Aspects of the disclosure provide methods, apparatuses, and non-transitory computer-readable storage mediums for video encoding/decoding. In a method, prediction information for a current block is decoded. The current block is in a current picture that is a part of a coded video sequence. The prediction information indicates a first intra prediction mode and a secondary transform index for the current block. A secondary transform core is determined based on the first intra prediction mode and the secondary transform index. A primary transform coefficient block is generated based on the secondary transform core and a first transform coefficient block of the current block. The first transform coefficient block is de-quantized from the prediction information. A size of the first transform coefficient block is less than a size of the secondary transform core. The current block is reconstructed based on the primary transform coefficient block.