US Patent 11190794 Method and apparatus for video coding

Aspects of the disclosure provide methods and apparatuses for video encoding/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 can indicate a region of the TB on which a secondary transform is applied. The region can include a first sub-region having transform coefficients calculated by the secondary transform and a second sub-region. The processing circuitry can determine, for a transform coefficient in the TB, whether a neighboring transform coefficient used to determine the transform coefficient is located in the second sub-region. When the neighboring transform coefficient is determined to be located in the second sub-region, the processing circuitry can determine the transform coefficient according to a default value for the neighboring transform coefficient and reconstruct a sample in the TB based on the transform coefficient for the sample.