A video decoding method performed by a video decoding device according to the present document may comprise the steps of: acquiring image information from a bitstream, the image information including a picture header associated with the current picture including a plurality of slices; parsing, from the picture header, at least one of a first flag indicating whether information necessary for an inter-prediction operation for a decoding process is present in the picture header, or a second flag indicating whether information necessary for an intra-prediction operation for the decoding process is present in the picture header; generating prediction samples by performing at least one of intra-prediction or inter-prediction for the slices in the current picture on the basis of at least one of the first flag or the second flag; and generating reconstructed samples on the basis of the prediction samples.

Apparatus and methods for implementing a real-time Versatile Video Coding (VVC) decoder use multiple threads to address the limitation with existing parallelization techniques and fully utilizes the available CPU computation resource without compromising on the coding efficiency. The proposed Multi-threaded (MT) framework uses CTU level parallel processing techniques without compromising on the memory bandwidth. Picture level parallel processing separates the sequence into temporal levels by considering the picture's referencing hierarchy. Embodiments are provided using various optimization techniques to achieve real-time VVC decoding on heterogenous platforms with multi-core CPUs, for those bitstreams generated using a VVC reference encoder with a default configuration.

This disclosure relates to a video compression method, apparatus, and device, and a medium. The method includes: obtaining a video frame, where the video frame includes a first dynamic group of pictures and a second dynamic group of pictures; extracting a first I frame in the first dynamic group of pictures, and extracting a second I frame in the second dynamic group of pictures; deleting duplicate data between the first I frame and the second I frame, to obtain a target I frame; and compressing the target I frame. The duplicate data between the first I frame and the second I frame is deleted, and this does not affect integrity of data of the video frame.

This disclosure relates to a video compression method, apparatus, and device, and a medium. The method includes: obtaining a video frame, where the video frame includes a first dynamic group of pictures and a second dynamic group of pictures; extracting a first I frame in the first dynamic group of pictures, and extracting a second I frame in the second dynamic group of pictures; deleting duplicate data between the first I frame and the second I frame, to obtain a target I frame; and compressing the target I frame. The duplicate data between the first I frame and the second I frame is deleted, and this does not affect integrity of data of the video frame.

Methods, devices and systems for configuring different access units in scalable video coding are described. In one example aspect, a method of video processing include performing a conversion between a video comprising one or more pictures in one or more video layers and a bitstream of a video, wherein the bitstream comprises a coded video sequence that includes one or more access units, and wherein the bitstream further comprises a first syntax element indicating whether an access unit includes a picture for each video layer making up the coded video sequence.

Devices, systems and methods for palette mode coding are described. An exemplary method for video processing includes determining, for a conversion between a block of a video region in a video and a bitstream representation of the video, a prediction mode based on one or more allowed prediction modes that include at least a palette mode of the block. An indication of usage of the palette mode is determined according to the prediction mode. The method also includes performing the conversion based on the one or more allowed prediction modes.

Devices, systems and methods for palette mode coding are described. An exemplary method for video processing includes determining, for a conversion between a block of a video region in a video and a bitstream representation of the video, a prediction mode based on one or more allowed prediction modes that include at least a palette mode of the block. An indication of usage of the palette mode is determined according to the prediction mode. The method also includes performing the conversion based on the one or more allowed prediction modes.

Disclosed are an image encoding method using a skip mode and a device using the method. The image encoding method may comprise the steps of: judging whether there is residual block data of a prediction target block on the basis of predetermined data indicating whether residual block data has been encoded; and, if there is residual block data, restoring the prediction target block on the basis of the residual block data and an intra-screen predictive value of the prediction target block. Consequently, encoding and decoding efficiency can be increased by carrying out the encoding and decoding of screen residual data only for prediction target blocks where there is a need for a residual data block in accordance with screen similarity.

Disclosed are an image encoding method using a skip mode and a device using the method. The image encoding method may comprise the steps of: judging whether there is residual block data of a prediction target block on the basis of predetermined data indicating whether residual block data has been encoded; and, if there is residual block data, restoring the prediction target block on the basis of the residual block data and an intra-screen predictive value of the prediction target block. Consequently, encoding and decoding efficiency can be increased by carrying out the encoding and decoding of screen residual data only for prediction target blocks where there is a need for a residual data block in accordance with screen similarity.

Methods, systems, apparatuses for video processing are described. A method for processing video includes performing a conversion between a video and a bitstream of the video according to a format rule, and wherein the format rule specifies to include, in a general constraint syntax structure associated with the video, one or more general constraint flags indicating whether corresponding syntax elements are included in a sequence parameter set (SPS) and/or a picture parameter set (PPS) and/or a picture header (PH) and/or a slice header (SH) or to constrain values of the syntax elements in the SPS and/or the PPS and/or the PH and/or the SH.