Patents by Inventor Chen-Yen LAI

Chen-Yen LAI has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20210321089
    Abstract: A method and apparatus of video coding using history-based candidate derivation are disclosed. According to one method, a current block is inside a Shared Merge candidate list Region (SMR) or a history-based parallel processing region is received. The current block is encoded or decoded using a Merge candidate list. Only if the current block is one of first-coded N (N?0) blocks, one of last-coded N blocks, or one of selected N blocks, the history-based candidate list is updated after the current block is encoded or decoded. In one embodiment, Merge candidate list is pre-generated for the current block in the SMR and is separately generated for the current block in the history-based parallel processing region. In another method, if the current block is inside the SMR or the history-based parallel processing region, the current block is encoded or decoded using a history-based candidate list associated with the root CU.
    Type: Application
    Filed: October 5, 2019
    Publication date: October 14, 2021
    Inventors: Yu-Cheng LIN, Chen-Yen LAI, Chun-Chia CHEN, Yu-Ling HSIAO, Tzu-Der CHUANG, Ching-Yeh CHEN, Chih-Wei HSU
  • Publication number: 20210321106
    Abstract: A method and apparatus for video coding are disclosed. According to the present invention, a flag is determined, where the flag indicates whether a scaling matrix is enabled or not enabled for non-separable secondary transform (NSST) coded blocks. When the current block is one NSST coded block and the flag indicates that the scaling matrix is enabled for the NSST blocks, the scaling matrix is determined and applied to the current block. When the current block is one NSST coded block and the flag indicates that the scaling matrix is not enabled for the NSST coded blocks, the scaling matrix is skipped for the current block. According to another method, for a rectangular block, a target scaling matrix is generated directly from a square base scaling matrix in one step without up-sampling-and-down-sampling or down-sampling-and-up-sampling.
    Type: Application
    Filed: June 17, 2021
    Publication date: October 14, 2021
    Applicant: MEDIATEK INC.
    Inventors: Chen-Yen LAI, Olena CHUBACH, Tzu-Der CHUANG, Ching-Yeh CHEN
  • Publication number: 20210314560
    Abstract: Video processing methods comprise receiving input data of a current block in a current picture, constructing a candidate list for the current block by including one or more History-based Motion Vector Predictor (HMVP) candidates, selecting one candidate from the candidate list, locating a reference block according to motion information of the selected candidate, and encoding or decoding the current block by predicting the current block using the reference block. The one or more HMVP candidates are fetched from a normal HMVP table if the current block is to be processed by a normal inter prediction mode, and the one or more HMVP candidates are fetched form a Current Picture Referencing (CPR) HMVP table if the current block is to be processed by a CPR mode. The two HMVP tables are separately maintained and updated.
    Type: Application
    Filed: November 6, 2019
    Publication date: October 7, 2021
    Inventors: Chen-Yen LAI, Yu-Ling HSIAO, Tzu-Der CHUANG, Ching-Yeh CHEN
  • Publication number: 20210306659
    Abstract: A method and apparatus of Inter prediction for video coding using UMVE (Ultimate Motion Vector Expression) are disclosed. According to this method, a base candidate is selected from an original Inter candidate list, where the base candidate has a base prediction direction. One or more extended candidates are derived by adding one or more offsets to the base candidate, where said one or more extended candidates have a same prediction direction as the base prediction direction. The extended candidates are then inserted into the original Inter candidate list to form an extended Inter candidate list for encoding or decoding. According to another method, the UMVE mode is treated as an additional AMVP (Advanced Motion Vector Prediction) mode.
    Type: Application
    Filed: July 31, 2019
    Publication date: September 30, 2021
    Inventors: Chen-Yen LAI, Ching-Yeh CHEN, Tzu-Der CHUANG
  • Patent number: 11109056
    Abstract: Methods and apparatus for a video coding system with the current picture referencing (CPR) mode enabled are disclosed. According to one method, when the current reference picture is equal to the current picture, an integer motion vector flag is inferred to be true without signalling the integer or parsing the motion vector flag. In another method, when all motion vector differences for the current block are equal to zero, an integer motion vector flag is inferred to be true without signalling the integer or parsing the motion vector flag. In yet another method, when all reference pictures for the current block are equal to the current picture: the sub-block prediction coding mode is disabled; and the current block is encoded or decoded by disabling the sub-block prediction coding mode. Alternatively, derived motion vectors associated with sub-blocks for the current block can be converted into integer motion vectors.
    Type: Grant
    Filed: February 11, 2019
    Date of Patent: August 31, 2021
    Assignee: MEDIATEK INC.
    Inventors: Chen-Yen Lai, Zhi-Yi Lin, Ching-Yeh Chen, Tzu-Der Chuang
  • Publication number: 20210258587
    Abstract: A video coding method using inter-layer prediction or referencing is provided. A video decoder receives data from a bitstream carrying data for video pictures in a plurality of different layers. At least one of the plurality of layers comprises temporal sublayers that correspond to levels in a hierarchical temporal prediction structure. Each temporal sublayer is associated with a temporal identifier. The video decoder receives an inter-layer prediction constraint parameter constraining a maximum temporal sublayer used in inter-layer prediction. The video decoder reconstructs a first picture in a first layer by referencing data of a second picture in a second layer. A temporal identifier of the referenced data satisfies the received inter-layer prediction constraint parameter.
    Type: Application
    Filed: February 19, 2021
    Publication date: August 19, 2021
    Inventors: Chen-Yen Lai, Ching-Yeh Chen, Tzu-Der Chuang, Olena Chubach
  • Publication number: 20210250604
    Abstract: Method and apparatus of using Bi-directional optical flow (BIO) for a true bi-direction predicted block are disclosed. According to one method of the present invention, the gradients are limited to a predefined bit-depth in order to reduce the computational complexity. According to another method, the data range of gradient sum and/or the difference between L0 and L1 interpolated pixels are shifted by a predefined bit-depth. The pre-defined bit-depth can be implicitly determined or signalled in a bit stream at a sequence level, picture level or slice level. The pre-defined bit-depth can also be determined dependent on input bit-depth.
    Type: Application
    Filed: June 10, 2019
    Publication date: August 12, 2021
    Inventors: Yu-Chi SU, Ching-Yeh CHEN, Tzu-Der CHUANG, Chen-Yen LAI
  • Patent number: 11070815
    Abstract: Method and apparatus of video coding are disclosed. According to the method, a boundary region in the current block is determined. For each pixel in the boundary region, an Intra predictor and an Inter predictor care derived. An Intra-Inter predictor is generated by blending the Intra predictor and the Inter predictor. Pixels in the boundary region of the current block are encoded or decoded using the Intra-Inter predictor. For the remaining pixels in the current block not belonging to the boundary region, the pixels are encoded or decoded using the Inter predictor or the Intra predictor. In another method, the Intra-Inter prediction process is implemented by scaling the sum of the Intra weighting factor and the Inter weighting factor is scaled to a power-of-2 number to avoid the need for the division operation. In yet another method, the Intra-Inter prediction is applied depending on the current block size.
    Type: Grant
    Filed: June 7, 2018
    Date of Patent: July 20, 2021
    Assignee: MEDIATEK INC.
    Inventors: Chen-Yen Lai, Ching-Yeh Chen, Chih-Wei Hsu, Yu-Wen Huang
  • Patent number: 11070825
    Abstract: Video processing methods include receiving input data of a current block in a current picture, determining if a luma component and chroma components of the current block are coded using different splitting trees, disabling Adaptive Colour Transform (ACT) on the current block when the luma component and the chroma components of the current block are coded using different splitting trees, and encoding or decoding the current block. ACT is only allowed to be performed on blocks coded in single tree block partitioning to convert a RGB colour space into an YCoCg colour space. ACT is applied to residues according to some embodiments, or ACT is applied to input data and predictors according to some other embodiments.
    Type: Grant
    Filed: June 10, 2020
    Date of Patent: July 20, 2021
    Assignee: MEDIATEK INC.
    Inventors: Chen-Yen Lai, Tzu-Der Chuang, Ching-Yeh Chen
  • Publication number: 20210218966
    Abstract: A video decoder parses a sequence parameter set (SPS) that is applicable to a current sequence of video pictures that includes the current picture, the SPS comprises a first dependent quantization flag and a first sign hiding flag. When the first dependent quantization flag indicates that dependent quantization is enabled for the current sequence, the decoder parses a second dependent quantization flag for indicating whether dependent quantization is used for quantizing the one or more slices of the current picture. When the second dependent quantization flag indicates that dependent quantization is not used for one or more slices of the current picture and the first sign hiding flag indicates that sign hiding is enabled for the current sequence, the decoder parses a second sign hiding flag for indicating whether sign hiding is used for quantizing the one or more slices of the current picture.
    Type: Application
    Filed: January 7, 2021
    Publication date: July 15, 2021
    Inventors: Chen-Yen Lai, Chih-Wei Hsu, Tzu-Der Chuang, Ching-Yeh Chen
  • Publication number: 20210176475
    Abstract: A method for specifying layout of subpictures in video pictures is provided. A video decoder receives data from a bitstream to be decoded as a current picture of a video. For a current subpicture of a set of subpictures of the current picture, the video decoder determines a position of the current subpicture based on a width and a height of the current picture and a previously determined width and height of a particular subpicture in the set of subpictures. The video decoder reconstructs the current picture and the current subpicture based on the determined position.
    Type: Application
    Filed: December 2, 2020
    Publication date: June 10, 2021
    Inventors: Chih-Wei Hsu, Lulin Chen, Yu-Ling Hsiao, Chun-Chia Chen, Ching-Yeh Chen, Chen-Yen Lai
  • Publication number: 20210176501
    Abstract: Encoding methods and apparatuses include applying a Cross-Component Adaptive Loop Filter (CCALF) processing on a current picture based on CCALF coefficients signaled in one or more Adaptive Loop Filter (ALF) Adaptation Parameter Sets (APSs) to refine one or more chroma components according to a luma component, signaling two ALF signal flags and two CCALF signal flags in each ALF APS or parsing two ALF signal flags and two CCALF signal flags from each ALF APS, and encoding or decoding the current picture. Values of the two ALF signal flags and the two CCALF signal flags in each ALF APS are not all equal to 0 to ensure none of the ALF APS is an empty APS.
    Type: Application
    Filed: December 3, 2020
    Publication date: June 10, 2021
    Inventors: Ching-Yeh CHEN, Olena CHUBACH, Chen-Yen LAI, Tzu-Der CHUANG, Chih-Wei HSU, Yu-Wen HUANG
  • Publication number: 20210160527
    Abstract: Video processing methods and apparatuses for coding a current block comprise receiving input data of a current block, partitioning the current block into multiple sub-blocks, deriving sub-block MVs for the current block according to a sub-block motion compensation coding tool, constraining the sub-block MVs to form constrained sub-block MVs, and encoding or decoding the current block using the constrained sub-block MVs. The sub-block MVs may be constrained according to a size, width, or height of the current block or a sub-block, an inter prediction direction of one of control point MVs of the current block, the current block, or current sub-block, the control point MVs, or a combination of the above.
    Type: Application
    Filed: April 2, 2019
    Publication date: May 27, 2021
    Inventors: Tzu-Der CHUANG, Ching-Yeh CHEN, Chen-Yen LAI, Chih-Wei HSU
  • Publication number: 20210152826
    Abstract: A method for specifying layout of subpictures is provided. A video decoder receives data from a bitstream to be decoded as a current picture of a video. The video decoder parses the bitstream for positions and sizes of multiple subpictures of the current picture. A position of a first subpicture and a size of a last subpicture are skipped during the parsing. The video decoder reconstructs the current picture and the subpictures of the current picture according to the positions and the sizes of the subpictures.
    Type: Application
    Filed: November 12, 2020
    Publication date: May 20, 2021
    Inventors: Lulin Chen, Chun-Chia Chen, Chih-Wei Hsu, Ching-Yeh Chen, Chen-Yen Lai
  • Publication number: 20210136420
    Abstract: Methods and apparatus for video coding are disclosed. According to one method, a bitstream is generated or received, where the bitstream includes a first syntax and a second syntax. The first syntax is related to a target number of bits used to represent a set of third syntaxes and each third syntax specifies one subpicture ID for one subpicture in a set of subpictures. The second syntax is related to a total number of subpictures in the set of subpicture, where a first number that can be represented by the target number of bits is equal to or greater than the total number of subpictures. According to another method, the subpicture ID syntaxes have different values for different subpictures.
    Type: Application
    Filed: November 3, 2020
    Publication date: May 6, 2021
    Inventors: Chen-Yen LAI, Shih-Ta HSIANG, Olena CHUBACH, Tzu-Der CHUANG, Ching-Yeh CHEN, Lulin CHEN
  • Publication number: 20210112247
    Abstract: A video system that applies constraints on block partitioning is provided. The system receives a partitioning control parameter from a bitstream specifying a maximum block size for enabling ternary-tree split that is constrained to be 64 or smaller. The system receives data from a bitstream for a block of pixels to be decoded as a current block of a current picture of a video. The system splits the current block into one or more partitions recursively, wherein ternary split is disallowed for a partition of the current block unless the partition is less than or equal to the maximum block size. The system reconstructs the one or more partitions of the current block.
    Type: Application
    Filed: October 12, 2020
    Publication date: April 15, 2021
    Inventors: Shih-Ta Hsiang, Chen-Yen Lai, Ching-Yeh Chen
  • Publication number: 20210092361
    Abstract: A method for signaling scaling matrices for transform coefficient quantization is provided. A decoder receives data from a bitstream to be decoded as a current picture of a video, the current picture to be decoded by using a plurality of scaling matrices. The decoder receives a reference index offset for a first scaling matrix of the plurality of scaling matrices. The decoder applies the reference index offset to a first index identifying the first scaling matrix to derive a second index identifying a second scaling matrix of the plurality of scaling matrices. The second scaling matrix is previously reconstructed. The decoder reconstructs the first scaling matrix by referencing the second scaling matrix. The decoder dequantizes transform coefficients of transform blocks of the current picture by using the plurality of scaling matrices and reconstructs the current picture by using the dequantized transform coefficients.
    Type: Application
    Filed: September 23, 2020
    Publication date: March 25, 2021
    Inventors: Chen-Yen Lai, Olena Chubach, Tzu-Der Chuang, Ching-Yeh Chen
  • Publication number: 20210014536
    Abstract: In one method, the current block is partitioned into multiple final sub-blocks using one or more stages of sub-tree partition comprising ternary tree partition and at least one other-type partition, where ternary partition tree is excluded from the sub-tree partition if a current sub-tree depth associated with a current sub-block is greater than a first threshold and the first threshold is an integer greater than or equal to 1. In another method, if a test condition is satisfied, the current block is encoded or decoded using a current Inter mode selected from a modified group of Inter tools, where the modified group of Inter tools is derived from an initial group of Inter tools by removing one or more first Inter tools from the initial group of Inter tools, replacing one or more second Inter tools with one or more complexity-reduced Inter tools, or both.
    Type: Application
    Filed: March 13, 2019
    Publication date: January 14, 2021
    Inventors: Chun-Chia CHEN, Chia-Ming TSAI, Yu-Chi SU, Chen-Yen LAI, Chih-Wei HSU, Ching-Yeh CHEN, Tzu-Der CHUANG, Yu-Wen HUANG, Han HUANG
  • Publication number: 20210006795
    Abstract: A method for signaling scaling matrices for transform coefficient quantization is provided. A video decoder receives data from a bitstream to be decoded as a current picture of a video. The video decoder determines a plurality of scaling matrices that are used to code the current picture, wherein a first scaling matrix of the plurality of scaling matrices is determined by referencing a previously determined second scaling matrix of the plurality of scaling matrices. The video decoder dequantizes transform coefficients of transform blocks of the current picture by using the determined plurality of scaling matrices. The video decoder reconstructs the current picture by using the dequantized transform coefficients.
    Type: Application
    Filed: July 6, 2020
    Publication date: January 7, 2021
    Inventors: Chen-Yen Lai, Olena Chubach, Tzu-Der Chuang, Ching-Yeh Chen, Chih-Wei Hsu, Yu-Wen Huang
  • Publication number: 20200396467
    Abstract: Video processing methods include receiving input data of a current block in a current picture, determining if a luma component and chroma components of the current block are coded using different splitting trees, disabling Adaptive Colour Transform (ACT) on the current block when the luma component and the chroma components of the current block are coded using different splitting trees, and encoding or decoding the current block. ACT is only allowed to be performed on blocks coded in single tree block partitioning to convert a RGB colour space into an YCoCg colour space. ACT is applied to residues according to some embodiments, or ACT is applied to input data and predictors according to some other embodiments.
    Type: Application
    Filed: June 10, 2020
    Publication date: December 17, 2020
    Inventors: Chen-Yen LAI, Tzu-Der CHUANG, Ching-Yeh CHEN