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.

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.

An inter prediction method allows a variable coefficient deep learning model to adaptively learn characteristics of a video; transmits a variable coefficient deep learning model parameter generated from the learning from an image encoding device to an image decoding device; and refers to a virtual reference frame generated by the variable coefficient deep learning model.

A method for decoding an image, according to the present document, comprises: receiving a bitstream including BDPCM information; deriving residual samples for a current block on the basis of the BDPCM information; deriving prediction samples for the current block on the basis of the BDPCM information; generating a reconstructed picture on the basis of the residual samples and the prediction samples; and performing deblocking filtering on the reconstructed picture, wherein when BDPCM is applied to the current block, the deblocking filtering is not performed.

A method for decoding an image, according to the present document, comprises: receiving a bitstream including BDPCM information; deriving residual samples for a current block on the basis of the BDPCM information; deriving prediction samples for the current block on the basis of the BDPCM information; generating a reconstructed picture on the basis of the residual samples and the prediction samples; and performing deblocking filtering on the reconstructed picture, wherein when BDPCM is applied to the current block, the deblocking filtering is not performed.

A decoding method performed by a decoding apparatus, according to embodiments of the present document, may comprise the steps of: acquiring, via a bitstream, image information including residual information; generating reconstructed samples of a current picture on the basis of the residual information; and generating modified reconstructed samples by performing an in-loop filtering procedure on the reconstructed samples of the current picture, wherein whether or not the in-loop filtering procedure is performed across virtual boundaries is determined. The virtual boundaries can bring, to the decoding apparatus, advantages from a hardware perspective.

A decoding method performed by a decoding apparatus, according to embodiments of the present document, may comprise the steps of: acquiring, via a bitstream, image information including residual information; generating reconstructed samples of a current picture on the basis of the residual information; and generating modified reconstructed samples by performing an in-loop filtering procedure on the reconstructed samples of the current picture, wherein whether or not the in-loop filtering procedure is performed across virtual boundaries is determined. The virtual boundaries can bring, to the decoding apparatus, advantages from a hardware perspective.

In a method, a filter shape is determined from a plurality of filter shapes of a sample offset filter to be applied to a reconstructed sample of a current component in a current picture. A coded video bitstream is generated based on samples of the current picture and the determined filter shape of the sample offset filter. The coded video bitstream includes coded information that indicates the filter shape. A top most sample of the first reconstructed samples in the plurality of filter shapes is located within a first predetermined number of top rows above a center reconstructed sample of the first component that is co-located with the reconstructed sample of the current component. A bottom most sample of the first reconstructed samples in the plurality of filter shapes is located within a second predetermined number of bottom rows below the center reconstructed sample of the first component.

In a method, a filter shape is determined from a plurality of filter shapes of a sample offset filter to be applied to a reconstructed sample of a current component in a current picture. A coded video bitstream is generated based on samples of the current picture and the determined filter shape of the sample offset filter. The coded video bitstream includes coded information that indicates the filter shape. A top most sample of the first reconstructed samples in the plurality of filter shapes is located within a first predetermined number of top rows above a center reconstructed sample of the first component that is co-located with the reconstructed sample of the current component. A bottom most sample of the first reconstructed samples in the plurality of filter shapes is located within a second predetermined number of bottom rows below the center reconstructed sample of the first component.

An image decoding method according to embodiments of the present document may comprise the steps of: acquiring, via a bitstream, image information including residual information; generating reconstruction samples on the basis of the residual information; and performing an in-loop filtering procedure for the reconstruction samples so as to generate modified reconstruction samples. The step of generating of the modified reconstruction samples may comprise a step of determining whether the in-loop filtering procedure is performed across virtual boundaries. In an example, wherein the image information includes an SPS, and on the basis of whether reference picture resampling is available, whether the SPS includes additional virtual boundary-related information may be determined.