slice is parsed. The length indicator is indicative of a length of an extension field present in a slice header of the encoded representation. A decoder can then determine to ignore, during decoding of the encoded representation, any value of the extension field in the slice header where these values are identified based on the length indicator. As a consequence, an extension field can be added to slice headers and still enable legacy decoders to correctly decode the encoded representations.

Abstract: A picture with multiple slices is encoded by generating a coded slice representation for each of the slices. A slice flag is set to a first value for the first slice in the picture and corresponding slice flags of the remaining slices are set to a second defined value. A respective slice address is generated for each remaining slice to enable identification of the slice start position within the picture for the slice. A coded picture representation of the picture comprises the coded slice representations, the slice addresses and the slice flags. The slice flags enable differentiation between slices for which slice addresses are required and the slice per picture for which no slice address is needed to identify its slice start position.

Abstract: A mode signaling syntax element is provided based on an encoded representation of a picture in a video sequence. The mode signaling syntax element is employed to determine whether a final reference picture list is the same for all slices of a same slice type in the picture. The mode signaling syntax element signals to a decoder that it does not necessarily have to repeat computationally complex reference picture list construction functions for each slice in the picture.

Abstract: Method for decoding a picture, comprising: decoding information that the picture is partitioned into more than one segment based on one or more syntax elements in a bitstream; decoding information that the spatial segmentation is uniform based on the one or more syntax elements; determining a segment unit size based on the one or more syntax elements or based on a predefined segment unit size; decoding a first value indicating a segment width from one or more code words in the bitstream; decoding a second value indicating a segment height from the one or more code words; deriving segment column widths based on a picture width in number of segment units and the first value; deriving segment row heights based on a picture height in number of segment units and the second value; deriving a spatial location for a current block based on the derived segment column widths and the derived segment heights; and decoding the current block based on the derived spatial location.

Abstract: A method of decoding a block of video samples from a video bitstream is provided in which the method includes decoding a DQPRP value, deriving a PQP value for a block having a non-zero residual, decoding a DDQP value for the block, deriving a SDQP value for the block from the DDQP value and the DQPRP value, deriving a block QP value for the block from the SDQP value and the PQP value, decoding at least one non-zero coefficient of the block, deriving values of a residual block for the block by first scaling the at least one non-zero coefficient using the QP value and thereafter applying an inverse transform, deriving values of a prediction block spatial or temporal prediction, and deriving decoded sample values for the block by adding the values of the residual block and the values of the prediction block.

Abstract: The present embodiments introduce a new type of random access point in video bitstreams that can be used for random access operations but can be represented in encoded form at a lower bit-cost as compared to IRAP pictures. The random access point is a dependent random access point (DRAP) picture that is encoded and decoded using an IRAP picture as sole reference picture for the DRAP picture. The DRAP picture is encoded as a trailing picture that may be used for reference and constitutes a random access point in a video bitstream.