BR-112019002896-B1 - METHOD OF ENCODING VIDEO DATA, DEVICE AND COMPUTER-READABLE MEMORY

BR112019002896B1BR 112019002896 B1BR112019002896 B1BR 112019002896B1BR-112019002896-B1

Abstract

The present invention relates to an exemplary device comprising a memory and a processing circuitry in communication with the memory. The processing circuitry of a device is configured to form a most likely mode (MMP) candidate list for a chroma block of video data stored in memory, such that the MMP candidate list includes one or more derived modes (DMs) associated with a luma block of video data associated with the chroma block, and a plurality of luma prediction modes that can be used to encode the luminescence components of the video data. The processing circuitry is further configured to select a mode from the MMP candidate list, and to encode the chroma block according to the mode selected from the MMP candidate list.

Inventors

Li Zhang
Wei-Jung Chien
Jianle Chen
Xin Zhao
Marta Karczewicz

Assignees

QUALCOMM INCORPORATED

Dates

Publication Date: 20260317
Application Date: 20170815
Priority Date: 20170814

Claims (9)

1. Video data encoding method, the method comprising: determining an intraprediction mode for a chroma (178) prediction unit of a chroma (176, 204) block of video data based on an intraprediction mode of a luma prediction unit in a corresponding luma (172, 202) block, wherein the partitioning of the corresponding luma block into luma prediction units is determined using a first tree structure that is independent of a second tree structure that determines the partitioning of the chroma block into chroma prediction units, the first and second tree structures being quaternary-binary tree structures, and encoding the chroma prediction unit according to the determined intraprediction mode; characterized in that the step of determining an intraprediction mode for a chroma prediction unit of a chroma block based on an intraprediction mode of a luma prediction unit in a luma block The corresponding function comprises: determining one of a plurality of luma prediction units from the corresponding luma block that is located at a position corresponding to a central position of the luma block corresponding to the chroma block, wherein the central position is defined according to a coordinate tuple including an x-coordinate defined using twice the horizontal offset of the chroma block and a y-coordinate defined using twice the vertical offset of the chroma block, wherein the coordinate tuple is based on the width W and height H of the chroma block such that a given unit from the plurality of luma prediction units is at the central position having the coordinate tuple 2x + W - 1, 2y + H - 1; and deriving a derivative mode, DM, for the chroma mode from a luma mode associated with the luma prediction unit located at the central position of the corresponding luma block partition; wherein the video data is in 4:2:0 color format.
2. A method according to claim 1, characterized in that encoding the chroma block comprises decoding the chroma block.
3. Method according to claim 1, characterized in that encoding the chroma block comprises encoding the chroma block.
4. Device comprising: a memory configured to store video data; a processing circuit in communication with memory, the processing circuit being configured to: determine an intraprediction mode for a chroma prediction unit (178) of a chroma block (176, 204) of the video data based on an intraprediction mode of a luma prediction unit in a corresponding luma block (172, 202), wherein the partitioning of the corresponding luma block into luma prediction units is determined using a first tree structure that is independent of a second tree structure that determines the partitioning of the chroma block into chroma prediction units, the first and second tree structures being quaternary-binary tree structures, and encode the chroma prediction unit according to the determined intraprediction mode; characterized in that determining an intraprediction mode for a chroma prediction unit of the chroma block is based on an intraprediction mode of a luma prediction unit in a block of corresponding luma, the processing circuit being configured to: determine one of a plurality of luma prediction units from the corresponding luma block that is located at a position corresponding to a central position of the luma block corresponding to the chroma block, wherein the central position is defined according to a coordinate tuple including an x-coordinate defined using twice the horizontal offset of the chroma block and a y-coordinate defined using twice the vertical offset of the chroma block, wherein the coordinate tuple is based on the width W and height H of the chroma block such that a given unit of the plurality of luma prediction units is at the central position having the coordinate tuple 2x + W - 1, 2y + H - 1; and derive a derived mode, DM, for the chroma mode from a luma mode associated with the luma prediction unit located at the central position of the corresponding luma block partition; wherein the video data is in 4:2:0 color format.
5. Device according to claim 4, characterized in that to encode the chroma block, the processing circuit is configured to decode the chroma block.
6. Device according to claim 5, characterized in that it further comprises a monitor configured to display an image that includes the decoded chroma block.
7. Device according to claim 4, characterized in that to encode the chroma block, the processing circuit is configured to encode the chroma block.
8. Device according to claim 7, characterized in that it further comprises a camera configured to capture an image that includes the chroma block.
9. Computer-readable memory comprising instructions stored therein, the instructions being executable by the processor to perform the steps of: determining an intraprediction mode for a chroma prediction unit (178) of a chroma block (176, 204) of the video data based on an intraprediction mode of a luma prediction unit in a corresponding luma block (172, 202), wherein the partitioning of the corresponding luma block into luma prediction units is determined using a first tree structure that is independent of a second tree structure that determines the partitioning of the chroma block into chroma prediction units, the first and second tree structures being quaternary-binary tree structures, and encoding the chroma prediction unit according to the determined intraprediction mode; characterized in that, to determine an intraprediction mode for a chroma prediction unit of a chroma block based on an intraprediction mode of a luma prediction unit in a corresponding luma block, the instructions make the processor: determine one of a plurality of luma prediction units of the corresponding luma block that is located at a position corresponding to a center position of the luma block corresponding to the chroma block, wherein the center position is defined according to a coordinate tuple including an x coordinate defined using twice the horizontal offset of the chroma block and a y coordinate defined using twice the vertical offset of the chroma block, wherein the coordinate tuple is based on the width W and height H of the chroma block such that a given unit of the plurality of luma prediction units is at the center position having the coordinate tuple 2x + W - 1, 2y + H - 1; to derive a derived mode, DM, for the chroma mode from a luma mode associated with the luma prediction unit located in the central position of the corresponding luma block partition; wherein the video data is in 4:2:0 color format.

Description

[0001] This application claims the benefit of Provisional Application No. U.S. 62/375,383, filed August 15, 2016, and Provisional Application No. U.S. 62/404,572, filed October 5, 2016, the full contents of which are incorporated by reference. FIELD OF TECHNIQUE [0002] This revelation refers to video encoding. BACKGROUND [0003] Digital video capabilities can be incorporated into a wide range of devices, including digital televisions, digital direct broadcast systems, wireless broadcast systems, personal digital subscribers (PDAs), laptop or desktop computers, tablet computers, e-readers, digital cameras, digital recording devices, digital media players, video game devices, video game consoles, satellite or cellular radio telephones, referred to as “smartphones”, video teleconferencing devices and the like. Digital video devices implement video encoding techniques, such as those described in the standards defined by various video encoding standards. Video coding standards include ITU-T H.261, ISO/IEC MPEG-1 Visual, ITU-T H.262 or ISO/IEC MPEG-2 Visual, ITU-T H.263, ISO/IEC MPEG-4 Visual, and ITU-T H.264 (also known as ISO/IEC MPEG-4 AVC), including their Scalable Code Video Transformation (SVC) and Multi-View Code Video Transformation (MVC) extensions. [0004] In addition, a new video decoding standard, namely High Efficiency Video Coding (HEVC), has been developed by the Joint Collaboration Team on Video Coding (JCT-VC) of the ITU-T Video Coding Expert Group (VCEG) and the ISO/IEC Motion Picture Expert Group (MPEG). The latest draft specification of HEVC, hereinafter referred to as "HEVC WD", is available at http://phenix.int-evry.fr/jct/doc_end_user/documents/14_Vienna/wgl/JCTVC-N1003-vl.zip. The HEVC specification and its extensions, which include Format Range (RExt), Scalability (SHVC), and Multi-View Extensions (MV-HEVC) and Screen Content Extensions, are available at http://phenix.int-evry.fr/jct/doc_end_user/current_document.php?id=10481. ITU-T VCEG (Q6/16) and ISO/IEC MPEG (JTC 1/SC 29/WG 11) are now studying the potential needed for standardizing future video coding technology with a compression capability that significantly exceeds that of the current HEVC standard (which includes its current extensions and short-term extensions for screen content coding and high dynamic range coding). [0005] The groups work together in their exploration activity in a joint collaborative effort known as the Joint Video Exploration Team (JVET) to evaluate compression technology designs proposed by their experts in this area. The JVET first met between 19 and 21 October 2015. The latest version of the reference software, i.e., Joint Exploration Model 3 (JEM 3), can be downloaded from: https://jvet.hhi.fraunhofer.de/svn/svn_HMJEMSoftware/tags/H M-16.6-JEM-3.0/. The algorithm description for JEM3 is further described in "Algorithm description of Joint Exploration Test Model 3" by J. Chen, E. Alshina, G. J. Sullivan, J.-R. Ohm, J. Boyce, JVET-CIOOI, Geneva, June 2016. [0006] Video devices can transmit, receive, encode, decode, and/or store digital video information more efficiently by implementing such video coding techniques. Video coding techniques include spatial (intra-image) and/or temporal (inter-image) prediction to reduce or remove inherent redundancy in video sequences. For block-based video coding, a video slice (e.g., a video frame or a portion of a video frame) can be partitioned into video blocks, which for some techniques may also be referred to as treeblocks, coding units (CUs), and/or coding nodes. Video blocks in an intracoded slice (I) of an image are coded using spatial prediction relative to reference samples in neighboring blocks in the same image. Video blocks in an intercoded slice (P or B) of an image can use spatial prediction relative to reference samples in neighboring blocks in the same image or temporal prediction relative to reference samples in other reference images. Images can be referred to as frames, and reference images can be referred to as reference frames. [0007] Temporal or spatial prediction results in a predictive block for a block to be encoded. Residual data represents pixel differences between the original block to be encoded and the predictive block. An intercoded block is encoded according to a motion vector that aims at a block of reference samples that form the predictive block, and residual data indicating the difference between the encoded block and the predictive block. An intracoded block is encoded according to an intracoding mode and residual data. For further compression, residual data can be transformed from the pixel domain to a transform domain, resulting in residual transform coefficients, which can then be quantized. The quantized transform coefficients, initially arranged in a two-dimensional array, can be scanned to produce a one-dimensional vector of transform coefficients, and entropy encoding can be applied to achieve even greater compression. SUMMARY [000