公开(公告)号：US10951894B2

公开(公告)日：2021-03-16

申请号：US16535154

申请日：2019-08-08

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  Dake He

IPC: H04N19/129 ,  H04N19/176 ,  H04N19/18 ,  H04N19/61 ,  H04N19/82

Abstract: A scan order for encoding or decoding coefficients of a transform block is selected on a transform block-level. A set of candidate scan orders is processed by identifying end of block positions within the transform block for each of the candidate scan orders. Cost values are determined for each of the candidate scan orders to reflect a number of the coefficients of the transform block that are located before the respective end of block positions. In particular, a cost value for a candidate scan order reflects the number of zero-value coefficients located before the end of block position for that candidate scan order. One of the candidate scan orders is then selected based on those cost values. The selected scan order is used to scan the coefficients in the transform block, such as for encoding those coefficients to a bitstream or for decoding those coefficients to an output video stream.

公开(公告)号：US10771803B2

公开(公告)日：2020-09-08

申请号：US16379062

申请日：2019-04-09

Applicant: GOOGLE LLC

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

IPC: H04N19/00 ,  H04N19/51 ,  H04N19/196 ,  H04N19/182 ,  H04N19/176 ,  H04N19/513 ,  H04N19/433 ,  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：US20200236350A1

公开(公告)日：2020-07-23

申请号：US16838544

申请日：2020-04-02

Applicant: GOOGLE LLC

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

IPC: H04N19/105 ,  H04N19/167 ,  H04N19/18 ,  H04N19/91 ,  H04N19/13

Abstract: A sign value of a DC coefficient of a current block is determined using neighbor blocks of the current block. First and second sign values are identified as respectively corresponding to an above neighbor block of the current block and a left neighbor block of the current block. A context value is calculated by applying a first weighting value to the first sign value and a second weighting value to the second sign value. The first weighting value is based on a boundary between the above neighbor block and the current block, and the second weighting value is based on a boundary between the left neighbor block and the current block. A probability value is selected based on the context value. The sign value of the DC coefficient of the current block is then determined using the probability model.

公开(公告)号：US10652535B1

公开(公告)日：2020-05-12

申请号：US16287881

申请日：2019-02-27

Applicant: GOOGLE LLC

Inventor： Cheng Chen ,  Jingning Han

IPC: H04N19/117 ,  H04N19/172 ,  H04N19/426

Abstract: A memory-efficient filtering approach is used to code images and video. A buffer having a fixed size based on a size of processing units to use for filtering a video frame is allocated. For each of the processing units, pre-filtered pixel values are copied from a respective region of the video frame to the buffer based on a writing point for the video frame and an offset applied to the writing point, filtering is performed against the pre-filtered pixel values from the buffer to produce filtered pixel values, and the filtered pixel values are written to the video frame based on the writing point and the offset. The filtering may be performed using a loop restoration tool, such as where the pre-filtered pixel values are output from a constrained directional enhancement filter (CDEF) tool. Alternatively, the filtering may be performed using the CDEF tool or another coding tool.

公开(公告)号：US10531124B1

公开(公告)日：2020-01-07

申请号：US16016980

申请日：2018-06-25

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  Yaowu Xu

IPC: H04N19/66 ,  H04N19/119 ,  H04N19/176 ,  H04N19/96 ,  H04N19/192 ,  H04N19/50

Abstract: Multi-stage coding block partition search is disclosed. A method includes selecting a partition-none partition type and a partition-split partition type for predicting the block, determining a first cost of predicting the block using the partition-none partition type, and determining a second cost of predicting the block using the partition-split partition type. The partition-none partition type and the partition-split partition type are selected from a set of partition types that includes the partition-none partition type, the partition-split partition type, and third partition types. The method also includes, on condition that the result meets a criterion, determining a respective encoding cost corresponding to at least some of the third partition types; selecting a selected partition type corresponding to a minimal cost amongst the partition-none partition type and the at least some of the third partition types; and encoding, in a compressed bitstream, the selected partition type.

公开(公告)号：US10484707B1

公开(公告)日：2019-11-19

申请号：US16511389

申请日：2019-07-15

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Jingning Han

IPC: H04N19/52 ,  G06T7/20 ,  G06T9/00 ,  H04N19/159 ,  H04N19/139 ,  H04N19/527 ,  H04N19/44 ,  H04N19/109 ,  H04N19/176

Abstract: Candidate motion vectors are identified from previously coded blocks. For each candidate, a distance between a previously coded block associated with the candidate and a current block and a popularity value based previously coded pixels associated with the candidate are determined. Each candidate is ranked within a list according to a priority value, the priority value based on the distance and the popularity value associated with the candidate. The ranking also includes determining reference blocks that share first and second reference frames for decoding the current block using compound prediction, and assigning a higher priority to candidates that share the same combination of the reference frames within the list than combinations of candidates encoded using respective single reference frames of the first reference frame and the second reference frame. The reference motion vector is selected from the list and is used to decode the current block.

公开(公告)号：US10412410B2

公开(公告)日：2019-09-10

申请号：US15675979

申请日：2017-08-14

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  Yaowu Xu

IPC: H04N5/225 ,  H04N19/573 ,  H04N19/52 ,  H04N19/107 ,  H04N19/172 ,  H04N19/176 ,  H04N19/91 ,  H04N19/82 ,  H04N19/86 ,  H04N19/61 ,  H04N19/70 ,  H04N19/126 ,  H04N19/567 ,  H04N19/577

Abstract: A prediction scheme is selected for encoding or decoding a video block. A first compound motion block can be determined by weighting distances from a first reference frame to the video frame and from a second reference frame to the video frame using one or more quantized weighting coefficients. A second compound motion block can be determined based on an average of pixel values a video block of the first reference frame and pixel values from a video block of the second reference frame. One of the first compound motion block or the second compound motion block is selected and used to generate a prediction block. Alternatively, data encoded to a bitstream including the video frame can be used to determine which compound motion block to use to generate the prediction block. The current block of the video frame is then encoded or decoded using the prediction block.

公开(公告)号：US20190215533A1

公开(公告)日：2019-07-11

申请号：US16299436

申请日：2019-03-12

Applicant: GOOGLE LLC

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

IPC: H04N19/60 ,  H04N19/645 ,  H04N19/70 ,  H04N19/129 ,  H04N19/18 ,  H04N19/88 ,  H04N19/44 ,  H04N5/232 ,  G08B13/196 ,  G06K9/00 ,  H04N19/157 ,  H04N19/91 ,  H04N19/13 ,  H04N19/48

Abstract: Encoding a transform block includes de-composing transform coefficients of the transform block into binary level maps arranged in a tier and a residual transform map, the binary level maps formed by breaking down a value of a respective transform coefficient into a series of binary decisions; and encoding, using a context model, a to-be-encoded binary decision that is at a scan location in a scan order, the to-be-encoded binary decision being a value of a binary level map at a level k. The context model is selected using first neighboring binary decisions of the binary level map at a level k that precede the to-be-encoded binary decision; and second neighboring binary decisions of a binary level map at a level (k−1), the second neighboring binary decisions including values that precede and values that follow, in the scan order, a co-located binary decision of the to-be-encoded binary decision.

公开(公告)号：US10142652B2

公开(公告)日：2018-11-27

申请号：US15147053

申请日：2016-05-05

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Jingning Han

IPC: H04N7/12 ,  H04N19/56 ,  H04N19/513 ,  H04N19/91 ,  H04N19/176 ,  H04N19/573 ,  H04N19/583

Abstract: Techniques are described to code motion vectors using reference motion vectors to reduce the amount of bits needed. One method includes determining, for a current block of the video bitstream, a reference motion vector from a varying number of candidate reference motion vectors, wherein the reference motion vector is associated with a reference block and includes a predicted portion and a residual portion; selecting a probability context model for the current block by evaluating the residual portion of the reference motion vector with one or more thresholds; and entropy decoding, for the current block using a processor, a motion vector residual associated with the current block using the probability context model.

公开(公告)号：US10116957B2

公开(公告)日：2018-10-30

申请号：US15266400

申请日：2016-09-15

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Jingning Han

IPC: H04N19/13 ,  H04N19/513 ,  H04N19/159 ,  H04N19/105 ,  H04N19/82 ,  H04N19/124 ,  H04N19/61 ,  H04N19/176 ,  H04N19/172 ,  H04N19/182

Abstract: Inter-prediction using a dual filter type is described. To decode a video frame, a block location within a reference frame is determined using a motion vector and a location of a current block to be decoded. Rows of pixel values of a temporal pixel block or columns of pixel values of the temporal pixel block are generated applying a first interpolation filter to pixels corresponding to the block location along a first axis. Columns of pixel values or rows of pixel values for a first prediction block are generated by applying a second interpolation filter to the pixel values of the temporal pixel block along a second axis perpendicular to the first axis. The first and second interpolation filters are different. An encoded residual block is decoded to generate a residual block, and combining the residual block with the first prediction block reconstructs the current block.