公开(公告)号：US20240276015A1

公开(公告)日：2024-08-15

申请号：US18641482

申请日：2024-04-22

Applicant: GOOGLE LLC

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

IPC: H04N19/60 ,  H04N19/129 ,  H04N19/13 ,  H04N19/184 ,  H04N19/88

CPC classification number: H04N19/60 ,  H04N19/129 ,  H04N19/13 ,  H04N19/184 ,  H04N19/88

Abstract: An encoded bitstream is decodable by a processor configured to execute instructions to store, in a first line buffer, first values of a first scan-order diagonal line scanned immediately before a current scan-order diagonal line of a transform block; and store, in a second line buffer, second values of a second scan-order diagonal line scanned immediately before the first scan-order diagonal line. The first values of the first line buffer and the second values of the second line buffer are interleaved in a destination buffer. Using the destination buffer, a probability distribution is selected for coding a current value of the current scan-order diagonal line. The current value is entropy decoded from the bitstream using the probability distribution. One of the second line buffer or the first line buffer is replaced with current values of the current scan-order diagonal line for coding values of an immediately subsequent scan-order diagonal line.

公开(公告)号：US12047606B2

公开(公告)日：2024-07-23

申请号：US17866612

申请日：2022-07-18

Applicant: Google LLC

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

IPC: H04N11/02 ,  G06N7/01 ,  G06N20/10 ,  H04N19/12 ,  H04N19/137 ,  H04N19/176 ,  H04N19/463 ,  H04N19/60 ,  H04N11/04 ,  H04N19/127 ,  H04N19/157

CPC classification number: H04N19/60 ,  G06N7/01 ,  G06N20/10 ,  H04N19/12 ,  H04N19/137 ,  H04N19/176 ,  H04N19/463 ,  H04N11/044 ,  H04N19/127 ,  H04N19/157

Abstract: Transform kernel candidates including a vertical transform type associated with a vertical motion and a horizontal transform type associated with a horizontal motion can be encoded or decoded. During a decoding operation, a probability model for decoding encoded bitstream video data associated with a transform kernel candidate for an encoded transform block is identified based on one or both of a first transform kernel candidate selected for an above neighbor transform block of the encoded transform block or a second transform kernel candidate selected for a left neighbor transform block of the encoded transform block. The encoded bitstream video data associated with the transform kernel candidate is decoded using the probability model.

公开(公告)号：US11218737B2

公开(公告)日：2022-01-04

申请号：US16042261

申请日：2018-07-23

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  Aki Kuusela ,  Stanislav Vitvitskyy ,  Yaowu Xu ,  Ching-Han Chiang ,  Dake He

IPC: H04N19/91 ,  H04N19/44 ,  H04N19/61 ,  H04N19/70

Abstract: Asymmetric probability model updating and entropy coding includes using different numbers of bits for storing probabilities of a probability model and for entropy coding symbols using that probability model. The probabilities of a probability model are updated according to values of syntax elements decoded from a bitstream. The probabilities are associated with possible values of the syntax elements and are stored using a first bit precision. Based on the updated probabilities, a second bit precision to use to entropy decode the syntax elements is determined. The second bit precision is less than the first bit precision. The syntax elements are then entropy decoded using the second bit precision, such as to produce quantized transform coefficients, which may be further processed and output to an output video stream. Using the first bit precision to entropy decode the syntax elements results in a lower compression throughput than using the second bit precision.

公开(公告)号：US11102477B2

公开(公告)日：2021-08-24

申请号：US16838544

申请日：2020-04-02

Applicant: GOOGLE LLC

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

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

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：US20200099956A1

公开(公告)日：2020-03-26

申请号：US16693438

申请日：2019-11-25

Applicant: GOOGLE LLC

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

IPC: H04N19/60 ,  H04N19/129 ,  H04N19/13 ,  H04N19/184 ,  H04N19/88

Abstract: A memory of an apparatus includes instructions executable by a processor to select a backward scan order for traversing, along scan-order anti-diagonal lines, a block of values related to the transform coefficients; select a template for entropy-coding the values, the template indicating, for a to-be-coded value, scan positions of already coded values, the scan positions arranged in at least two template anti-diagonal lines; maintain, for coding first values, where the first values are arranged along a current scan-order anti-diagonal line, a first line buffer and a second line buffer; for a current value of the current scan-order anti-diagonal line, determine a context using the first line buffer and the second line buffer, and entropy encode, in a compressed bitstream, the current value using the context; and replace one of the second line buffer or the first line buffer with the current scan-order anti-diagonal line.

公开(公告)号：US20200029098A1

公开(公告)日：2020-01-23

申请号：US16042261

申请日：2018-07-23

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  Aki Kuusela ,  Stanislav Vitvitskyy ,  Yaowu Xu ,  Ching-Han Chiang ,  Dake He

IPC: H04N19/91 ,  H04N19/70 ,  H04N19/61 ,  H04N19/44

Abstract: Asymmetric probability model updating and entropy coding includes using different numbers of bits for storing probabilities of a probability model and for entropy coding symbols using that probability model. The probabilities of a probability model are updated according to values of syntax elements decoded from a bitstream. The probabilities are associated with possible values of the syntax elements and are stored using a first bit precision. Based on the updated probabilities, a second bit precision to use to entropy decode the syntax elements is determined. The second bit precision is less than the first bit precision. The syntax elements are then entropy decoded using the second bit precision, such as to produce quantized transform coefficients, which may be further processed and output to an output video stream. Using the first bit precision to entropy decode the syntax elements results in a lower compression throughput than using the second bit precision.

公开(公告)号：US10455253B1

公开(公告)日：2019-10-22

申请号：US15445063

申请日：2017-02-28

Applicant: GOOGLE LLC

Inventor： Stanislav Vitvitskyy ,  Jingning Han ,  Ching-Han Chiang ,  Adrian W. Grange

IPC: H04N7/00 ,  H04N19/52 ,  H04N19/117 ,  H04N19/80 ,  H04N19/51

Abstract: A first interpolation filter is selected for a first direction of the prediction block, and a second interpolation filter is selected for a second direction of the prediction block. The first interpolation filter has a first number of taps and the second interpolation filter has a second number of taps. The second interpolation filter is set to an interpolation filter having a third number of taps in response to determining that the first number of taps is greater than a threshold number of taps and the second number of taps is greater than a threshold number of taps. The third number of taps is smaller than or equal to the threshold number of taps. The prediction block is generated using the first interpolation filter and the second interpolation filter.

公开(公告)号：US20190313123A1

公开(公告)日：2019-10-10

申请号：US16451415

申请日：2019-06-25

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  Ching-Han Chiang

IPC: H04N19/60 ,  H04N19/192 ,  H04N19/136 ,  H04N19/129 ,  H04N19/176 ,  H04N19/91 ,  H04N19/18 ,  H04N19/134

Abstract: Video coding using a context adaptive scan order for entropy coding may include an apparatus decoding a current block by identifying a context adaptive scan order for entropy decoding a transform block, which may include identifying non-zero-coefficient probabilities for the transform block such that each location in the transform block corresponds to a respective non-zero-coefficient probability from the non-zero-coefficient probabilities, assigning a respective context adaptive scan order position to each location in the transform block in descending magnitude order of the respective corresponding non-zero-coefficient probabilities such that the context adaptive scan order position for each location exceeds the context adaptive scan order position assigned to entropy coding context locations for the respective location, entropy decoding transform coefficients from the encoded video stream based on the context adaptive scan order, and reconstructing the decoded block based on the transform 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：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.