公开(公告)号：US11477462B2

公开(公告)日：2022-10-18

申请号：US17121820

申请日：2020-12-15

Applicant: GOOGLE LLC

Inventor： Joseph Young ,  Dake He

IPC: H04N19/176 ,  H04N19/91 ,  H04N19/129 ,  H04N19/13 ,  H04N19/18 ,  H04N19/122 ,  H04N19/184 ,  H04N19/60 ,  H04N19/93 ,  H04N19/147 ,  H04N19/124 ,  H04N19/159 ,  H04N19/44

Abstract: An apparatus for decoding a current block includes a processor that is configured to obtain a transform class of a transform type used for decoding a transform block of the current block; select, based on the transform class, a template for coding a value related to a transform coefficient at a row and a column of the transform block; obtain, using the template, an index of a probability distribution in a table of probability distributions; and decode, from a compressed bitstream, the value using the probability distribution.

公开(公告)号：US11178409B2

公开(公告)日：2021-11-16

申请号：US16812539

申请日：2020-03-09

Applicant: GOOGLE LLC

Inventor： Joseph Young ,  Dake He

IPC: H04N19/176 ,  H04N19/13 ,  H04N19/18 ,  H04N19/129 ,  H04N19/91 ,  H04N19/93 ,  H04N19/147 ,  H04N19/184 ,  H04N19/124 ,  H04N19/159 ,  H04N19/44 ,  H04N19/122

Abstract: A method for coding a frame of a video stream includes selecting a first initial probability distribution for coding at least a first portion of the frame; updating, to obtain an updated first initial probability distribution and using backward adaptivity, the first initial probability distribution while coding the first portion of the frame; mapping the updated first initial probability distribution to a second initial probability distribution; and coding a second portion of the frame using the second initial probability distribution as an initial probability distribution. The first values of the first initial probability distribution are described using M bits, wherein M is a first positive integer. Second values of the updated first initial probability distribution are described using N bits, where N is a second positive integer that is greater than M. Third values of the second initial probability distribution are described using M bits.

公开(公告)号：US20200053367A1

公开(公告)日：2020-02-13

申请号：US16659666

申请日：2019-10-22

Applicant: GOOGLE LLC

Inventor： Joseph Young ,  Dake He

IPC: H04N19/18 ,  H04N19/44 ,  H04N19/159 ,  H04N19/124 ,  H04N19/129 ,  H04N19/13 ,  H04N19/176 ,  H04N19/184 ,  H04N19/147 ,  H04N19/93 ,  H04N19/91

Abstract: An apparatus includes a memory and a processor. The processor is configured to execute instructions stored in the memory to obtain a transform type for decoding a transform block for the current block; select, based on the transform type, a template for coding a value of a non-zero map; select, based on the template, a context for entropy decoding the value of the non-zero map; and decode the value of the non-zero map based on the context. The non-zero map indicates which coefficients of the transform block have non-zero values. A method includes obtaining a transform class for coding a transform block for the current block, wherein the transform class corresponding to a transform type and a direction; selecting, based on the transform class, a coding context for coding a value of a non-zero map; and coding the value of the non-zero map based on the coding context.

公开(公告)号：US20200021820A1

公开(公告)日：2020-01-16

申请号：US16580226

申请日：2019-09-24

Applicant: GOOGLE LLC

Inventor： Joseph Young ,  Dake He

IPC: H04N19/18 ,  H04N19/44 ,  H04N19/159 ,  H04N19/124 ,  H04N19/129 ,  H04N19/13 ,  H04N19/176 ,  H04N19/91

Abstract: A method for coding a current block using an intra-prediction mode includes defining a mapping from available intra-prediction modes to intra-prediction classes; determining, using the mapping, a first intra-prediction class of a first intra-prediction mode used for decoding a first neighboring block of the current block; determining, using the mapping, a second intra-prediction class of a second intra-prediction mode used for decoding a second neighboring block of the current block; using the first intra-prediction class and the second intra-prediction class as indices into a list of available context models to select a context model for coding the intra-prediction mode; and coding the intra-prediction mode using the context model. A first number of the intra-prediction classes is smaller than a second number of the available intra-prediction modes. each class is an ordinal value, and each available intra-prediction mode uniquely maps to one class of the intra-prediction classes.

公开(公告)号：US10992939B2

公开(公告)日：2021-04-27

申请号：US15790516

申请日：2017-10-23

Applicant: GOOGLE LLC

Inventor： Joseph Young

IPC: H04N19/159 ,  H04N19/117 ,  H04N19/176

Abstract: Coding a current block using a directional intra-prediction mode is described. A filter to apply to reference pixels peripheral to the current block is determined using a prediction angle of the intra-prediction mode and a size of the current block. The reference pixels are filtered using the filter to generate modified reference pixels, and a prediction block is generated for the current block using the intra-prediction mode and the modified reference pixels.

公开(公告)号：US20190174143A1

公开(公告)日：2019-06-06

申请号：US16267552

申请日：2019-02-05

Applicant: GOOGLE LLC

Inventor： Joseph Young

IPC: H04N19/593 ,  H04N19/117 ,  H04N19/182 ,  H04N19/159

Abstract: Coding a current block using a directional intra prediction mode is disclosed. The intra prediction mode includes a prediction angle and uses pixels peripheral to the current block to generate a prediction block. An apparatus determines, using the prediction angle, a filter to apply to the pixels peripheral to the current block; filters, using the filter, at least some of the pixels peripheral to the current block resulting in modified pixels; and generates a prediction block for the current block using the intra prediction mode and the modified pixels.

公开(公告)号：US20190124339A1

公开(公告)日：2019-04-25

申请号：US15790516

申请日：2017-10-23

Applicant: GOOGLE LLC

Inventor： Joseph Young

IPC: H04N19/159 ,  H04N19/176 ,  H04N19/117

Abstract: Coding a current block using a directional intra-prediction mode is described. A filter to apply to reference pixels peripheral to the current block is determined using the a prediction angle of the intra-prediction mode and a size of the current block. The reference pixels are filtered using the filter to generate modified reference pixels, and a prediction block is generated for the current block using the intra-prediction mode and the modified reference pixels.

公开(公告)号：US10893280B2

公开(公告)日：2021-01-12

申请号：US16659666

申请日：2019-10-22

Applicant: GOOGLE LLC

Inventor： Joseph Young ,  Dake He

IPC: H04N19/176 ,  H04N19/124 ,  H04N19/105 ,  H04N19/13 ,  H04N19/18 ,  H04N19/129 ,  H04N19/91 ,  H04N19/93 ,  H04N19/147 ,  H04N19/184 ,  H04N19/159 ,  H04N19/44 ,  H04N19/122

Abstract: An apparatus includes a memory and a processor. The processor is configured to execute instructions stored in the memory to obtain a transform type for decoding a transform block for the current block; select, based on the transform type, a template for coding a value of a non-zero map; select, based on the template, a context for entropy decoding the value of the non-zero map; and decode the value of the non-zero map based on the context. The non-zero map indicates which coefficients of the transform block have non-zero values. A method includes obtaining a transform class for coding a transform block for the current block, wherein the transform class corresponding to a transform type and a direction; selecting, based on the transform class, a coding context for coding a value of a non-zero map; and coding the value of the non-zero map based on the coding context.

公开(公告)号：US10440369B2

公开(公告)日：2019-10-08

申请号：US15819651

申请日：2017-11-21

Applicant: GOOGLE LLC

Inventor： Joseph Young ,  Dake He

IPC: H04N19/102 ,  H04N19/11 ,  H04N19/12 ,  H04N19/13 ,  H04N19/18 ,  H04N19/176 ,  H04N19/129 ,  H04N19/124 ,  H04N19/159 ,  H04N19/44 ,  H04N19/91 ,  H04N19/122

Abstract: A method for intra-coding a current block using an intra-prediction mode includes determining a left intra-mode of a left neighbor block and determining an above intra-mode of an above neighbor block. The method also includes, on condition that the left intra-mode and the above intra-mode are a same mode, using that same mode to determine a probability distribution for coding the intra-prediction mode and, on condition that at least one of the left intra-mode or the above intra-mode is a smooth intra-prediction mode, using the other of the left intra-mode and the above intra-mode to determine the probability distribution for coding the intra-prediction mode. The method also includes coding the intra-prediction mode using the probability distribution.

公开(公告)号：US20190124342A1

公开(公告)日：2019-04-25

申请号：US15798495

申请日：2017-10-31

Applicant: GOOGLE LLC

Inventor： Joseph Young ,  Dake He

IPC: H04N19/18 ,  H04N19/129 ,  H04N19/13 ,  H04N19/176

Abstract: Coding using level maps is disclosed. A method includes coding a scan position, in a forward scan direction, corresponding to an end-of-block and coding, in a backward scan direction, a non-zero map indicating positions of the transform block containing non-zero transform coefficients. The method also includes coding, in the backward scan direction, lower-range level maps, each lower-range level map having a respective map level up to a maximum map level, the lower-range level map indicating which absolute values of the non-zero transform coefficients are equal to the respective map level and which absolute values of the non-zero transform coefficients are greater than the respective map level. The method also includes coding a coefficient residual map, each residual coefficient of the coefficient residual map corresponding to a respective non-zero transform coefficient of the transform block having an absolute value exceeding the maximum map level.