公开(公告)号：US20190238879A1

公开(公告)日：2019-08-01

申请号：US16379062

申请日：2019-04-09

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  Yaowu Xu ,  James Bankoski ,  Jia Feng

IPC: H04N19/51 ,  H04N19/176 ,  H04N19/196 ,  H04N19/182

CPC classification number: H04N19/51 ,  H04N19/176 ,  H04N19/182 ,  H04N19/196 ,  H04N19/433 ,  H04N19/513 ,  H04N19/55

Abstract: A method for decoding an encoded block of an encoded frame includes selecting motion vectors corresponding to blocks of an extended collocated processing unit in a first reference frame; identifying a block of the blocks, such that the encoded block is a projection, using a motion vector of the block that refers to a third reference frame, onto the encoded frame; on condition that a block is identified, determining a temporal motion vector candidate for the encoded block in a second reference frame using a motion vector of the identified block and respective display orders of the encoded frame, the first reference frame, the second reference frame, and the third reference frame, and adding the temporal motion vector candidate to a motion vector candidate list; selecting a motion vector from the motion vector candidate list; generating a prediction block using the selected motion vector for decoding the encoded block.

公开(公告)号：US20190238865A1

公开(公告)日：2019-08-01

申请号：US15883323

申请日：2018-01-30

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  James Zern ,  Linfeng Zhang ,  Ching-Han Chiang ,  Yaowu Xu

IPC: H04N19/18 ,  H04N19/52 ,  H04N19/61 ,  H04N19/124 ,  H04N19/91 ,  H04N19/82 ,  H04N19/129

CPC classification number: H04N19/18 ,  H04N19/124 ,  H04N19/129 ,  H04N19/13 ,  H04N19/423 ,  H04N19/52 ,  H04N19/61 ,  H04N19/70 ,  H04N19/82 ,  H04N19/91

Abstract: Coding a transform block using level maps is disclosed. A method includes determining a lower plane of values, processing the lower plane in a backward scan order, and selecting a template for entropy-coding the values of the lower plane. The method also includes, for a current value of the lower plane, selecting, based on the template anti-diagonal lines, two or more line buffers, each of the two or more line buffers corresponding to a respective scan-order anti-diagonal line, determining a context using the two or more line buffers, and entropy encoding the current value using the context. Each value is a respective “up-to” value of a transform coefficient. The backward scan order visits the values of the lower plane along scan-order anti-diagonal lines. The template indicates scan positions of coded values of the lower plane, the scan positions are arranged, in the template, along template anti-diagonal lines.

公开(公告)号：US20190058897A1

公开(公告)日：2019-02-21

申请号：US15677220

申请日：2017-08-15

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  James Bankoski ,  Yaowu Xu

IPC: H04N19/573 ,  H04N19/567 ,  H04N19/70

Abstract: Dynamic motion vector referencing is used to predict motion within video blocks. A motion trajectory is determined for a current frame including a video block to encode or decode based on a reference motion vector used for encoding or decoding one or more reference frames of the current frame. One or more temporal motion vector candidates are then determined for predicting motion within the video block based on the motion trajectory. A motion vector is selected from a motion vector candidate list including the one or more temporal motion vector candidates and used to generate a prediction block. The prediction block is then used to encode or decode the video block. The motion trajectory is based on an order of video frames indicated by frame offset values encoded to a bitstream. The motion vector candidate list may include one or more spatial motion vector candidates.

公开(公告)号：US20190058883A1

公开(公告)日：2019-02-21

申请号：US15950225

申请日：2018-04-11

Applicant: GOOGLE LLC

Inventor： Ching-Han Chiang ,  Yaowu Xu ,  Jingning Han ,  Jia Feng

IPC: H04N19/129 ,  H04N19/159 ,  H04N19/61 ,  H04N19/124 ,  H04N19/13 ,  H04N19/82 ,  H04N19/86

Abstract: A method for coding a transform block of coefficients includes generating a new scan order from the original scan order such that a maximum scan distance of the new scan order is smaller than or equal to a predetermined distance, and coding the coefficients based on the new scan order. An apparatus for decoding a transform block of coefficients. The apparatus includes a memory and a processor. The memory includes instructions executable by the processor to identify an original scan order for encoding the coefficients, generate a new scan order from the original scan order such that a maximum scan distance of the new scan order is less than or equal to a predetermined distance, and decode, from an encoded bitstream, the coefficients based on the new scan order.

公开(公告)号：US20190020878A1

公开(公告)日：2019-01-17

申请号：US15646370

申请日：2017-07-11

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Jingning Han

IPC: H04N19/137 ,  H04N19/103 ,  H04N19/44 ,  H04N19/593 ,  H04N19/13

Abstract: Methods and apparatuses for coding a current block are disclosed. An apparatus for decoding a current block of size 8×8 including a memory and a processor is also disclosed. The processor configured to execute instructions stored in the memory to generate, for the current block, a luma block and a chroma block, divide the luma block into luma sub-blocks, and determine a respective prediction mode for each luma sub-block. The chroma block is of size 4×4, each luma sub-block is of size 4×4, and the respective prediction mode is an intra-mode or an inter-mode. The instructions also include instructions to, on condition that each of the respective prediction modes is the inter-mode, divide the chroma block into 2×2 chroma sub-blocks and determine a respective motion vector for each chroma sub-block.

公开(公告)号：US09967559B1

公开(公告)日：2018-05-08

申请号：US13764020

申请日：2013-02-11

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  Debargha Mukherjee

IPC: H04N19/61

CPC classification number: H04N19/176 ,  H04N19/00 ,  H04N19/00793 ,  H04N19/119 ,  H04N19/122 ,  H04N19/147

Abstract: Coding efficiency may be improved by subdividing a block into smaller sub-blocks for prediction. A first rate distortion value of a block optionally partitioned into smaller prediction sub-blocks of a first size is calculated using respective inter prediction modes and transforms of the first size. The residuals are used to encode the block using a transform of a second size smaller than the first size, generating a second rate distortion value. The values are compared to determine whether coding efficiency gains may result from inter predicting the smaller, second size sub-blocks. If so, the block is encoded by generating prediction residuals for the second size sub-blocks, and neighboring sub-blocks are grouped, where possible, based on common motion information. Each resulting composite residual block is transformed by a transform of the same size to generate another rate distortion value. The encoded block with the value is selected for the bitstream.