A scalable video decoder is described which is configured to reconstruct a base layer signal from a coded data stream to obtain a reconstructed base layer signal; and reconstruct an enhancement layer signal including spatially or temporally predicting a portion of an enhancement layer signal, currently to be reconstructed, from an already reconstructed portion of the enhancement layer signal to obtain an enhancement layer internal prediction signal; forming, at the portion currently to be reconstructed, a weighted average of an inter-layer prediction signal obtained from the reconstructed base layer signal, and the enhancement layer internal prediction signal to obtain an enhancement layer prediction signal such that a weighting between the inter-layer prediction signal and the enhancement layer internal prediction signal varies over different spatial frequency components; and predictively reconstructing the enhancement layer signal using the enhancement layer prediction signal.

A scalable video decoder is described which is configured to reconstruct a base layer signal from a coded data stream to obtain a reconstructed base layer signal; and reconstruct an enhancement layer signal including spatially or temporally predicting a portion of an enhancement layer signal, currently to be reconstructed, from an already reconstructed portion of the enhancement layer signal to obtain an enhancement layer internal prediction signal; forming, at the portion currently to be reconstructed, a weighted average of an inter-layer prediction signal obtained from the reconstructed base layer signal, and the enhancement layer internal prediction signal to obtain an enhancement layer prediction signal such that a weighting between the inter-layer prediction signal and the enhancement layer internal prediction signal varies over different spatial frequency components; and predictively reconstructing the enhancement layer signal using the enhancement layer prediction signal.

Aspects of the disclosure provide methods and apparatuses for video encoding and/or decoding. In some examples, an apparatus for video decoding includes processing circuitry that can decode coded information of a transform block (TB) from a coded video bitstream. The coded information indicates a region of the TB on which a secondary transform is applied. The region includes a first sub-region having transform coefficients calculated by the secondary transform and a second sub-region that is a zero-out region. In response to a determination that a neighboring transform coefficient is in the second sub-region and a current transform coefficient in the TB is not in the second sub-region, the processing circuitry determines the current transform coefficient according to a default value for the neighboring transform coefficient. The processing circuitry reconstructs a sample in the TB based on the transform coefficient for the sample.

Aspects of the disclosure provide methods and apparatuses for video encoding and/or decoding. In some examples, an apparatus for video decoding includes processing circuitry that can decode coded information of a transform block (TB) from a coded video bitstream. The coded information indicates a region of the TB on which a secondary transform is applied. The region includes a first sub-region having transform coefficients calculated by the secondary transform and a second sub-region that is a zero-out region. In response to a determination that a neighboring transform coefficient is in the second sub-region and a current transform coefficient in the TB is not in the second sub-region, the processing circuitry determines the current transform coefficient according to a default value for the neighboring transform coefficient. The processing circuitry reconstructs a sample in the TB based on the transform coefficient for the sample.

A method of video decoding comprises receiving a bitstream including a SPS, a PPS, and subpictures associated with a subpicture ID mapping. A determination is made of whether an SPS flag has a first or second value. The SPS flag having the first value specifies that the subpicture ID mapping is signaled in the SPS, and the second value specifies that the subpicture ID mapping is signaled in the PPS. The subpicture ID mapping is obtained from the SPS when the SPS flag has the first value and from the PPS when the SPS flag has the second value or the PPS flag has the first value.

A video processing method includes determining, for a conversion between a current block of a video and a bitstream representation of the video, whether to enable a level mapping operation or a level remapping operation based on a rule, wherein the level mapping operation or the level remapping operation includes changing between a first representation of a residual coefficient of the current block and a second representation of the residual coefficient of the current block based on neighboring residual coefficients of the residual coefficient; and performing the conversion by selectively using the level mapping operation or the level remapping operation based on the determining.

A video processing method includes determining, for a conversion between a current block of a video and a bitstream representation of the video, whether to enable a level mapping operation or a level remapping operation based on a rule, wherein the level mapping operation or the level remapping operation includes changing between a first representation of a residual coefficient of the current block and a second representation of the residual coefficient of the current block based on neighboring residual coefficients of the residual coefficient; and performing the conversion by selectively using the level mapping operation or the level remapping operation based on the determining.

The present disclosure relates to a processing method of a video signal, the processing method comprising the steps of: scaling a transform coefficient for a current block on the basis of an intermediate scaling factor array; when the flag indicates that a low frequency non-separable transform is applied to the current block, obtaining a residual for the current block by applying an inverse transform of a non-separable transform and an inverse transform of a primary transform on the scaled transform coefficient, wherein the primary transform is a transform applied to a residual signal of a spatial domain before the low frequency non-separable transform; and reconstructing the current block on the basis of the residual and a predictor of the current block.

A display apparatus includes an encoder which compresses first image data to generate second image data, a decoder which recovers the first image data to generate third image data, and a display panel which displays an image, in which the encoder separates the first image data into a plurality of sub-color data, and generates a low frequency component of minor sub-color data among the plurality of sub-color data and the remaining sub-color data as the second image data, and the decoder generates recovery minor sub-color data corresponding to the minor sub-color data by using the low frequency component of the minor sub-color data and the high frequency component of one of the remaining sub-color data in the second image data, and generates the recovery minor sub-color data and the remaining sub-color data as the third image data.

Video processing methods and apparatuses in a video encoding or decoding system for transforming residuals of transform blocks into final transform coefficients or inverse transforming final transform coefficients into residuals. In order to solve the latency issue, exemplary embodiments check if a width or height of a coding block is larger than a predefined threshold, and disable secondary transform or inverse secondary transform for any transform block within the coding block if the width or height of the coding block is larger than the predefined threshold. Another embodiment checks if there are multiple transform blocks in a coding block, and disables secondary transform or inverse secondary transform if the coding block contains multiple transform blocks.