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CN-122003866-A - Shared buffer method and apparatus for extrapolating intra prediction model inheritance in video encoding and decoding

CN122003866ACN 122003866 ACN122003866 ACN 122003866ACN-122003866-A

Abstract

A video encoding and decoding method and apparatus using an extrapolated intra prediction (Extrapolation Intra Prediction, EIP) mode correlation mode are disclosed. According to the method, input data associated with a current block is received, wherein the input data comprises pixel data to be encoded at an encoder side or data associated with the current block to be decoded at a decoder side. The current block is encoded or decoded using an Extrapolated Intra Prediction (EIP) mode. After encoding or decoding the current block, at least part of the EIP information associated with the EIP mode is stored in a shared buffer shared with inter-frame codec information associated with the inter-frame mode, wherein the EIP information and the inter-frame codec information are used for codec information inheritance to encode or decode subsequent video data.

Inventors

  • ZHUANG ZHENGYAN
  • ZENG XINYI
  • CHEN QIWEN
  • ZHUANG ZIDE
  • CHEN QINGYE
  • XU ZHIWEI
  • HUANG YUWEN

Assignees

  • 联发科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241010
Priority Date
20231012

Claims (20)

  1. 1. A video encoding and decoding method, the method comprising: Receiving input data associated with a current block, wherein the input data comprises pixel data to be encoded at an encoder side or data associated with the current block to be decoded at a decoder side; Encoding or decoding the current block using an Extrapolated Intra Prediction (EIP) mode, and After encoding or decoding the current block, at least part of the EIP information associated with the EIP mode is stored in a shared buffer shared with inter-frame codec information associated with the inter-frame mode, wherein the EIP information and the inter-frame codec information are used for codec information inheritance to encode or decode subsequent video data.
  2. 2. The method of claim 1, wherein the EIP information includes template type, kernel shape, related sub-mode flags, model parameters, or a combination thereof.
  3. 3. The method of claim 1, wherein the inter-frame codec information comprises one or more motion vectors.
  4. 4. The method of claim 1, wherein CTU-level buffers and picture-level buffers are used as the shared buffer to store the EIP information and the inter-frame codec information respectively related to a current CTU and a current picture.
  5. 5. The method of claim 4, wherein the buffer size of the CTU stage buffer corresponds to a total number of minimum allowed size blocks in each CTU.
  6. 6. The method of claim 5, wherein a buffer size of the picture level buffer corresponds to a total number of second blocks in each picture, wherein a width of the second blocks is greater than or equal to a width of the minimum allowed size block and a height of the second blocks is greater than or equal to a height of the minimum allowed size block.
  7. 7. The method of claim 5, wherein after encoding or decoding the current block, the EIP information of the current block is first saved to one or more corresponding locations of the CTU level buffer in units of the minimum allowable-size block, wherein the one or more corresponding locations of the CTU level buffer correspond to one or more target locations covered by the current block in units of the minimum allowable-size block.
  8. 8. The method of claim 5, wherein after encoding or decoding the current CTU, the EIP information or the inter-frame codec information in a CTU level buffer is saved to one or more corresponding locations of the picture level buffer in units of a second block, wherein a width of the second block is greater than or equal to a width of the minimum allowable size block and a height of the second block is greater than or equal to a height of the minimum allowable size block.
  9. 9. The method of claim 8, wherein if a block size of the second block is not the same as a block size of the minimum allowable-size block, the EIP information or the inter-frame codec information in the CTU level buffer is to be sub-sampled to be saved to the picture level buffer.
  10. 10. The method of claim 9, wherein if the size ratio of the second block and the minimum allowable-size block is g x h, one of every g x h grid of the CTU level buffer is selected to hold the EIP information or the inter-frame codec information to a corresponding location of the picture level buffer, wherein g and h correspond to a horizontal ratio and a vertical ratio, respectively, and g and h are integers greater than or equal to 1.
  11. 11. The method of claim 10, wherein a selected one of each gxh trellis of the CTU stage buffer corresponds to an upper left, lower left, upper right, or lower right position of each gxh trellis.
  12. 12. The method of claim 5, wherein when the EIP information or the inter-frame codec information in the CTU level buffer is sub-sampled to be saved to the picture level buffer, a prediction mode within each gxh grid is checked to determine target codec information selected from the each gxh grid.
  13. 13. The method of claim 12, wherein the target codec information corresponds to the EIP information if a majority of prediction modes within each gxh grid are intra prediction modes.
  14. 14. The method of claim 13, wherein if the target codec information corresponds to the EIP information, the target codec information is selected from the first grid of each gxh grid according to a predetermined scan order within the each gxh grid with the EIP information.
  15. 15. The method of claim 12, wherein the target codec information corresponds to the inter-frame codec information if a majority of prediction modes within each gxh grid are inter-frame prediction modes.
  16. 16. The method of claim 15, wherein if the target codec information corresponds to the inter-frame codec information, the target codec information is selected from the first grid of each gxh grid according to a predetermined scan order within the each gxh grid with the inter-frame codec information.
  17. 17. The method of claim 1, wherein the target codec information stored in the target buffer location of the shared buffer is determined based on a codec mode of a target block associated with the target buffer location.
  18. 18. The method of claim 17, wherein the target codec information corresponds to the EIP information if the codec mode of the target block is an intra prediction mode.
  19. 19. The method of claim 17, wherein the target codec information corresponds to the inter-codec information if the codec mode of the target block is a non-intra-prediction mode.
  20. 20. The method of claim 17, wherein the target codec information corresponds to the EIP information if the codec mode is set to an invalid inter prediction reference index or an invalid MV value.

Description

Shared buffer method and apparatus for extrapolating intra prediction model inheritance in video encoding and decoding [ Cross-reference ] The present invention is a non-provisional application and claims priority from U.S. provisional patent application No. 63/589,658 filed on day 10, 2023. This U.S. provisional patent application is incorporated herein by reference in its entirety. [ Field of technology ] The present invention relates to video coding and decoding systems using an extrapolated intra prediction (Extrapolation Intra Prediction, EIP) mode. In particular, the present invention relates to storing EIP information in a shared buffer that is shared with inter-frame codec information. [ Background Art ] The universal video codec (VVC) is the latest international video codec standard established by the joint video expert group (JVET) of the ITU-T Video Codec Expert Group (VCEG) and the ISO/IEC Moving Picture Expert Group (MPEG). The standard has been published as an ISO standard for release for month ：ISO/IEC 23090-3:2021,Information technology - Coded representation of immersive media - Part 3: Versatile video coding,2021 , 2. VVC was developed by adding more codec tools to improve codec efficiency based on its predecessor HEVC (HIGH EFFICIENCY Video coding), and processing various types of Video sources, including 3-dimensional (3D) Video signals. Fig. 1A illustrates an exemplary adaptive inter/Intra (ADAPTIVE INTER/Intra) video codec system that includes loop processing. For intra prediction, prediction data is derived (derived) from previously encoded video data in a current picture (hereinafter also referred to as picture). For inter prediction 112, motion estimation (Motion Estimation, abbreviated ME) is performed at the encoder side and motion compensation (Motion Compensation, abbreviated MC) is performed based on the results of ME to provide prediction data derived from other pictures and motion data. The switch 114 selects either the intra prediction 110 or the inter prediction 112 and the selected prediction data is provided to the adder 116 to form a prediction error, also referred to as residual. The prediction error is then processed by transform (T) 118 and subsequent quantization (Q) 120. The transformed and quantized residual is then encoded by entropy encoder 122 for inclusion in a video bitstream corresponding to the compressed video data. The bitstream associated with the transform coefficients is then packetized with side information (e.g., motion and decoding modes associated with intra and inter prediction) and other information (e.g., parameters associated with loop filters applied to the underlying image region (underlying IMAGE AREA)). Side information associated with intra prediction 110, inter prediction 112, and loop filter 130 is provided to entropy encoder 122, as shown in fig. 1A. When inter prediction modes are used, one or more reference pictures must also be reconstructed at the encoder side. Thus, the transformed and quantized residual is processed by Inverse Quantization (IQ) 124 and Inverse Transform (IT) 126 to recover the residual. The residual is then added back to the prediction data 136 at Reconstruction (REC) 128 to reconstruct the video data. The reconstructed video data may be stored in a reference picture buffer 134 and used to predict other frames. As shown in fig. 1A, input video data is subjected to a series of processes in an encoding system. The reconstructed video data from REC 128 may suffer from various impairments due to a series of processes. Thus, loop filter 130 is often applied to the reconstructed video data before it is stored in reference picture buffer 134 to improve video quality. For example, a deblocking filter (deblocking filter, abbreviated DF), a sample adaptive Offset (SAMPLE ADAPTIVE Offset, abbreviated SAO), and an adaptive loop filter (Adaptive Loop Filter, abbreviated ALF) may be used. It may be necessary to incorporate loop filter information into the bitstream so that the decoder can correctly recover the required information. Thus, loop filter information is also provided to entropy encoder 122 for incorporation into the bitstream. In fig. 1A, loop filter 130 is applied to the reconstructed video before the reconstructed samples are stored in reference picture buffer 134. The system in fig. 1A is intended to illustrate an exemplary architecture of a typical video encoder. It may correspond to an efficient video codec (HEVC) system, VP8, VP9, h.264, or VVC. As shown in fig. 1B, the decoder may use similar or identical functional blocks to the encoder in addition to the transform 118 and quantization 120, as the decoder only requires inverse quantization 124 and inverse transform 126. The decoder uses the entropy decoder 140 instead of the entropy encoder 122 to decode the video bitstream into quantized transform coefficients and required codec information (e.g., ILPF information, intra-prediction information, and inter-pred